Return CO2 to 300 ppm

300.org exists to inform people about the Climate Emergency and the need to reduce atmospheric carbon dioxide (CO₂ ) concentration to a safe and sustainable level of about 300 ppm.

The fundamental position of 300.org is that “There must be a safe and sustainable existence for all peoples and all species on our warming-threatened Planet and this requires a rapid reduction of atmospheric carbon dioxide concentration to about 300 parts per million”. [1].

300.org urges the World to reduce atmospheric carbon dioxide concentration (CO₂) to about 300 parts per million by volume (ppm). In urging a target of an atmospheric CO₂ concentration of 300 ppm, 300.org is informed by the advice of top world climate scientists as set out below.

The World is acutely threatened by man-made global warming due to profligate greenhouse gas (GHG) pollution. The atmospheric CO₂ concentration is currently 387 ppm and increasing at about 2 ppm annually. CO₂ is a major GHG but other GHGs include methane (CH₄) and nitrous oxide (N₂O). The current atmospheric GHG concentration in units of CO₂-equivalent (CO₂-e) and including methane and nitric oxides is is about 460 ppm. The average global surface temperature is now about 0.8^oC above that in 1900. [2].

The post-1900 temperature increase of 0.8^oC has already been associated with very damaging climatic disruption, specifically increased sea levels; increased energy of tropical hurricanes; ocean warming; increased melting of glaciers; increased sea ice melting in the Arctic and Antarctic; methane release from the Arctic Ocean and tundra; increased extent of forest fires; island submergence; increased drought; increased floods; coral die off; mass species extinction at 100-1,000 times the rate indicated by the fossil record; hundreds of thousands of climate refugees; increased damage to forests; spread of insect vector-borne disease; and increased human avoidable mortality (avoidable death, excess mortality, excess death). [3, 4, 5]

The consequences of man-made global warming for ecosystems and species survival are already dire at an average global surface temperature that is currently about 0.8^oC above that in 1900. Many scientists now doubt that we can avoid further damaging temperature increases to over 2 ^oC above that in 1900. Thus a poll by the UK Guardian of scientists attending the March 2009 Copenhagen Climate Change Conference found that 90% of respondents did not believe that current political efforts would keep warming to less than 2 ^oC above that in 1900.

According to top UK climate scientist Dr James Lovelock FRS fewer than 1 billion people (evidently mostly European) will survive the century due to First World profligacy and unaddressed man-made climate change. [7].

This dire estimate of Dr James Lovelock of fewer than 1 billion survivors this century from unaddressed, man-made global warming translates to about 10 billion deaths (mostly of non-Europeans and including 3 billion Muslims, 2 billion Indians) in an already-commenced Climate Holocaust and Climate Genocide. [8].

300.org agrees with the Climate Emergency perceptions and goals of the Melbourne-based Yarra Valley Climate Action Group and specifically with what needs to be done. [9].

1. Change of societal philosophy to one of scientific risk management and biological sustainability with complete cessation of species extinctions and zero tolerance for lying.

2. Urgent reduction of atmospheric CO₂ to a safe level of about 300 ppm as recommended by leading climate and biological scientists.

3. Rapid switch to the best non-carbon and renewable energy (solar, wind, geothermal, wave, tide and hydro options that are currently roughly the same market price as coal burning-based power) and to energy efficiency, public transport, needs-based production, re-afforestation and return of carbon as biochar to soils coupled with correspondingly rapid cessation of fossil fuel burning, deforestation, methanogenic livestock production and population growth.

Inspired by the position of Dr Hansen (head, NASA GISS) that “CO₂ will need to be reduced from its current 385 ppm to at most 350 ppm” [10] the world-wide 350.org organization has the excellent position of urging a return of the atmospheric CO₂ concentration to 350 ppm or less and indeed is organizing an extremely important world-wide day of action on 24 October 2009 to publicize this position. [11].

The Australian national Climate Action Summit in Canberra (January 2009) involved over 140 community action groups and endorsed a key aim for stabilisation at 300 ppm CO₂ in the atmosphere and strong international agreement in line with what science and global justice demands. [12].

The name 300.org reflects support for the implicit 350.org goal of less than 350 ppm CO₂ (although, as detailed below, a goal of "350 ppm" is clearly inadequate according to top climate scientists) and the goal of about 300 ppm CO₂ of the 2009 Australian Climate Action Summit [12], the Australian Climate Emergency Network [13] and the Yarra Valley Climate Action Group [14].

Just as we turn to top medical specialists for advice on life-threatening disease, so we turn to the opinions of top scientists and in particular top biological and climate scientists for Climate Change risk assessment and Climate Emergency facts and requisite actions. Below are quotations from leading climate scientists and biological scientists supporting the need for an atmospheric CO₂ concentration in the range 300-350 ppm i.e. after “rounding down” and applying the “precautionary principle” of the lower safe limit, an atmospheric CO₂ concentration of about 300 ppm (the upper limit for the last 600,000 years except for the last half century or so).

1. Dr James Hansen (top US climate scientist; Director, NASA Goddard Institute for Space Studies; member of the prestigious US National Academy of Sciences; 2007 Award for Scientific Freedom and Responsibility of the prestigious American Association for the Advancement of Science; Adjunct Professor, Columbia University, New York, USA). [15].

(a) With 8 UK, French and US climate change scientist co-authors (2008): “Paleoclimate data show that climate sensitivity is ~3 deg-C for doubled CO₂ [carbon dioxide; atmospheric CO₂ 280 ppm pre-industrial], including only fast feedback processes. Equilibrium sensitivity, including slower surface albedo feedbacks, is ~6 deg-C for doubled CO₂ for the range of climate states between glacial conditions and ice-free Antarctica. Decreasing CO₂ was the main cause of a cooling trend that began 50 million years ago, large scale glaciation occurring when CO₂ fell to 450 +/- 100 ppm [parts per million], a level that will be exceeded within decades, barring prompt policy changes. If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO₂ will need to be reduced from its current 385 ppm to at most 350 ppm. The largest uncertainty in the target arises from possible changes of non-CO₂ forcings. An initial 350 ppm CO₂ target may be achievable by phasing out coal use except where CO₂ is captured and adopting agricultural and forestry practices that sequester carbon. If the present overshoot of this target CO₂ is not brief, there is a possibility of seeding irreversible catastrophic effects.” [10].

(b) In relation to the recent book “Climate Code Red. The case for emergency action” by David Spratt and Philip Sutton (Scribe, Melbourne, 2008): “A compelling case … we face a climate emergency.” [16].

(c) 2007 (Hansen, J., Mki. Sato, P. Kharecha, G. Russell, D.W. Lea, and M. Siddall, 2007: Climate change and trace gases. Phil. Trans. Royal. Soc. A, 365, 1925-1954): “Paleoclimate data show that the Earth's climate is remarkably sensitive to global forcings. Positive feedbacks predominate. This allows the entire planet to be whipsawed between climate states. One feedback, the "albedo flip" property of water substance, provides a powerful trigger mechanism. A climate forcing that "flips" the albedo of a sufficient portion of an ice sheet can spark a cataclysm. Ice sheet and ocean inertia provides only moderate delay to ice sheet disintegration and a burst of added global warming. Recent greenhouse gas (GHG) emissions place the Earth perilously close to dramatic climate change that could run out of our control, with great dangers for humans and other creatures. Carbon dioxide (CO₂) is the largest human-made climate forcing, but other trace constituents are important. Only intense simultaneous efforts to slow CO₂ emissions and reduce non-CO₂ forcings can keep climate within or near the range of the past million years. The most important of the non-CO₂ forcings is methane (CH₄), as it causes the 2nd largest human-made GHG climate forcing and is the principal cause of increased tropospheric ozone (O₃), which is the 3rd largest GHG forcing. Nitrous oxide (N₂O) should also be a focus of climate mitigation efforts. Black carbon ("black soot") has a high global warming potential (~2000, 500, and 200 for 20, 100 and 500 years, respectively) and deserves greater attention. Some forcings are especially effective at high latitudes, so concerted efforts to reduce their emissions could still "save the Arctic", while also having major benefits for human health, agricultural productivity, and the global environment.” [17].

(d) 2008, in an address to the US National Press Club and a briefing to the US House Select Committee on Energy Independence & Global Warming Congressional Committee: “CEOs of fossil energy companies know what they are doing and are aware of long-term consequences of business as usual. In my opinion, these CEOs should be tried for high crimes against humanity and nature.” [18].

(e) Dr James Hansen et al. (2008): “Stabilization of Arctic sea ice cover requires, to first approximation, restoration of planetary energy balance. Climate models driven by known forcings yield a present planetary energy imbalance of +0.5-1 W/m2. Observed heat increase in the upper 700 m of the ocean confirms the planetary energy imbalance, but observations of the entire ocean are needed for quantification. CO₂ amount must be reduced to 325-355 ppm to increase outgoing flux 0.5-1 W/m2, if other forcings are unchanged. A further imbalance reduction, and thus CO₂ ~300-325 ppm, may be needed to restore sea ice to its area of 25 years ago.” [19].

