There is overwhelming evidence that the average temperature of the earth is rising and we have understood the contribution of greenhouse gases to that process for 150 years. Given the potentially, and increasingly likely, disastrous consequences the precautionary principle requires that we take action now to reduce the burning of fossil fuels.
The Summary for Policymaker, Working Group I contribution to the IPCC Fifth Assessment Report is now available.
In each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850.
“Human influence has been detected in warming of the atmosphere and the ocean, in changes in the global water cycle, in reductions in snow and ice, in global mean sea level rise, and in changes in some climate extremes. This evidence for human influence has grown since AR4. It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.”
“It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together. The best estimate of the human induced contribution to warming is similar to the observed warming over this period.”
Lord Stern in a paper in the Journal of Economic Literature has argued that current climate change models underestimate of the costs of the consequences. Stern argues that a new generation of models is needed with a stronger focus on lives and livelihoods, including the risks of large-scale migration and conflicts. The risks include vast movements of population fleeing land made uninhabitable by climate change. Arguably we are already seeing the consequences of climate change generating the civil war in Syria.
Stern describes the likely impact on the world after a rise of 3-4°C “Much of southern Europe may look like the Sahara desert, much of the snow and ice on the Himalayas gone. The North India monsoon, which shapes the agricultural lives of hundreds of millions may be radically altered. Rainforests might die.” “Unlike past wars, which could be settled by peace treaties, the reasons for the movements causing such conflicts, a changing climate could not simply be ‘switched off'”.
Of the climate change deniers Stern said “It would be extraordinary to argue on the basis of 200 years of evidence that you’re confident that the risks are small. Those who would have us delay have to argue that they’re confident the risks are small . It would be an astonishing statement to make in the light of all this evidence.”
The Stern Review Report published in 2006 on the economics of climate change argued compellingly that the sooner the challenge of decarbonising our economies was tackled the less it would disrupt our economies. The UK has now joined with Norway, Sweden and four other countries to commission “Stern 2.0” to be published in September 2014, Stern will be the Reviewer for the new report.
In a report in The Times on 25th September Lord Stern said that China is likely to announce that coal consumption will peak five years earlier, in 2025 rather than 2030, The announcement is likely to come before the 2015 summit in Paris when governments will try to reach a global deal on emissions.
The new report is undertaken by Global Commission on the Economy and Climate set up by the UK, Norway, Sweden, Indonesia, South Korea, Colombia and Ethiopia. Funding of $8.9m has been provided, mostly by Norway, Sweden and the UK. The members include business leaders such as Paul Polman, Unilever chief executive, and several former prime ministers and presidents, including Felipe Calderón, the commission chairman and former president of Mexico.