Friday, June 19, 2009

Researchers Update Climate Science: "The Clock Is Ticking”

Jun 18: Following the June 16, release by the Obama Administration of an update report on climate change in the United States [See WIMS 6/16/09] , a new international update report has also been released. A report synthesizing the newest research results relating to climate change and what action can be taken in response to climate change was presented at the European Policy Centre (EPC) in Brussels. The report is being released six months (170 days) before the UN Climate Change Conference (COP15) begins in Copenhagen. The host of the COP15, the Prime Minister of Denmark, Lars L√łkke Rasmussen, received the report.

The 36-page report is written for the non-specialists and is based on discussions and presentations made at the scientific congress “Climate change: Global Risks, Challenges & Decisions” held in Copenhagen in March. The synthesis report was written by a team of researchers from around the world and it has been vetted by a long list of researchers and organizations. The effort was coordinated by the International Alliance of Research Universities (IARU).

Professor Katherine Richardson, Chair of the Scientific Steering Committee of the congress and Chair of the writing team said, "The newest evidence indicates that society faces serious risks even with a global temperature rise of only about 2 degrees. If society wants to minimize these risks, then action must be taken now. Society has all the tools necessary to respond to climate change. The major ingredient missing is political will. Already many societies are struggling with the effects of climate change. If society wants to avoid even more serious, and in most cases irreversible impacts of climate change, then there is very little time left. The greenhouse gases in the atmosphere are already at a level that is predicted to cause warming of around 2 degrees so major emission cuts should be made immediately to retain climate change. The clock is ticking.”

Professor John Schellnhuber, Director of the Potsdam Institute for Climate Impact Research and member of the writing team said, "Even if we keep global warming below two degrees, we will still see extreme effects of climate change on our societies, and data collected since the production of the 2007 IPCC Report indicate that several climate indicators (for example, sea-level rise, ocean temperature, glacier-melt, Arctic sea ice melt, ocean acidification) all are changing at the maximum rate projected at the time of the last IPCC report or even faster."

The report indicates that, "The scientific evidence has now become overwhelming that human activities, especially the combustion of fossil fuels, are influencing the climate in ways that threaten the well-being and continued development of human society. If humanity is to learn from history and to limit these threats, the time has come for stronger control of the human activities that are changing the fundamental conditions for life on Earth."

One of the six key messages of the report is that, "Rapid, sustained, and effective mitigation based on coordinated global and regional action is required to avoid 'dangerous climate change' regardless of how it is defined. Weaker targets for 2020 increase the risk of serious impacts, including the crossing of tipping points, and make the task of meeting 2050 targets more difficult and costly. Setting a credible long-term price for carbon and the adoption of policies that promote energy efficiency and low-carbon technologies are central to effective mitigation."

The report predicts a sea-level rise of about a meter or more by 2100. However, it is indicated, "Sea-level rise will not stop in 2100. Changes in ocean heat content will continue to affect sea-level rise for several centuries at least. Melting and dynamic ice loss in Antarctica and Greenland will also continue for centuries into the future. Thus, the changes current generations initiate in the climate will directly influence our descendents long into the future. In fact, global average surface temperature will hardly drop in the first thousand years after greenhouse gas emissions are cut to zero."

The report indicates that the IPCC analysis concluded that atmospheric CO2 concentration should not exceed 400 ppm CO2 if the global temperature rise is to be kept within 2.0 – 2.4°C. In a sobering explanation of the challenge ahead, the report indicates, ". . .atmospheric CO2 concentrations are already at levels predicted to lead to global warming of between 2.0 and 2.4°C. If society wants to stabilize greenhouse gas concentrations at this level, then global emissions should, theoretically, be reduced by 60-80% immediately, the actual amount being dependent upon the amount that will be taken up by oceans and land. Given that such a drastic immediate reduction is impossible, greenhouse gas concentrations will continue to rise over the next few decades. An overshoot of the atmospheric greenhouse gas concentrations needed to constrain global warming to 2°C is thus inevitable. To limit the extent of the overshoot, emissions should peak in the near future. Recent studies suggest that if peak greenhouse gas emissions are not reached until after 2020, the emission reduction rates required thereafter to retain a reasonable chance of remaining within the 2°C guardrail will have to exceed 5% per annum. This is a daunting challenge when compared to a long-term average annual increase of 2% in emissions. The conclusion from both the IPCC and later analyses is simple -- immediate and dramatic emission reductions of all greenhouse gases are needed if the 2°C guardrail is to be respected. . ."

The synthesis report has been put together by a writing team of 12 internationally respected scientists from all continents and has gone through an extensive scientific review by the Scientific Steering Committee, scientists from the International Alliance of Research Universities, the session chairs at the congress, and the Earth System Science Partnership (ESSP).

Access a release on the report from IARU (
click here). Access the complete report (click here). Access the IARU website for additional information (click here).