For all sorts of reasons this blog post has been a long time in preparation. On Wednesday 21 May I attended a lecture at the Institute of Physics in London by Professor Jim Skea on Mitigation of Climate Change. The lecture related to the report of Working Group 3 (WG3) of the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC). Prof Skea was one of the co-chairs of WG3 and I found it particularly challenging to hear directly from someone involved in producing the report rather than just read it on the computer screen.
Professor Skea began by reminding us of some of the key conclusions in the Summaries for Policy Makers (SPM) for WG1 and WG2.
• From WG1 there is a clear relationship between cumulative emissions of greenhouse gases and temperature increase. We have already used up about half of the allowed budget for having a reasonable probability of constraining the temperature rise to 2oC above the pre-industrial level.
• From WG2 it is apparent that we are already seeing a variety of impacts that can be attributed with varying levels of confidence to anthropogenic influence. The projected risk of further impacts increases with temperature rise (the “Burning Embers” diagram).
Within the short space of a blog post it is not possible to cover adequately all that Prof Skea said. I would therefore encourage you to read and pray about the SPM and the SPM for WG1 and WG2. They are all written to be read by non-specialists and are available on the IPCC website. Some of the key points that I picked up were:
• The growth of greenhouse gas emissions has accelerated – most of this change comes from fossil fuels;
• Due to increased coal use the carbon intensity of energy has increased in the last decade after a period of reduction;
• Most of the growth has come from upper and middle income countries. This had been contentious and the related figure was not included in the SPM but remains in the Technical Summary;
• Policy delays would increase the difficulty and narrow the options for constraining the temperature rise to less than 2oC above pre-industrial:
• Scenarios with a delayed emissions peak typically required negative emissions late in the century. These would require either biomass combustion with carbon capture and storage (CCS) or significant amounts of land use change (eg reforestation). It was pointed out that CCS has not yet been demonstrated at a large scale;
• The pledges made so far by individual nations are insufficient to sufficiently limit the risk of exceeding a temperature increase of 2oC above pre-industrial.
The production of the report of WG3 completes the three parts of the Fifth Assessment Report of the IPCC. The Synthesis Report drawing it all together is due later in 2014 although there have recently been suggestions in the press as to what it might contain. The scientists have therefore presented their assessment and it is now for policy makers to respond. How they respond will have implications for all of us and our descendants and also even more significantly for those in the poorer parts of the world. For those of us who are Christians the command to love our neighbour as ourselves requires that we respond both by examining our own lifestyles to reduce our carbon footprint but also in our churches by exercising a prophetic role in challenging and holding to account our policy makers for the response they make nationally. Please also pray for real progress to be made in the next round of COP talks in Lima later this year and the run up to the COP Meeting in Paris at the end of 2015.
Peter R G Lornie
JRI Blog Editor