2. Dr Andrew Glikson (an Earth and paleo-climate research scientist at Australian National University, Canberra, Australia) (2009): “For some time now, climate scientists warned that melting of subpolar permafrost and warming of the Arctic Sea (up to 4 degrees C during 2005–2008 relative to the 1951–1980) are likely to result in the dissociation of methane hydrates and the release of this powerful greenhouse gas into the atmosphere (methane: 62 times the infrared warming effect of CO₂ over 20 years and 21 times over 100 years) … The amount of carbon stored in Arctic sediments and permafrost is estimated as 500–2500 Gigaton Carbon (GtC), as compared with the world’s total fossil fuel reserves estimated as 5000 GtC. Compare with the 700 GtC of the atmosphere, which regulate CO₂ levels in the range of 180–300 parts per million and land temperatures in a range of about – 50 to + 50 degrees C, which allowed the evolution of warm blooded mammals. The continuing use of the atmosphere as an open sewer for industrial pollution has already added some 305 GtC to the atmosphere together with land clearing and animal-emitted methane. This raised CO₂ levels to 387 ppm CO₂ to date, leading toward conditions which existed on Earth about 3 million years (Ma) ago (mid-Pliocene), when CO₂ levels rose to about 400 ppm, temperatures to about 2–3 degrees C and sea levels by about 25 +/- 12 metres. There is little evidence for an extinction at 3 Ma. However, by crossing above a CO₂ level of 400 ppm the atmosphere is moving into uncharted territory. At this stage, enhanced methane leaks threaten climate events, such as the massive methane release and fauna extinction of 55 million years ago, which was marked by rise of CO₂ to near-1000 ppm.” [20].

3. Professor Hans Joachim Schellnhuber, director of the Potsdam Institute for Climate Impact Research., Germany (2008): “"It is a compromise between ambition and feasibility. A rise of 2^oC could avoid some of the big environmental disasters, but it is still only a compromise…It is a very sweeping argument, but nobody can say for sure that 330ppm is safe. Perhaps it will not matter whether we have 270ppm or 320ppm, but operating well outside the [historic] realm of carbon dioxide concentrations is risky as long as we have not fully understood the relevant feedback mechanisms" [280 ppm is the pre-industrial atmospheric CO₂ concentration]. [22].

4. Part of a statement prepared by Dr Barrie Pittock PSM (former leader, Climate Impact Group, CSIRO, IPCC Lead Author, and author of Climate Change: Turning Up the Heat), and Dr Andrew Glikson (Earth and paleoclimate research scientist, former Principal Research Scientist, AGSO; Visiting Fellow, Australian National University), and endorsed by 40 leading Australian environment scientists: “Australia to make every effort through its own and international actions to prevent CO2 -- equivalent levels from rising above 450 ppm and global warming from rising above 2 degrees C relative to pre-industrial temperatures, as is the European target. Further reduction of CO₂ levels to 300-350 ppm may be required to have a reasonable probability of restoring a safe climate.” [23].

5. Professor Barry Brook (Sir Hubert Wilkins chair of climate change and director of climate science at the University of Adelaide's Environment Institute ): “If the planet is like an oven, it's still possible to turn down the temperature. The number is 300 and the methods will be extraordinary. In 2007, a climate awareness campaign was launched by well-known environmental author Bill McKibben. It was coined 350.org, with the slogan "350 is the most important number on the planet". The figure refers to a target concentration of carbon dioxide (CO2) in the Earth's atmosphere, in parts per million (ppm). This number was drawn from a recent study by a team of climate scientists, led by NASA's Dr James Hansen ... But there is another, more surprising, problem with 350. It's the wrong number. While 350 ppm should give us a reasonable shot at avoiding more than two degrees of warming, that's hardly a safe future to be aiming for. We need only to look at the impacts at less than one degree to know we're already committed to some tough adaptation problems … A target of 300 to 325 ppm CO2 - the levels of the 1950s - is necessary if we wish to cut additional warming and start to roll back the already damaging impacts. As such, 350 is not a target, it's a signpost to a goal. So we're aiming at 350 but the real goal is 300 and we're already at 385”. [24, 25].

6. Australia's premier research organization, the Commonwealth Scientific and Industrial Research Organization (CSIRO), “The Science of Climate Change” (see: http://www.csiro.au/files/files/poqu.pdf ), 2008 : “Since the Industrial Revolution, the CO2 concentrations have risen 37%, methane 150% and nitrous oxide 18%. The global increases in CO2 concentration are due primarily to fossil fuel use and land-use change, while the increases in methane and nitrous oxide are primarily due to agriculture. The CO2 concentration in 2008 of 383 parts per million (ppm) is much higher than the natural range of 172 to 300 ppm that existed over the last 800,000 years.” [26].

7. Dr Graeme Pearman (former CSIRO Climate director; GP Consulting; interim director, MSI; Monash University Sustainaibility Group, Melbourne), “The Earth is deglaciating. Since 1979, more than 20% of the Polar Ice Cap has melted away … Over the last century: global temperatures risen by 0.74 +/- 0.18^oC; 11 of last 12 years rank as amongst the 12 warmest years; snow cover decreased in most regions, especially in spring and summer; summer period extended 12.3 days … Arctic sea-ice decline of 2.7 +/- 0.6 per cent per decade; sea ;levels have risen at a rate of: 1961-2003 1 begin_of_the_skype_highlighting 1961-2003 1 end_of_the_skype_highlighting.9 +/- 0.5 mm yr-1, 1900-2000 1 begin_of_the_skype_highlighting 1900-2000 1 end_of_the_skype_highlighting.7 +/- 0.5 mm yr-1; ocean acidification 0.1 pH unit so far … Gases: current carbon dioxide and methane concentrations far exceed those of the last 600,000 years; increases primarily die to fossil fuel use, agriculture and land-use changes; Warming: unequivocal, evident in air and ocean temperatures, melting of snow and ice and rising sea levels; warming an effect of human activities – at least 5 times greater than that due to solar output change … extreme temperatures – more frequent, intense, longer-lived heat waves … Recent science strongly reinforces the views that: global warming is occurring; it is primarily a result of human activities." [27].

8. Statement by the technical working group on coral, The Royal Society on 6th July 2009: "The Earth’s atmospheric CO₂ level must be returned to less than 350ppm to reverse this escalating ecological crisis and to 320ppm to ensure permanent planetary health. Actions to achieve this must be taken urgently. The commonly mooted best case target of 450ppm and a time frame reaching to 2050 will plunge the Earth into an environmental state that has not occurred in millions of years and from which there will be no recovery for coral reefs and for many other natural systems on which humanity depends. Working group signatories Professor John Veron (Coral Reef Research), Dr Mary Stafford-Smith (Coral Reef Research), Prof. Ove Hoegh-Guldberg (University of Queensland) [and 20 other eminent scientists]". [28].

9. Statement by the World's top climate scientists including Professors James Hansen (US), Hans Joachim Schellnhuber (Germany) , Paul Crutzen (Netherlands Nobel Laureate), in the top scientifc journal Nature that atmospheric CO2 must NOT exceed 350 ppm (September 2009): "Our proposed climate boundary is based on two critical thresholds that separate qualitatively different climate-system states. It has two parameters: atmospheric concentration of carbon dioxide and radiative forcing (the rate of energy change per unit area of the globe as measured at the top of the atmosphere). We propose that human changes to atmospheric CO₂ concentrations should not exceed 350 parts per million by volume, and that radiative forcing should not exceed 1 watt per square metre above pre-industrial levels. Transgressing these boundaries will increase the risk of irreversible climate change, such as the loss of major ice sheets, accelerated sea-level rise and abrupt shifts in forest and agricultural systems. Current CO₂ concentration stands at 387 p.p.m.v. and the change in radiative forcing is 1.5 W m^-2 . " [29].

10. Nobel Peace Prize Laureate Dr Rajendra Pachauri ( U.N.'s top climate scientist, heading the Intergovernmental Panel on Climate Change , IPCC ) (August 2009) : "But as a human being I am fully supportive of that goal [below 350 ppm CO2]. What is happening, and what is likely to happen, convinces me ... [of] moving toward a 350 target". [30].

11. Sir Nicholas Stern (top climate economist, IG Patel Professor of Economics and Government at the London School of Economics, former Chief Economist and Senior Vice-President of the World Bank from 2000 to 2003) (September 2009): “[Re 350 ppm CO2] I think it’s a very sensible long-term target…People have to be aware that is a truly long-term target. We have already passed 350ppm, we are at 390 ppm of CO2 and at 435 ppm of CO2-equivalents right now. It is most important to stop the increase of flows of emissions short term and then start the decline of flows of annual emissions and get them down to levels which will move concentrations of CO2 back down towards 350ppm.” [31].

