Abstract of a paper delivered by Clive Hamilton to the Royal Society of the Arts last night in Sydney:
Recent analysis of carbon budgets shows that the timing and scale of emission reductions needed to avert dangerous climate change are well beyond any national policy proposals or anticipated international agreement.
There have been two alarming developments in recent years. First, climate scientists are reporting that the scale of damages associated with warming of 2°C is much worse than previously believed, suggesting that more stringent emission cuts are essential.
Secondly, global growth in greenhouse gas emissions is much higher than anticipated a few years ago and the world is now on a warming path that is worse than the worst-case scenario. Rather than decarbonising, the world is carbonising at an unprecedented rate.
Analysis reviewed in this paper shows that, under the most optimistic assumptions about the timing and extent of global greenhouse gas emission reductions, cumulative emissions over the next few decades will result in atmospheric concentrations reaching 650 ppm of CO2-e, associated with warming of 4°C or more before the end of the century, a temperature not seen on Earth for 15 million years.
It now seems almost certain that, if it has not occurred already, within the next several years enough warming will be locked into the system to set in train positive feedback processes that will overwhelm any attempts to cut back on carbon emissions. Humans will be powerless to stop the shift to a new climate on Earth, one much less sympathetic to life.
Read the full paper here.
Clive’s paper is based on the most up-to-date climate science, reported recently in Oxford meeting of leading climate scientists (28-30 October, 09).
(http://www.eci.ox.ac.uk/4degrees/programme.php)
A summary is appended below:
THE RISE OF ATMOSPHERIC CO2 ABOVE 350 PPM AT THE CURRENT RATE OF ABOUT 2 PPM/YEAR IS TRANSCENDING THE CONDITIONS THAT ALLOWED THE DEVELOPMENT OF HUMAN AGRICULTURE AND CIVILIZATION FROM ABOUT 8000 YEARS AGO.
Life on Earth depends on a delicate balance between the atmosphere, the oceans and the biosphere. The atmosphere acts like the “lungs” of the biosphere, while the ocean currents act as its “vein system”, modulating temperatures around the globe. Changes to the chemistry of the atmosphere, including greenhouse gases (CO2, methane, nitric oxides, ozone) and aerosols (mainly sulphur dioxide) through Earth’s history resulted in climate shifts between greenhouse states and glacial/interglacial states. Such changes were triggered by orbital shifts, solar cycles, volcanic events, asteroid impacts, release of methane from sediments and, on longer time scales, the distribution of oceans, continents and mountain ranges.
Sharp decline in CO2 34 million years ago and 15 million years ago to below 500 ppm has resulted in the development of the Antarctic ice sheet. About 2.8 million years ago a further decline in CO2 resulted in formation of the Greenland ice sheet and Arctic Sea ice. The current runaway climate change is a direct result of human emissions and land clearing. The emission of more than 320 billion tons of carbon (over 50% the original atmospheric inventory) since 1750 raised CO2 levels from 280 to 388 ppm, or 460 ppm CO2-equivalent (a value including the effect of methane).
Acceleration of climate change since the mid-1970s is leading toward a global temperature rise of +1.5oC above pre-industrial time, once the masking effects of sulphur aerosols are removed. The polar regions have already warmed by up to 4oC. This results in carbon cycle and ice/water melt feedback processes, with consequent (A) extreme rates of polar ice melting, including the Arctic Sea, Greenland, West and East Antarctica, which threatens accelerated sea level rise above the current rate of 0.35 cm/year; (B) a progressive shift of climate zones toward the poles, which extend the tropics, as indicated by intensified cyclones and floods, and enlarging desert regions as manifested by extreme droughts and fires. Given lag effects, looming threats include (1) ocean acidification, collapse of coral reefs and the marine food chain; (2) mountain snow and glacier melt and availability of freshwater; (3) destruction of native habitats, i.e. the Amazon; (4) ozone depletion; (5) atmospheric aerosol loading and (6) chemical pollution by metals, plastics, radioactive nuclei.
