Source: IPCC 2014

The second instalment of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report was launched yesterday. Entitled ‘Climate Change 2014: Impacts, Adaptation and Vulnerability’, it gives an overview of the impacts, vulnerabilities and exposure to climate change observed to date as well as examining futures risks (and benefits) and opportunities for effective adaptation.

The report finds that ‘changes in climate have caused impacts on natural and human systems on all continents and across the ocean’. The evidence of climate-change impacts is strongest for natural systems. Looking to the future: ‘climate change is projected to amplify existing climate-related risks and create new risks for natural and human systems. Some of these risks will be limited to a particular sector or region, and others will have cascading effects. To a lesser extent, climate change is also projected to have some potential benefits.’

The report outlines how risks from climate change depend on differences in vulnerability and exposure that arise from various inequalities within uneven development processes. How the risks from climate change evolve over time will therefore depend not only on the degree of climate-change but on these development processes.

The steps that can be taken to limit the impacts of climate change are also a central focus of the report (this also happens to be the subject of the Royal Society policy project on Human Resilience to Climate Change and Disasters). Lessons can be learnt from what has already been done; societies have had to deal with climate variability and extremes throughout history, with different levels of success. The impacts from climate-related extremes indicate that societies are often not well adapted to current climate variability. More recently, adaptation is becoming embedded in planning processes (though the report notes that implementation of adaptation responses is more limited).

When looking at what is currently being done, engineered and technological options are noted as commonly implemented adaptive responses. However, there is increasing awareness of the need for a broader variety of adaptation options. The value and benefits of social, institutional and ecosystem-based measures are being recognised.

Mitigation is also highlighted as the ultimate adaptation option: ‘The overall risks of climate change impacts can be reduced by limiting the rate and magnitude of climate change. Risks are reduced substantially under the assessed scenario with the lowest temperature projections (RCP2.6 – low emissions) compared to the highest temperature projections (RCP8.5 – high emissions), particularly in the second half of the 21st century (very high confidence).’ Mitigation of climate change will be the focus of the third report from the IPCC in a few weeks time.

Comments from members of the Royal Society Working Group on ‘Human Resilience to Climate Change and Disasters’ and the Working Group Chair, Professor Georgina Mace FRS, can be read here.