12. Samuel Fankhauser (economist and climate change specialist at the Grantham Research Institute on Climate Change and the Environment, London School of Economics; member of the UK Committee on Climate Change, a government watchdog that monitors UK climate change policy; former Deputy Chief Economist at the European Bank for Reconstruction and Development (EBRD); served on the 1995, 2001 and 2007 assessments of the Intergovernmental Panel on Climate Change (IPCC)) (2009), was reported by IPS thus: “A future global climate change treaty must limit the concentration of carbon dioxide in the atmosphere to 350 parts per million (ppm), and not 450 ppm, the currently proposed level, Samuel Fankhauser told a meeting of pro-environment legislators from the eight most industrialised countries and emerging economies here. But they felt the goal was not feasible. A British economist and researcher on climate change, Fankhauser said the limit he is urging is the only way to avoid the irreversible bleaching of coral in coastal areas, with all that this implies for people's livelihoods and the environment.”.

Dr Fankhauser was directly quoted thus : “"Action against climate change might cost up to three percent of the world's GDP during the next 40 years," Fankhauser told IPS. "But this price is still cheaper than doing nothing about it…The global climate change sector is already booming. Revenues generated by measures against climate change have surpassed 500 billion dollars in 2008, and could be worth some two trillion dollars by 2020…[500 million people] live within 100 kilometres of reef ecosystems, and benefit from these services…Another important service provided by coral reefs and healthy seashore ecosystems is climate regulation and coastal protection, through carbon sequestration, waste treatment, and protection against hurricanes and the like.” [32].

13. J.E.N. Veron, O. Hoegh-Guldberg, T.M. Lenton, J.M. Lough, D.O. Obura, P. Pearce-Kelly, C.R.C. Sheppard, M. Spalding, M.G. Stafford-Smith and A.D. Rogers (top coral scientists), “The coral reef crisis: the critical importance of <350 ppm CO2”, Marine Pollution Bulletin, October 2009: “Temperature-induced mass coral bleaching causing mortality on a wide geographic scale started when atmospheric CO₂ levels exceeded 320 ppm. When CO₂ levels reached 340 ppm, sporadic but highly destructive mass bleaching occurred in most reefs world-wide, often associated with El Niño events. Recovery was dependent on the vulnerability of individual reef areas and on the reef’s previous history and resilience. At today’s level of 387 ppm, allowing a lag-time of 10 years for sea temperatures to respond, most reefs world-wide are committed to an irreversible decline. Mass bleaching will in future become annual, departing from the 4 to 7 years return-time of El Niño events. Bleaching will be exacerbated by the effects of degraded water-quality and increased severe weather events. In addition, the progressive onset of ocean acidification will cause reduction of coral growth and retardation of the growth of high magnesium calcite-secreting coralline algae.” [33].

14. The president of the Maldive Islands, Mohammed Nasheed, and the Maldive Islands government (at an underwater Cabinet meeting), Resolution, October 2009: “With less than one degree of global warming, the glaciers are melting, the ice sheets collapsing, and low-lying areas are in danger of being swamped. We must unite in a global effort to halt further temperature rises, by slashing carbon dioxide emissions to a safe level of 350 parts per million.’’ [33].

15. Bill McKibben (founder, 350.org, that espouses 24 October, UN Day, as also 350 Day for international action of global warming), 23 October 2009: “Physics and chemistry have already announced their bottom line. In the last two years a slew of research has shown that the most carbon we can safely have in the atmosphere is 350 parts per million - indeed, a NASA team said that above that figure we can’t have “a planet similar to the one on which civilization developed or to which life on earth is adapted.’’ We’re already well past the 350 figure, at 390 parts per million, which is why Arctic sea ice is melting, glaciers thawing, and the ocean turning steadily more acidic. To meet the 350 goal will mean a far more aggressive approach than the one Obama and Congress have so far taken (the bill making its way through Congress explicitly aims for a world with 450 parts per million carbon).” [34].

16. Dr Gideon Polya (Convenor, 300.org, that argues for a return to ~300 ppm CO2), 24 October 2009: "Dear Sir/Madam,

24 October UN Day & 350 Day - Science says reduce CO2 to ~ 300 ppm.

Top climate scientists and the prestigious UK Royal Society say we must DECREASE atmospheric CO2 concentration from the present 390 ppm to 300-350 ppm ASAP for a safe planet for all peoples and all species. [1a, 2a].

Unfortunately, world governments and the pro-coal Australian Liberal-National Party Coalition Opposition and the pro-coal Australian Labor Federal Government (aka the Lib-Labs) want to INCREASE CO2 and other greenhouse gas (GHG) pollution. [3a].

Australia is a world leader in per capita GHG pollution – having 0.3% of world population, its domestic and exported GHG pollution is 3% of world total. Yet optimistic interpretation of official Labor policy indicates that Australia’s domestic and exported GHG pollution will be 119% of the 2000 value by 2020 and 173% by 2050. [4a].

The science-ignoring Australian Lib-Labs (US Rep-Dems) are betraying our children, the Great Barrier Reef, Australia, Humanity and the Biosphere of the Planet. Children should demand that their elders behave responsibly before it is too late and First World-imposed climate genocide destroys 10 billion non-Europeans this century, mostly children.". [5a, 35].

Yours sincerely,

Dr Gideon Polya
Convenor 300.org (see: http://sites.google.com/site/300orgsite/300-org )

17. Catherine Brahic, New Scientist (2007): “Ice cores show that carbon dioxide levels in the atmosphere have remained between 180 and 300 parts per million for the past half-a-million years. In recent centuries, however, CO₂ levels have risen sharply, to at least 380 ppm [2007; 394 ppm in 2011]… So what's going on? It is true that human emissions of CO₂ are small compared with natural sources. But the fact that CO₂ levels have remained steady until very recently shows that natural emissions are usually balanced by natural absorptions. Now slightly more CO₂ must be entering the atmosphere than is being soaked up by carbon "sinks". The consumption of terrestrial vegetation by animals and by microbes (rotting, in other words) emits about 220 gigatonnes of CO₂ every year, while respiration by vegetation emits another 220 Gt. These huge amounts are balanced by the 440 Gt of carbon dioxide absorbed from the atmosphere each year as land plants photosynthesise. Similarly, parts of the oceans release about 330 Gt of CO₂ per year, depending on temperature and rates of photosynthesis by phytoplankton, but other parts usually soak up just as much - and are now soaking up slightly more…Human emissions of CO₂ are now estimated to be 26.4 Gt per year, up from 23.5 Gt in the 1990s, according to the IPCC …Disturbances to the land - through deforestation and agriculture, for instance - also contribute roughly 5.9 Gt per year…Measurements of CO₂ levels over the past 50 years do not show any significant rises after eruptions. Total emissions from volcanoes on land are estimated to average just 0.3 Gt of CO₂ each year.” [36].

[1a]. Johan Rockström, Will Steffen, Kevin Noone, Åsa Persson, F. Stuart Chapin, III, Eric F. Lambin, Timothy M. Lenton, Marten Scheffer, Carl Folke, Hans Joachim Schellnhuber, Björn Nykvist, Cynthia A. de Wit, Terry Hughes, Sander van der Leeuw, Henning Rodhe, Sverker Sörlin, Peter K. Snyder, Robert Costanza, Uno Svedin, Malin Falkenmark, Louise Karlberg, Robert W. Corell, Victoria J. Fabry, James Hansen, Brian Walker, Diana Liverman, Katherine Richardson, Paul Crutzen & Jonathan A. Foley, “A safe operating space for humanity”, Nature, 461, 472-475, 2009: http://www.nature.com/nature/journal/v461/n7263/full/461472a.html .

[2a]. Output of the technical working group meeting, The Royal Society, London, 6th July, 2009, “The Coral Reef Crisis: scientific justification for critical CO2 threshold levels of less than 350ppm” [Working group signatories Professor John Veron (Coral Reef Research), Dr Mary Stafford-Smith (Coral Reef Research), Prof. Ove Hoegh-Guldberg (University of Queensland) and 20 other eminent scientists including Sir David Attenborough FRS (working group co-chair)]: http://www.carbonequity.info/PDFs/The-Coral-Reef-Crisis.pdf .

[3a]. Gideon Polya, “G8 failure means climate genocide for Developing World”, Countercurrents, 11 July 2009: http://www.countercurrents.org/polya110709.htm .

[4a]. Yarra Valley Climate Action Group, “Climate justice and climate injustice: Australia wants a 2020 per capita GHG pollution 15 times greater than Developing World’s”, 2009: http://sites.google.com/site/yarravalleyclimateactiongroup/climate-justice .

[5a]. Gideon Polya, “School war crimes tribunals. Can children save the world’s children?”, MWC News, 8 October 2009: http://mwcnews.net/content/view/33643/42/ . [35].

[1]. Dr Gideon Polya, “How to save the Planet. Accountability, Badge & Credo (ABC Protocol) on MWC News, 14 May 2009: http://mwcnews.net/content/view/30564/42/ ) .

