I attended the launch event for the “Climate Change: A Risk Assessment” report on the 13th July. This independent report was commissioned by the UK’s Foreign and Commonwealth Office (FCO) and involved collaborative research from scientists in the UK, the US, and China applying risk assessment principles used in finance and national security to better understand the risks of climate change.
Sir David King was introduced as the member for the FCO with probably the highest carbon footprint, since he has visited over 60 countries, many of them more than twice! He explained that in the realms of finance and national security, governments and other players are used to assessing, planning for, and ideally preventing worse case scenarios. For example, the government wanted to assess the worst case scenario with the H5N1 virus, and how they would cope if it became communicable between humans. In the case of climate change, however, most reports have not considered what would happen if the global average temperature rose by more than 4-5°C. Very little study has been done on the impacts of these higher levels of temperature change.
Part of the problem here is that there are three key variables to assess: probability, impact, and time. Usually time is the fixed variable, so that charts show the probability of a range of impacts. In this report the authors have made impact the fixed variable, using impact scenarios that are clearly intolerable worst cases. The charts then show the probability of reaching this level of impact over time. King used the hypothetical example of the boiling frog who might ask what the situation will be in 2 minutes and be told that most likely he would be very happy in some warmer water. The question he really should be asking is what action he needs to take now to avoid boiling to death in 10 minutes!
A sobering example taken from the report is illustrated in the chart below which shows the probability that people will not be able to survive heatwaves in different regions of the world. This means that at temperatures 6°C above pre-industrial levels, c.80% of people in Northern India would be expected to die unless they have air conditioning. Given the several thousand deaths from heat exhaustion earlier this year in India and Pakistan, this sort of scenario must surely be taken seriously.
And yet, on current projections of greenhouse gas emissions, this is where we would expect the world’s temperature to reach by c.2200. The point is that from this analysis, a 6°C temperature rise is something that we should wish to avoid at all costs, and avoiding this risk requires action now. Other risks assessed in the report include crop survivability, water stress, drought, and sea level rises.
Sir Martin Rees, the Astronomer Royal and eminent physicist comments in the report that many of the builders and designers of Europe’s great cathedrals knew that they would not live to see them finished. They were motivated to leave a legacy for future generations – a truly long-term perspective, and one that we are still benefitting from. When it comes to action on climate change a similarly long-term perspective is required. It is to be hoped that this report will help to motivate the political leaders of the world to take such a long-term perspective when they meet in Paris later this year.