The consequences for human habitats include loss of arable land, fresh water supplies and extreme weather events. The loss of Himalayan snow and thereby decreased river flow, coupled with a failure of the monsoon and sea level rise, threatens more than one billion people in south and south-eastern Asia. As the polar regions warm, a release of methane from the many hundreds of billions of tons of carbon stored in permafrost and shallow lakes and seas, is imminent.
In the view of leading climate scientists there is no alternative to attempts at reducing atmospheric CO2 levels to below 350 ppm as soon as possible. What is urgently required is a combination of (A) urgent deep cuts in carbon emissions; (B) fast-track development of clean renewable energy systems; (C) an intensive global reforestation campaign; (D) application of a range of CO2 draw-down sequestration measures, including world-wide replantation and reforestation campaigns and chemical capture methods, solar-powered desalination plants, and long-range channel and pipe water transport systems.
Recent references
Schellnhuber, Oxford meeting, 28-30.10.09 http://www.eci.ox.ac.uk/4degrees/programme.php
British Antarctic Survey http://www.antarctica.ac.uk/press/press_releases/press_release.php?id=989 NASA/GISS). http://data.giss.nasa.gov/gistemp/
Copenhagen Synthesis Report http://www.anu.edu.au/climatechange/content/news/copenhagen-synthesis-report-released-today/
Hansen et al. 2008. Target CO2: Where Should humanity aim? http://www.columbia.edu/~jeh1/2008/TargetCO2_20080407.pdf
Lenton et al., 2008. Tipping points in the Earth climate system. http://www.sciencedaily.com/releases/2008/02/080204172224.htm
Reports by NASA/GISS, Hadley_Met, Potsdam Ocean Institute, NSIDC, CSIRO, BOM.
Andrew Glikson
Earth and paleoclimate scientist
22 October, 2009
Of course we are all going to die. Death is 100% certain. But people will die in such ways as cancer, heart attacks, accident or old age . Not of climate change.
Please Clive, no more.
Correction:
The Oxford conference took place on the 28-30 September, 09.
At last some one is getting really close to telling it how it is going to be!! Working with and understanding nature (ecology) brings with it the understanding that it is human arrogance to believe that we really understand nature at all – we can’t. What we have learned is that at some point (recognisable only in hindsight) we have gone too far and nature has reacted in a quite unpredictable way. It is recognised only after the event – on one can predict it in advance. What will be the first catastrophe of cataclysmic magnitude from climate change may well be in the pipeline. It wouldn’t matter that much – humans have got through extreme events (even world wars) BUT this time what is at stake is life on earth as we know it. Cost of action is not the issue. Cost of inaction is. Climate change is occurring now – it WILL affect our children let alone our grandchildren. The window of opportunity to take effective action is rapdly closing – have our political systems the ability to act decisively? The present debate about emissions trading in Australia says (see Crikey 21/10/09) we haven’t a chance in hell. If we can’t afford to stop mining coal then the earth can no longer afford to keep us on it in the way in which we have become accustomed. Thanks Clive for making it so starkly clear.
Without needing to know the specifics of the science, I was convinced decades ago that the damage humans were doing to the earth would ultimately lead to our own untimely demise as a species. Long before it was trendy to be an environmentalist I was pleading with people to consume less, reduce waste, conserve energy etc etc and was laughed at. As soon as Al Gore and his doco made it fashionable to be green people were telling me off for leaving a lightbulb on for five seconds longer than needed – but I digress into gripehood.
The point is, I saw Crikey’s “oh shit moment” blog, pondered it, and I realised I really didn’t have an “oh shit” moment, more a longer realisation that our global capitalist economy would never put people or planet ahead of profit. So increasing evidence that its all too little too late comes as no surprise to me. I never expected anything different. Pessimistic, I know – but realistic I am sure. So while I support doing what we can to mitigate the effects of climate change, I think our main priority should be reducing the global population – one of the main causes of the problem and those (this and the next generation/s) who will suffer the most.