[2]. Dr Andrew Glikson, “The threat to life posed by atmospheric CO2-e over 450 ppm”, submission #34 to the Australian Senate Standing Committee on Economics Inquiry into the Carbon Pollution Reduction Scheme (CPRS), 2009: http://www.aph.gov.au/senate/committee/economics_ctte/cprs_09/submissions/sub34_web.pdf ; see also http://www.aph.gov.au/senate/committee/economics_ctte/cprs_09/submissions/sublist.htm .

[3]. Dr James Hansen (2007), Huge sea level rises are coming – unless we act now”, New Scientist, 2614, 26 July 2007: http://www.newscientist.com/article/mg19526141.600-huge-sea-level-rises-are-coming--unless-we-act-now.html?page=1 .

[4]. Dr John Holdren (2008), “The Science of Climatic Disruption” (power point lecture): http://www.usclimateaction.org/userfiles/JohnHoldren.pdf .

[5]. Dr Gideon Polya (2009), “Global warming, climate emergency” U3A course notes: http://sites.google.com/site/yarravalleyclimateactiongroup/global-warming--global-emergency-course .

[6] David Adam, “World will not meet 2C warming target, climate change experts agree” “, Guardian, 14 April 2009: http://www.guardian.co.uk/environment/2009/apr/14/global-warming-target-2c .

[7]. Gaia Vince (2009), “One last chance to save mankind“, New Scientist, 23 January 2009: http://www.newscientist.com/article/mg20126921.500-one-last-chance-to-save-mankind.html?full=true .

[8]. Dr Gideon Polya, “First World Climate Genocide – global warming to kill 2 billion Indians this century “, Sulekha, 2009: http://gideon.sulekha.com/blog/post/2009/01/first-world-climate-genocide-global-warming-to-kill.htm .

[9]. Yarra Valley Climate Action Group, “Climate Emergency facts and required actions”: http://sites.google.com/site/yarravalleyclimateactiongroup/climate-emergency-facts-and-required-actions .

[10] J. Hansen et al, “Target atmospheric CO2 – where should humanity aim?” : http://arxiv.org/abs/0804.1126 ,

[11]. 350.org: http://www.350.org/mission .

[12]. Greenlivingpedia, “Australian climate Action Summit 2009”: http://www.greenlivingpedia.org/Australian_climate_action_summit_2009 .

[13]. Climate Emergency Network: http://www.climateemergencynetwork.org/ .

[14]. Yarra Valley Climate Action Group: http://sites.google.com/site/yarravalleyclimateactiongroup/Home .

[15]. Links to Dr James Hansen and GISS : http://www.columbia.edu/~jeh1/ ; http://en.wikipedia.org/wiki/James_Hansen ; for 1880-present NASA GISS Global Temperature graphed data see: http://data.giss.nasa.gov/gistemp/ and http://data.giss.nasa.gov/gistemp/graphs/ .

[16]. Climate Code Red: http://www.climatecodered.net/ .

[17]. James Hansen, Mki. Sato, P. Kharecha, G. Russell, D.W. Lea, and M. Siddall, (2007): Climate change and trace gases. Phil. Trans. Royal. Soc. A, 365, 1925-1954: http://pubs.giss.nasa.gov/abstracts/2007/Hansen_etal_2.html .

[18]. Dr James Hansen, to the US National Press Club and a briefing to the US House Select Committee on Energy Independence & Global Warming Congressional Committee: http://www.columbia.edu/~jeh1/2008/TwentyYearsLater_20080623.pdf .

[19]. Hansen, J., Mki. Sato, P. Kharecha, D. Beerling, R. Berner, V. Masson-Delmotte, M. Pagani, M. Raymo, D.L. Royer, and J.C. Zachos, 2008: Target atmospheric CO₂: Where should humanity aim? Open Atmos. Sci. J., 2, 217-231: http://pubs.giss.nasa.gov/abstracts/2008/Hansen_etal.html (abstract) and http://pubs.giss.nasa.gov/docs/2008/2008_Hansen_etal.pdf .

[20]. Dr Andrew Glikson, “The Methane Time Bomb and the Triple Melt-down", Countercurrents, 2009 : http://www.countercurrents.org/glikson101008.htm .

[21]. Wikipedia, “Hans Joachim Schellnhuber”: http://www.pik-potsdam.de/institute/director .

[22]. Professor Hans Joachim Schellnhuber quoted by David Adam, “Roll back time t safeguard climate, expert warns”, Guardian, 15 Septemebr 2008 : http://www.guardian.co.uk/environment/2008/sep/15/climatechange.carbonemissions .

[23]. 350.org, “40 Australian scientists sign on to 350 target, call for urgency oin the fight against climate change”, 22 October 2008: http://www.350.org/en/about/blogs/40-australian-scientists-sign-350-target-call-urgency-fight-against-climate-change .

[24]. Professor Barry Brook, “Six degrees of separation”, Sydney Morning Herald, 23 March 2009: http://www.smh.com.au/environment/earth-hour/six-degrees--of-separation-for-the-planet-20090324-984c.html .

[25]. Professor Barry Brook, “BraveNewClimate.com: http://bravenewclimate.com/ .

[26]. CSIRO, “The Science of Climate Change”, 2008: http://www.csiro.au/files/files/poqu.pdf .

[27]. Dr Graeme Pearman, “Climate change: the evidence, science and current projections”, (2007) (see: http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0011/126569/graeme-pearman-monash-university-namoi-climate-change-forums.pdf ).

[28]. Output of the technical working group meeting, The Royal Society, London, 6th July, 2009, “The Coral Reef Crisis: scientific justification for critical CO₂ threshold levels of less than 350ppm”: http://www.carbonequity.info/PDFs/The-Coral-Reef-Crisis.pdf .

[29]. Johan Rockström, Will Steffen, Kevin Noone, Åsa Persson, F. Stuart Chapin, III, Eric F. Lambin, Timothy M. Lenton, Marten Scheffer, Carl Folke, Hans Joachim Schellnhuber, Björn Nykvist, Cynthia A. de Wit, Terry Hughes, Sander van der Leeuw, Henning Rodhe, Sverker Sörlin, Peter K. Snyder, Robert Costanza, Uno Svedin, Malin Falkenmark, Louise Karlberg, Robert W. Corell, Victoria J. Fabry, James Hansen, Brian Walker, Diana Liverman, Katherine Richardson, Paul Crutzen & Jonathan A. Foley, “A safe operating space for humanity”, Nature, 461, 472-475, 2009: http://www.nature.com/nature/journal/v461/n7263/full/461472a.html .

[30]. Bill McKibben, 350.org, "Pachauri's call for 350ppm is breakthrough moment for climate movement", UK Guardian, 26 August 2009:

http://www.guardian.co.uk/environment/2009/aug/26/pachauri-350ppm-breakthrough-climate .

[31]. Simon Leufstedt, “Nicholas Stern endorses 350 ppm as “a very sensible long-term target””, Green Blog, 12 September 2009: http://www.green-blog.org/2009/09/12/nicholas-stern-endorses-350-ppm-as-a-very-sensible-long-term-target/ .

[32]. Julio Godoy, “Climate change target too ambitious, say lawmakers”, IPS, 26 October 2009: http://www.ipsnews.net/news.asp?idnews=49010 .

[33]. J.E.N. Veron, O. Hoegh-Guldberg, T.M. Lenton, J.M. Lough, D.O. Obura, P. Pearce-Kelly, C.R.C. Sheppard, M. Spalding, M.G. Stafford-Smith and A.D. Rogers, “The coral reef crisis: the critical importance of <350 ppm CO2”, Marine Pollution Bulletin, vol. 58, (10), October 2009, 1428-1436: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V6N-4X9NKG7-3&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1072337698&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=6858c5ff7172f9355068393496a5b35d .

[34]. Bill McKibben, “Mr. Obama, be tough on climate change”, The Boston Globe, 23 October 2009: http://www.boston.com/bostonglobe/editorial_opinion/oped/articles/2009/10/23/mr_obama_be_tough_on_climate_change/ .

[35] Dr Gideon Polya, “Message from Gideon Polya for 350 Day. 24 October UN Day & 350 Day- Science says reduce CO2 to ~ 300 ppm”, coalition for a Safe Climate, safeclimate.org: http://www.safeclimate.org.au/node/188 .

[36]. Catherine Brahic, “Climate myths: human Co2 emissions are too tiny to matter”, New Scientist, 16 May 2007: http://www.newscientist.com/article/dn11638-climate-myths-human-co2-emissions-are-too-tiny-to-matter.html .

Man-made global warming and cyclones

This post is a compendium of recent scientist and science-informed views about the connection between man-made global warming and increased cyclone (hurricane) intensity.

