On Friday the Inter-Governmental Panel on Climate Change (the IPCC) published the first part of their fifth Assessment Report on climate change. The Assessment Reports are a summary of the best available scientific knowledge, and are each divided into three parts: on the physical science basis; on impacts of climate change, 
vulnerabilities, and means of adaptation to the impacts; and on mitigation (which essentially means actions to reduce the volumes of greenhouse gases emitted as a result of human activity). The first Assessment Report was completed in 1990 and the Fourth in 2007. The Assessment Reports synthesize the work of thousands of scientists across the world. The result is a scientific assessment that is as solid and reliable as anything that exists anywhere.
The report published on Friday only adds weight to many things that were already clear: that warming of the of the climate system is indisputable, that most of the recent warming has been caused by human activity and that without significant reductions in emissions, global temperatures are likely to be at least 2°C above pre-industrial levels – probably a low estimate given that they have already risen on average by 0.8˚C over the last century – and could be as much as 5°C higher than by the end of this century.
The Report also notes that the risks of future climate change are even higher than previously thought. My own view is that all the IPCC’s reports have been relatively conservative in their conclusions, and that the consensus view of the certainty, the impacts, and the economic consequences of climate change has become steadily more gloomy over the last few years. It’s therefore likely that the latest report errs, if anything, on the side of caution in its conclusions.
The Report is another reminder that we are facing an enormous challenge. Climate change will affect – is affecting – all of us, and all of us need to be part of the solution. Governments need to act more urgently, both domestically and in working towards a legally-binding global agreement – which is due to be finalised by late 2015, and come into effect in 2020. This is a key priority in Britain’s foreign policy, and one we’ll continue to pursue in our work with the Government of Uzbekistan.
If you want to read the full “Summary for Policymakers” of the Report, it’s here.