Human link to climate change stronger than ever
December 2012
Human link to climate change stronger than ever: draft report
http://www.reuters.com/article/us-climate-ipcc-idUSBRE8BD0VV20121214
According to a leaked draft report by an influential panel of experts, international climate scientists are more certain than ever that human activity is responsible for global warming, rising sea levels and extreme weather events.
It is worth striking a note of caution before going any further. The draft was shown on a climate change skeptic blog. The report is still a work in progress and this early draft is subject to change before a final version is released in late 2013. This unauthorized, premature posting of the draft seems designed to produce confusion, with climate change deniers pointing to disparities in the details to cast doubt upon the underlying science. The IPCC emphasise that the report is likely to change before it is released.
However much the details may or may not change, the overall message is clear and emphatic. The early draft shows that a rise in global average temperatures since pre-industrial times is set to exceed 2 degrees Celsius by 2100, and may reach 4.8 Celsius. And the Intergovernmental Panel on Climate Change (IPCC) draft report is clear as to the cause of this increase in temperatures: "It is extremely likely that human activities have caused more than half of the observed increase in global average surface temperatures since the 1950s."
"Extremely likely" is a highly significant term. In the language of the IPCC, it means a level of certainty of at least 95 percent. The next level is "virtually certain", or 99 percent, the greatest possible certainty for the scientists. In its previous report of 2007, the IPCC said it was at least 90 percent certain that human activities, led by burning fossil fuels, were the cause of rising temperatures. For climate change deniers this is not sufficient evidence. In emphasising uncertainty – and all science works in uncertainty – they demand what science cannot deliver – certainty. And people who know little of science fall for the tactic. Deniers continue to demand ‘conclusive evidence’ or ‘proof’ before action can be taken. Leaving aside the fact that proof is something that is proper to the field of mathematics, five years on and we are now just one level below ‘virtually certain’. There is only one thing wrong with waiting until we reach this level. By the time we are ‘virtually certain’ that human activity is responsible for rising global temperatures, it will be too late to act.
There is little doubt about the seriousness of the environmental threat we face. The IPCC draft expresses "high confidence" that human activity has caused large-scale changes in oceans, in ice sheets or mountain glaciers, and in sea levels in the second half of the twentieth century. The draft also claims that human influence lies behind some extreme weather events.
The draft's various scenarios forecast a rise in temperatures of between 0.2 and 4.8 Celsius in the twenty first century. However, almost all of the scenarios predicted a rise in excess of 2 degrees Celsius. The figure is significant. A 2 degrees global temperature rise is a threshold seen by scientists as the maximum if extreme weather, droughts, floods, and other climate change impacts are to be avoided. Although governments pledged to curb emissions to remain the safe side of the 2 degrees threshold, the draft report argues that carbon dioxide concentrations in the atmosphere are the highest in 800,000 years.
The draft also claims that sea levels are likely to rise by between 29 and 82 centimetres by the end of the century, an increase on the 18-59 centimetres projected in the 2007 report.
Rising sea levels threaten storm surges, coastal erosion and, in the worst case scenario, the complete swamping of large areas of land. The report stopped short of including some research carried out since 2007 that suggested a sea level rise of up to 2 meters by 2100. However, there is no doubt that people living in low-lying areas all over the world at risk, from Bangladesh to the cities of New York, London and Buenos Aires.
The draft also included a possible future acceleration of ice loss from Antarctica and Greenland.
There is little more that scientists can do. At a certain point, we move from the world of fact to the world of value, from science to ethics and politics. The scientists have played their part, now it is up to the citizens of the world and the people that represent them.
There is little sign of the effective, concerted action required to deal with global heating. Not only was there no progress last week at the United Nations conference meeting to curb emissions of the greenhouse gases blamed for global heating, three countries - Canada, Russia and Japan - have abandoned the Kyoto Protocol limiting the emissions. The United States never ratified the treaty in the first place, and it excludes developing countries where emissions are growing most quickly. Instead of further action, what precious little common agreement has been achieved is unravelling. Whilst countries agreed to extend Kyoto to 2020, only those covering less than 15 percent of world greenhouse gas emissions signed up. In light of this, developing nations are arguing for a U.N. mechanism to compensate them for the impact of climate change. And that, I’m afraid, is the best that the world of government and politics has been able to achieve in face of the biggest threat that human civilisation has ever faced. Many people express disdain at the world of conventional politics and demand democracy. It’s about time the individuals composing the demos realised that if they want democracy, they are going to have to join together, forge public bonds at the heart of civil society, and constitute democracy themselves as active, informed citizens.