As will become apparent from the quotations below, there have been different views at the cutting edge of research in this area of science (as is normal in science) but a recent international consensus has been established as set out in item #1 (Knutson et al, 2010): “Whether the characteristics of tropical cyclones have changed or will change in a warming climate — and if so, how — has been the subject of considerable investigation, often with conflicting results. Large amplitude fluctuations in the frequency and intensity of tropical cyclones greatly complicate both the detection of long-term trends and their attribution to rising levels of atmospheric greenhouse gases. Trend detection is further impeded by substantial limitations in the availability and quality of global historical records of tropical cyclones. Therefore, it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes. However, future projections based on theory and high-resolution dynamical models consistently indicate that greenhouse warming will cause the globally averaged intensity of tropical cyclones to shift towards stronger storms, with intensity increases of 2–11% by 2100. Existing modelling studies also consistently project decreases in the globally averaged frequency of tropical cyclones, by 6–34%. Balanced against this, higher resolution modelling studies typically project substantial increases in the frequency of the most intense cyclones, and increases of the order of 20% in the precipitation rate within 100 km of the storm centre. For all cyclone parameters, projected changes for individual basins show large variations between different modelling studies.”

1. Thomas R. Knutson, John L. McBride, Johnny Chan, Kerry Emanuel, Greg Holland, Chris Landsea, Isaac Held, James P. Kossin, A. K. Srivastava & Masato Sugi (from the Geophysical Fluid Dynamics Laboratory/NOAA, 201 Forrestal Road, Princeton, New Jersey 08542, USA; Centre for Australian Weather and Climate Research, Melbourne 3001, Australia; Guy Carpenter Asia-Pacific Climate Impact Centre, City University of Hong Kong, Kowloon, Hong Kong, China; Program in Atmospheres, Oceans, and Climate, Massachusetts Institute of Technology, Room 54-1620 MIT, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA; National Center for Atmospheric Research, Boulder, Colorado, USA; National Hurricane Center/NWS/NOAA, 11691 SW 17th Street, Miami, Florida 33165, USA; National Climatic Data Center/NOAA, 1225 W Dayton Street, Madison, Wisconsin 53706, USA; India Meteorological Department, Shivajinagar, Pune 411005, India; and Research Institute for Global Change, JAMSTEC, 3173-25 Showa-machi, Kanazawa-ku, Yokohama, 236-0001 Kanagawa, Japan, respectively): “Whether the characteristics of tropical cyclones have changed or will change in a warming climate — and if so, how — has been the subject of considerable investigation, often with conflicting results. Large amplitude fluctuations in the frequency and intensity of tropical cyclones greatly complicate both the detection of long-term trends and their attribution to rising levels of atmospheric greenhouse gases. Trend detection is further impeded by substantial limitations in the availability and quality of global historical records of tropical cyclones. Therefore, it remains uncertain whether past changes in tropical cyclone activity have exceeded the variability expected from natural causes. However, future projections based on theory and high-resolution dynamical models consistently indicate that greenhouse warming will cause the globally averaged intensity of tropical cyclones to shift towards stronger storms, with intensity increases of 2–11% by 2100. Existing modelling studies also consistently project decreases in the globally averaged frequency of tropical cyclones, by 6–34%. Balanced against this, higher resolution modelling studies typically project substantial increases in the frequency of the most intense cyclones, and increases of the order of 20% in the precipitation rate within 100 km of the storm centre. For all cyclone parameters, projected changes for individual basins show large variations between different modelling studies.” [1].

2. Climate change, MSNBC, commenting on Knutson et al (2010) (item #1): “Top researchers now agree that the world is likely to get stronger but fewer hurricanes in the future because of global warming, seeming to settle a scientific debate on the subject. But they say there's not enough evidence yet to tell whether that effect has already begun. Since just before Hurricane Katrina hit Louisiana and Mississippi in 2005, dueling scientific papers have clashed about whether global warming is worsening hurricanes and will do so in the future. The new study seems to split the difference. A special World Meteorological Organization panel of 10 experts in both hurricanes and climate change — including leading scientists from both sides — came up with a consensus, which is published online Sunday in the journal Nature Geoscience… The study offers projections for tropical cyclones worldwide by the end of this century, and some experts said the bad news outweighs the good. Overall strength of storms as measured in wind speed would rise by 2 to 11 percent, but there would be between 6 and 34 percent fewer storms in number. Essentially, there would be fewer weak and moderate storms and more of the big damaging ones, which also are projected to be stronger due to warming… An 11 percent increase in wind speed translates to roughly a 60 percent increase in damage… The storms also would carry more rain, another indicator of damage… study suggests category 4 and 5 Atlantic hurricanes — those with winds more than 130 mph — would nearly double by the end of the century.” [2].

3. Greg Holland ( National Center for Atmospheric Research in Colorado) and Peter Webster (Georgia Institute of Technology)(2007): “We find that long-period variations in tropical cyclone and hurricane frequency over the past century in the North Atlantic Ocean have occurred as three relatively stable regimes separated by sharp transitions. Each regime has seen 50% more cyclones and hurricanes than the previous regime and is associated with a distinct range of sea surface temperatures (SSTs) in the eastern Atlantic Ocean. Overall, there appears to have been a substantial 100-year trend leading to related increases of over 0.7°C in SST and over 100% in tropical cyclone and hurricane numbers. It is concluded that the overall trend in SSTs, and tropical cyclone and hurricane numbers is substantially influenced by greenhouse warming. Superimposed on the evolving tropical cyclone and hurricane climatology is a completely independent oscillation manifested in the proportions of tropical cyclones that become major and minor hurricanes. This characteristic has no distinguishable net trend and appears to be associated with concomitant variations in the proportion of equatorial and higher latitude hurricane developments, perhaps arising from internal oscillations of the climate system. The period of enhanced major hurricane activity during 1945–1964 is consistent with a peak period in major hurricane proportions.” [3].

4. US Today, commenting on Holland and Webster (2007) (item #3) [with a graph of number of North Atlantic hurricanes per year versus time from 1850 to 2007]): “The number of hurricanes that develop each year has more than doubled over the past century, an increase tied to global warming, according to a study released Sunday."We're seeing a quite substantial increase in hurricanes over the last century, very closely related to increases in sea-surface temperatures in the tropical Atlantic Ocean," says study author Greg Holland of the National Center for Atmospheric Research in Colorado. Working with hurricane researcher Peter Webster of Georgia Institute of Technology, Holland looked at sea records from 1855 to 2005 in a study published in the British journal Philosophical Transactions of the Royal Society A. The researchers found that average hurricane numbers jumped sharply during the 20th century, from 3.5 per year in the first 30 years to 8.4 in the earliest years of the 21st century. Over that time, Atlantic Ocean surface temperatures increased .65 degrees, which experts call a significant increase… The new study drew criticism from experts who dispute the merits of combining data from the late 19th and early 20th centuries, when hurricane-tracking satellites didn't exist, with statistics gleaned from more modern technology.” [4].

5. Dr Andrew Ash (director, CSIRO’s Climate Adaptation Flagship) re climate change, floods and cyclones (2011): “We have had stronger cyclones in history and we have had cyclones just as large in size, but it is rare to get both a very large and intense cyclone. The flooding we have experienced to date on the whole has been within the bounds of historical events though in some areas, such as the Western Downs in Queensland and parts of Victoria, all time records have been broken. While extreme events like flooding and cyclones are an expected feature of La Nina events, the oceans around eastern and northern Australia are particularly warm at present. It is usual for the ocean in the Western Pacific to be warm during a La Nina event but the ocean temperatures are currently the highest on record…[In December 2010 the Southern Oscillation Index, a measure of the extent of La Nina, recorded a level of 27.1... the highest recorded December value in history] … The record warm temperatures are most likely a combination of La Nina and additional warming from human activities. While the flooding events and cyclones experienced this year aren't caused by climate change, the record warm ocean temperatures provide conditions more conducive to exacerbating these naturally occurring events associated with La Nina." [5].

6. Professor Tim Flannery (mammalogist, palaeontologist, environmentalist and 2007 Australian of the Year) re climate change, floods and cyclones (2011): “The individual severe weather events you point to are the kind of thing climate modelling predicts will become more frequent as greenhouse gas concentrations increase.” [5].

7. Australian Bureau of Meteorology (2006) re Tropical cyclones and climate change: “Leading scientists provide an expert view of the current state of knowledge. They note that there has been a high level of interest in the topic and that substantial debate is still occurring within the scientific community. With regard to the recent tropical cyclone seasons they conclude: "No single high impact tropical cyclone event of 2004 and 2005 can be directly attributed to global warming, though there may be an impact on the group as a whole.” Dr Geoff Love, the Australian Director of Meteorology, has submitted to the World Meteorological Organization's Commission for Atmospheric Sciences, meeting in Cape Town, South Africa, a "Statement on Tropical Cyclones and Climate Change". The Statement was prepared by an expert group of scientists comprising Dr John McBride and Dr Jeff Kepert of the Bureau of Meteorology in Australia, Professor Johnny Chan of China, Julian Heming of the UK, and Dr Greg Holland, Professor Kerry Emanuel, Thomas Knutson, Dr Hugh Willoughby and Dr Chris Landsea of the US. The paper reaffirms the finding of a 1998 study saying that any change in the frequency of tropical cyclones (hurricanes/typhoons) due to climate change cannot be determined due to a lack of knowledge and limitations of the available observing technologies. The little evidence that does exist indicates little or no change in global frequency. It also says that while some recent studies have suggested the intensity of tropical cyclones (hurricanes/typhoons) has increased substantially over the past 50 years due to climate change, the scientific community is "deeply divided". Some researchers believe the climate record is too inconsistent to draw such a conclusion due to changes in observations equipment and methods over time. The panel says it cannot come to a definitive conclusion in this "hotly debated area"… No single disaster caused by a tropical cyclone (hurricane/typhoon) in 2004 or 2005 - including Hurricane Katrina in the US - can be directly attributed to global warming. Rather, climate change may have an impact on the group as a whole. Further research is needed.” [6, 7].

8. Dr John McBride and Dr Jeff Kepert ( Bureau of Meteorology in Australia), Professor Johnny Chan (China), Julian Heming (UK), and Dr Greg Holland, Professor Kerry Emanuel, Thomas Knutson, Dr Hugh Willoughby and Dr Chris Landsea (US), “Statement on Tropical Cyclones and Climate Change" (2006): “No single high impact tropical cyclone event of 2004 and 2005 can be directly attributed to global warming, though there may be an impact on the group as a whole; Emanuel (2005) has produced evidence for a substantial increase in the power of tropical cyclones (denoted by the integral of the cube of the maximum winds over time) over the last 50 years. This result is supported by the findings of Webster et al (2005) that there has been a substantial global increase (nearly 100%) in the proportion of the most severe tropical cyclones (category 4 and 5 on the Saffir-Simpson scale), from the period from 1970 to 10995, which has been accompanied by a similar decrease in weaker systems. The research community is deeply divided over whether the results of these studies are due, at least in part, to problems in the tropical cyclone data base. Precisely, the historical record of tropical cyclone tracks and intensities is a product of real-time operations. Thus its accuracy and completeness changes continuously through the record as a result of the continuous changes and improvements in data density and quality, changes in satellite remote sensing retrieval and dissemination, and changes in training. In particular a step-function change in methodologies for determination of satellite intensity occurred with introduction of geosynchronous satellites in the mid to late 1970s. The division of the community on the Webster et al and Emanuel papers is not as to whether Global warming can cause a trend in tropical cyclone intensities. Rather it is on whether such a signal can be can be detected in the historical data base.” [6, 7, 8].

9. Quirin Schiermeier (writer for Nature, cartographer, graduate in geography, statistics and economics from the University of Munich) on global warming and hurricane intensity (2008): “As this year's Atlantic hurricane season becomes ever more violent, scientists have come up with the firmest evidence so far that global warming will significantly increase the intensity of the most extreme storms worldwide. The maximum wind speeds of the strongest tropical cyclones have increased significantly since 1981, according to research published in Nature this week [see #]. And the upward trend, thought to be driven by rising ocean temperatures, is unlikely to stop at any time soon… One of the most contentious issues in the climate-change debate has been whether the strength, number and duration of tropical cyclones will increase in a warmer world. Basic physics and modelling studies do suggest that tropical storms will become more intense, because warmer oceans provide more energy that can be converted into cyclone wind. But others believe that atmospheric changes might have an inhibiting role. Increasing shearing winds - another predicted consequence of global warming - are thought to suppress the cyclonic rotation of the storms, for example… The team statistically analysed satellite-derived data of cyclone wind speeds. Although there was hardly any increase in the average number or intensity of all storms, the team found a significant shift in distribution towards stronger storms that wreak the greatest havoc. This meant that, overall, there were more storms with a maximum wind speed exceeding 210 kilometres per hour (category 4 and 5 storms on the Saffir–Simpson scale). Rising ocean temperatures are thought to be the main cause of the observed shift. The team calculates that a 1 ºC increase in sea-surface temperatures would result in a 31% increase in the global frequency of category 4 and 5 storms per year: from 13 of those storms to 17. Since 1970, the tropical oceans have warmed on average by around 0.5 ºC. Computer models suggest they may warm by a further 2 ºC by 2100.” [9].

10. Elsner, J., Kossin, J. P. & Jagger, T. H. on global warming and increased tropical cyclone intensity (2008): “Atlantic tropical cyclones are getting stronger on average, with a 30-year trend that has been related to an increase in ocean temperatures over the Atlantic Ocean and elsewhere. Over the rest of the tropics, however, possible trends in tropical cyclone intensity are less obvious, owing to the unreliability and incompleteness of the observational record and to a restricted focus, in previous trend analyses, on changes in average intensity. Here we overcome these two limitations by examining trends in the upper quantiles of per-cyclone maximum wind speeds (that is, the maximum intensities that cyclones achieve during their lifetimes), estimated from homogeneous data derived from an archive of satellite records. We find significant upward trends for wind speed quantiles above the 70th percentile, with trends as high as 0.3±0.09ms^-1yr^-1 (s.e.) for the strongest cyclones. We note separate upward trends in the estimated lifetime-maximum wind speeds of the very strongest tropical cyclones (99th percentile) over each ocean basin, with the largest increase at this quantile occurring over the North Atlantic, although not all basins show statistically significant increases. Our results are qualitatively consistent with the hypothesis that as the seas warm, the ocean has more energy to convert to tropical cyclone wind.” [10].

11. Mark A. Saunders and Adam S. Lea (Benfield UCL Hazard Research Centre, Department of Space and Climate Physics, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK) on sea surface warming and increased Atlantic hurricane activity (2009): “Atlantic hurricane activity has increased significantly since 1995, but the underlying causes of this increase remain uncertain. It is widely thought that rising Atlantic sea surface temperatures have had a role in this^{16, 17}, but the magnitude of this contribution is not known. Here we quantify this contribution for storms that formed in the tropical North Atlantic, Caribbean Sea and Gulf of Mexico; these regions together account for most of the hurricanes that make landfall in the United States. We show that a statistical model based on two environmental variables—local sea surface temperature and an atmospheric wind field—can replicate a large proportion of the variance in tropical Atlantic hurricane frequency and activity between 1965 and 2005. We then remove the influence of the atmospheric wind field to assess the contribution of sea surface temperature. Our results indicate that the sensitivity of tropical Atlantic hurricane activity to August–September sea surface temperature over the period we consider is such that a 0.5°C increase in sea surface temperature is associated with a ~40% increase in hurricane frequency and activity. The results also indicate that local sea surface warming was responsible for ~40% of the increase in hurricane activity relative to the 1950–2000 average between 1996 and 2005. Our analysis does not identify whether warming induced by greenhouse gases contributed to the increase in hurricane activity, but the ability of climate models to reproduce the observed relationship between hurricanes and sea surface temperature will serve as a useful means of assessing whether they are likely to provide reliable projections of future changes in Atlantic hurricane activity.” [11].

12. Webster, P. J., Holland, G. J., Curry, J. A. & Chang, H.-R. on changes in tropical cyclone number, duration, and intensity in a warming environment (2005): “We examined the number of tropical cyclones and cyclone days as well as tropical cyclone intensity over the past 35 years, in an environment of increasing sea surface temperature. A large increase was seen in the number and proportion of hurricanes reaching categories 4 and 5. The largest increase occurred in the North Pacific, Indian, and Southwest Pacific Oceans, and the smallest percentage increase occurred in the North Atlantic Ocean. These increases have taken place while the number of cyclones and cyclone days has decreased in all basins except the North Atlantic during the past decade… We conclude that global data indicate a 30-year trend toward more frequent and intense hurricanes, corroborated by the results of the recent regional assessment. This trend is not inconsistent with recent climate model simulations that a doubling of CO₂ may increase the frequency of the most intense cyclones, although attribution of the 30-year trends to global warming would require a longer global data record and, especially, a deeper understanding of the role of hurricanes in the general circulation of the atmosphere and ocean, even in the present climate state.” [12].

13. Professor Kerry Emanuel (Program in Atmospheres, Oceans, and Climate, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA) on warming and increased cyclone intensity (2005): “Theory and modelling predict that hurricane intensity should increase with increasing global mean temperatures, but work on the detection of trends in hurricane activity has focused mostly on their frequency and shows no trend. Here I define an index of the potential destructiveness of hurricanes based on the total dissipation of power, integrated over the lifetime of the cyclone, and show that this index has increased markedly since the mid-1970s. This trend is due to both longer storm lifetimes and greater storm intensities. I find that the record of net hurricane power dissipation is highly correlated with tropical sea surface temperature, reflecting well-documented climate signals, including multi-decadal oscillations in the North Atlantic and North Pacific, and global warming. My results suggest that future warming may lead to an upward trend in tropical cyclone destructive potential, and—taking into account an increasing coastal population—a substantial increase in hurricane-related losses in the twenty-first century.” [13].

14. Professor Kerry Emanuel, Ragoth Sundararajan, and John Williams (Program in Atmospheres, Oceans, and Climate, Massachusetts Institute of Technology, Cambridge, Massachusetts} on modeling showing cyclone storm intensity generally increases with global warming (2008): “Changes in tropical cyclone activity are among the more potentially consequential results of global climate change, and it is therefore of considerable interest to understand how anthropogenic climate change may affect such storms. Global climate models are currently used to estimate future climate change, but the current generation of models lacks the horizontal resolution necessary to resolve the intense inner core of tropical cyclones. Here we review a new technique for inferring tropical cyclone climatology from the output of global models, extend it to predict genesis climatologies (rather than relying on historical climatology), and apply it to current and future climate states simulated by a suite of global models developed in support of the most recent Intergovernmental Panel on Climate Change report. This new technique attacks the horizontal resolution problem by using a specialized, coupled ocean–atmosphere hurricane model phrased in angular momentum coordinates, which provide a high resolution of the core at low cost. This model is run along each of 2,000 storm tracks generated using an advection-and-beta model, which is, in turn, driven by large-scale winds derived from the global models. In an extension to this method, tracks are initiated by randomly seeding large areas of the tropics with weak vortices and then allowing the intensity model to determine their survival, based on large-scale environmental conditions. We show that this method is largely successful in reproducing the observed seasonal cycle and interannual variability of tropical cyclones in the present climate, and that it is more modestly successful in simulating their spatial distribution. When applied to simulations of global climate with double the present concentration of carbon dioxide, this method predicts substantial changes and geographic shifts in tropical cyclone activity, but with much variation among the global climate models used. Basinwide power dissipation and storm intensity generally increase with global warming, but the results vary from model to model and from basin to basin. Storm frequency decreases in the Southern Hemisphere and north Indian Ocean, increases in the western North Pacific, and is indeterminate elsewhere. We demonstrate that in these simulations, the change in tropical cyclone activity is greatly influenced by the increasing difference between the moist entropy of the boundary layer and that of the middle troposphere as the climate warms.” [14].

15. Professor Ross Garnaut (climate change economist and Australian Federal Government climate change adviser) warning that floods and cyclones like those experienced by Australian in 2011 will get more extreme as global warming increases (2011): “[while climate change cannot be directly blamed for the recent flooding, or for Cyclone Yasi] the greater energy in the atmosphere and the seas can intensify extreme events and I'm afraid that we're feeling some of that today, and we're feeling that at a time when global warming is in its early stages… [re carbon tax and climate change action] "Getting back in the saddle, I would like a result this time… We've taught ourselves that we're capable of making quite a big mess of dealing with this diabolical policy problem, I hope we've learnt something along the way…We haven't played our proportionate part amongst developed countries so far. We've talked about it from time to time, but we haven't done much…It will be quite important for the international effort that Australia ceases to be a drag on the international effort…I'm not talking about us leading the world, I'm talking about our catching up." [15].

16. Parliament of Australia, Parliamentary Library (that provides carefully researched infomation to members of the Australian Federal Parliament) : “Are extreme weather events—severe storms, flooding, droughts, heat waves or extremely violent cyclones—becoming more common? The answer appears to be 'yes'. Trends towards more powerful storms and hotter, longer dry periods have been observed, according to the IPCC's Fourth Assessment Report, and this trend is projected to continue.” [16].

17. Professor John Holdren (Professor of Environmental Policy at the Kennedy School of Government at Harvard University; Director of the Woods Hole Research Center; recent Chairman of the American Association for the Advancement of Science and President Obama’s chief scientific adviser) on climatic disruption (2008): “Harm is already occurring (continued). (Figure) Total power released by tropical cyclones (green: Annual mean HADISST 30S-30N) has increased (circa 2-fold 1990-2003) along with sea surface temperatures (blue: West Pac + East Pac + Atlantic); Kerry Emanuel, MIT, 2006”. [17].

18. Professor Vicky Pope (head of climate change advice at the Met Office, UK) explains how a warmer world is a wetter world (2011): "As the average global temperature increases one would expect the moisture content of the atmosphere to rise, due to more evaporation from the sea surface. For every 1C sea surface temperature rise, atmospheric moisture over the oceans increases by 6-8%. Also in general, as more energy and moisture is put into the atmosphere [by warming], the likelihood of storms, hurricanes and tornadoes increases." [18].

19. Dr Andrew Glikson (former Principal Research Scientist, Australian Geological Survey Organization, Earth and paleoclimate scientist. School of Archaeology and Anthropology, Research School of Earth Science, Planetary Science Institute, Australian National University) on Queensland floods [noting according to the report, that climate scientists were careful never to point to a single event as evidence of climate change but to examine medium and long-term trends] : “'Cyclones have increased twofold over the past 20 years. Floods have increased threefold. It's happening now, and it's happening faster than some of the climate-change scientists have dared to predict” [19].

20. William Cosgrove (vice president, World Water Council), 3rd World Water Forum, 2003: "Extreme weather records are [already] being broken every year and the resulting hydro-meteorological disasters claim thousands of lives and disrupt national economies," said of the Marseille-based think tank made up of users and suppliers of water for social and economic development. The big problem is that most countries aren't ready to deal adequately with the severe natural disasters that we get now, a situation that will become much worse as storms and droughts become more pervasive. Ignoring the problem is no longer an option… The increasing incidence of extreme events provides a convincing argument to continue looking into building partnerships between science, water managers and the disaster preparedness communities, including the development and dissemination of capacity development packages and methodologies. It is telling that disaster reduction has been recognized since 2000 an issue central to poverty reduction. ” [20, 21].

21. World Water Council press release from the 3rd World Water Forum re climate change, droughts and floods (February 2003): “Economic loses from weather and flood catastrophes have increased ten-fold over the past 50 years, partially the result of rapid climate changes, the World Water Council (WWC) says. These rapid climate changes are seen in more intense rainy seasons, longer dry seasons, stronger storms, shifts in rainfall and rising sea levels,. More disastrous floods and droughts have been the most visible manifestations of these changes. From 1971 to 1995, floods affected more than 1.5 billion people worldwide, or 100 million people per year, according to experts. This total includes 318,000 killed, and more than 81 million left homeless. Major floods that left at least 1,000 people dead and caused $1 billion in damages per episode have been the most destructive… According to climate experts, the expected climatic change during the 21st century will further intensify the hydrological cycle – with rainy seasons becoming shorter and more intense in some regions, while droughts in other areas will grow longer in duration, which could endanger species and crops and lead to drops in food production globally. Evidence for the link between climate change and increasing climate variability is mounting rapidly. For example, scientific research has linked the recent droughts in the USA and Afghanistan to the effects of global warming… These climate disasters stemming from climate variability include: Floods [and Droughts] - Based on data for ther period 1950 to 1998, the number of major flood disasters has grown considerably world-wide from decade to decade – six cases in the 1950s, seven in the 1960s, eight in the 1970s, 18 in the 1980s, and 26 in the 1990s. The number of significant flood disasters in the 1990s was higher than in the three previous decades combined. Overall, global precipitation is estimated to have increased by about two percent since 1900, though not on a uniform basis. This disparity in new rainfall caused some places to become wetter and others to get drier, such as North Africa south of the Sahara. In the most calamitous storm surge, the flood in Bangladesh in April 1991 killed 141,000 people. Two floods in China, one in 1996 and the second in 1998, caused the highest material losses of the decade, of the order of $30 billion and $26.5 billion, respectively. Floods also destroy the hard-won economic advances that many in the developing world have accomplished, such as the Mozambique floods of 2000, which left nearly 1 million homeless, and Hurricane Mitch in Central America [1998]. Comparing the economic impacts of the 2000 flood in Mozambique with the 2002 flood in Central Europe clearly illustrates the disparity in how national economies are impacted by extreme events. The cost of damages reflects the income levels of the countries. According to officials at the World Bank, the Mozambique flood resulted in a 45 percent drop in GDP in 2000, whereas in Germany, the 2002 flood is estimated to have caused less than a one percent drop in GDP…Hurricane Mitch [1998] killed 11,000 people, with thousands of others missing. More than 3 million people were either homeless or severely affected. In this extremely poor regions, estimates of the total damage from the storm surpassed $5 billion. The President of Honduras, Carlos Flores Facusse, claimed the storm destroyed 50 years of progress. As far as the geographic distribution of the worst floods, the majority occurred in Asian countries … In addition, the impact of floods has had increasingly detrimental and disruptive effects on human health. In flooded areas, some diseases such as diarrhea, which kills 2.2 million children under th4 age of five per year, or leptospirosis (a systemic infection that can lead to meningitis and hemorrhagic jaundice) spread more rapidly… Many countries in Africa have been suffering from unprecedented droughts that may signal widespread climate change … Sea level rise is a concern in coastal and low-lying areas, including small islands. In addition to coastal flooding, saltwater intrusion into freshwater aquifers present a threat to water supplies. The average global sea level rise from 1900 to the year 2100 is expected to be 0.48 meters (19 inches), between twice and four times the rate of rise over the 20th century. The main effect on humans will be to confront extreme events such as storm surges. Areas of greatest danger include Small islands in the Pacific, mainly the Atolls; Coastal low-lying countries like Bangladesh and the Netherlands; Coastal mega-cities like Tokyo, Lagos, Buenos Aires and New York.” [20, 21].

22. Global Greenhouse Warming.com on climate and floods: "Meteorologic floods are by far the most common of the types of floods in the human experience, affecting parts of the globe every year. Such floods can bring good, such as the fertile soils formerly brought to the Nile Delta by annual flooding. However, large floods are mostly known for their catastrophic loss of life and property, such as in China and Bangladesh which repeatedly devastated by floods - Bangladesh lost 300,000 people in November 1970 and more than 130,000 in April 1991, from cyclone-induced flooding, and the massive flooding of the Yangtze River in China in 1931 caused more than 3 million deaths with a further 2 million in 1959 from flooding and starvation. …By 2025, half the world's population will be living in areas that are at risk from storms and other weather extremes," the World Water Council said, citing evidence gathered by U.N. and other experts. The economic cost of changes in climate and floods will be huge, especially for poor countries that are likely to bear the brunt of these events. The phrase Climate and Floods is something we will hear more of in the years ahead.”[22].

23. Dr James Hansen in “Storms of My Grandchildren” (2010): “Global warming does increase the intensity of droughts and heat waves, and thus the area of forest fires. However, because a warmer atmosphere holds more water vapour, global warming must also increase the intensity of the other extreme of the hydrological cycle – meaning heavier rains, more extreme floods, and more intense storms driven by latent heat, including thunderstorms, tornadoes, and tropical storms. I realized that I should have emphasized more strongly [in his 1988 testimony to a US Senate Committee] that both extremes increase with global warming.” [23].

24. American Association for the Advancement of Science (AAAS), 2006 (founded in 1848, AAAS serves some 262 affiliated societies and academies of science, serving 10 million individuals; the AAAS journal Science has the largest paid circulation of any peer-reviewed general science journal in the world, with an estimated total readership of 1 million): “The scientific evidence is clear: global climate change caused by human activities is occurring now, and it is a growing threat to society. Accumulating data from across the globe reveal a wide array of effects: rapidly melting glaciers, destabilization of major ice sheets, increases in extreme weather, rising sea level, shifts in species ranges, and more. The pace of change and the evidence of harm have increased markedly over the last five years. The time to control greenhouse gas emissions is now… In addition to rapidly reducing greenhouse gas emissions, it is essential that we develop strategies to adapt to ongoing changes and make communities more resilient to future changes. The growing torrent of information presents a clear message: we are already experiencing global climate change. It is time to muster the political will for concerted action. Stronger leadership at all levels is needed. The time is now. We must rise to the challenge. We owe this to future generations.” [24].

25. Senator Christine Milne (Australian Greens deputy leader; Tasmanian Greens senator) on man-made climate change and Cyclone Yasi (2011): “This is a tragedy, but it is a tragedy of climate change. The scientists have been saying that we are going to experience more extreme weather events, that their intensity is going to increase, their frequency.” [25]

References.

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[2]. Climate change, MSNBC, “Study: stronger hurricanes loom. Fewer expected but bigger storms to bring more damage”, commenting on Knutson et al (2010), Climate change, MSNBC, 21 February 2010: http://www.msnbc.msn.com/id/35506750/ns/us_news-environment/ .

[3]. Greg Holland and Peter Webster, “Heightened tropical cyclone activity in the North Atlantic: natural variability or climate trend?”, Philosophical Transactions of the Royal Society A, vol. 365, no. 1860. pp 2695-2716, 2007: http://rsta.royalsocietypublishing.org/content/365/1860/2695.short .

[4]. US Today, “Study links more hurricanes, climate change”, 30 July 2007: http://www.usatoday.com/weather/hurricane/2007-07-29-more-hurricanes_N.htm .

[5]. Matt Granfield, “Coincidence or climate change?’, ABC Drum Unleashed, 3 February 2011: http://www.abc.net.au/unleashed/43560.html .

[6]. Australian Bureau of Meteorology, “Tropical cyclones and climate change”, media release, 20 February 2006: http://www.bom.gov.au/announcements/media_releases/ho/20060220.shtml .

[7]. Dr John McBride and Dr Jeff Kepert ( Bureau of Meteorology in Australia), Professor Johnny Chan (China), Julian Heming (UK), and Dr Greg Holland, Professor Kerry Emanuel, Thomas Knutson, Dr Hugh Willoughby and Dr Chris Landsea (US), “Statement on Tropical Cyclones and Climate Change", submitted to the World Meteorological Organization's Commission for Atmospheric Sciences, meeting in Cape Town, South Africa by Dr Geoff Love ( Australian Director of Meteorology), 2006: http://www.bom.gov.au/info/CAS-statement.pdf .

[8]. Tropical cyclone, subsection Global warming, Wikipedia: http://webcache.googleusercontent.com/search?q=cache:41B86CUK98wJ:en.wikipedia.org/wiki/Tropical_cyclone+%22tropical+cyclones+and+climate+change%22&cd=4&hl=en&ct=clnk&gl=au&source=www.google.com.au .

[9]. Quirin Schiermieier, “Hurricanes are getting fiercer. Global warming blamed for growth in storm intensity”, Nature News, 3 September 2008: http://www.nature.com/news/2008/080903/full/news.2008.1079.html .

[10]. Elsner, J., Kossin, J. P. & Jagger, T. H., “The increasing intensity of the strongest tropical cyclones”, Nature 445, 92–95 (2008): http://www.nature.com/nature/journal/v455/n7209/full/nature07234.html .

[11]. Mark A. Saunders and Adam S. Lea, “Large contribution of sea surface warming to recent increase in Atlantic hurricane activity”, Nature, vol 451, pp 557-560, 2008: http://www.nature.com/nature/journal/v451/n7178/full/nature06422.html .

[12]. Webster, P. J., Holland, G. J., Curry, J. A. & Chang, H.-R., “Changes in tropical cyclone number, duration, and intensity in a warming environment. ” Science 309, 1844–1846 (2005): http://www.sciencemag.org/content/309/5742/1844.full .

[13] Kerry Emanuel, “Increasing destructiveness of tropical cyclones over the past 30 years”. Nature vol. 436, pp686-688, 2005: http://www.nature.com/nature/journal/v436/n7051/abs/nature03906.html .

[14]. Kerry Emanuel, Ragoth Sundararajan, and John Williams, “Hurricanes and Global Warming: Results from Downscaling IPCC AR4 Simulations”, Bull. Amer. Meteor. Soc., vol. 89, pp347–367, 2008: http://journals.ametsoc.org/doi/abs/10.1175/BAMS-89-3-347 .

[15]. Professor Ross Garnaut quoited in “Cyclones, floods to get worse as warming increases: Garnaut”, ABC News, 3 February 2011: http://www.abc.net.au/news/stories/2011/02/03/3129424.htm .

[16]. Parliament of Australia, Parliamentary Library, “More extreme weather”: http://www.aph.gov.au/library/pubs/ClimateChange/theClimate/moreExtreme.htm .

[17]. Dr John Holdren (2008), “The Science of Climatic Disruption” (power point lecture): http://www.usclimateaction.org/userfiles/JohnHoldren.pdf .

[18]. Vicky Pope, quoted in Damien Carrington, “”Australian floods: La Nina to blame”, Guardian, 11 January 2011: http://www.guardian.co.uk/environment/2011/jan/11/australia-floods-la-nina .

[19]. Karen Kissane, “Disaster expert urges a retreat from the coast”, The Age, 15 January 2011: http://www.theage.com.au/national/disaster-expert-urges-a-retreat-from-the-coast-20110114-19rcg.html .

[20]. World Water Council 3rd World Water Forum, Press release, 27 February 2003: http://www.worldwatercouncil.org/fileadmin/wwc/News/WWC_News/News_2003/PR_climate_27.02.03.pdf .

[21]. “Climate change boosting floods, drought: experts”, News in Science, 3 March 2003: http://www.abc.net.au/science/news/stories/s796319.htm .

[22]. Global Greenhouse Warming.com, “Climate and floods” (2003): http://www.global-greenhouse-warming.com/climate-and-floods.html .

[23]. James Hansen, “Storms of My Grandchildren. The truth about the coming climate catastrophe and our last chance to save humanity”, Bloomsbury, London, 2009, pxv.

[24]. American Association for the Advancement of Science (AAAS), AAAS Resolution: Statement on Climate Change”, 2006: http://archives.aaas.org/docs/resolutions.php?doc_id=447 .

[25]. “TC Yasi caused by climate change: Greens”, ABC News, 1 February 2011: http://www.abc.net.au/news/stories/2011/02/01/3127184.htm .