The IPCC 5th Assessment Report – Working Group 3 Mitigation Report is finally out there, for all of you to read…. Of course, 2,000 pages are probably too many, so it may be more feasible to read only the Summary for Policy Makers… But if you are a scientist interested on climate change mitigation, then my advice is that you should download the chapters of your interest and read them. You will be able to find a thorough review of the ‘state of the art’ and many useful references…
We have worked over two years to provide the world with the most updated science about climate change mitigation and to highlight where we are in terms of global greenhouse gas emissions, where we seem to be going and what has been done so far by policy-makers around the world. Unfortunately, the IPCC is policy relevant but not policy prescriptive, i.e. you will not find the recipe of ‘what should be’ done if we were to become genuinely committed to live within a ‘safe’ climate in the near future.
The overall message of our review is not, in my view, an optimistic one. In spite of a growing number of (but not enough, or sufficiently ambitious) policies and regulations to incentivise climate change mitigation, global emissions have continued to rise in the last decade. More worrying is the fact that the decarbonisation trend observed between 1970s and early 2000s (i.e. we increasingly emitted less CO2 per unit of GDP) has been reversed. The long-term global scenarios analysed in the report suggest that without more mitigation efforts, the global mean temperature by the end of the century is likely to increase between 3.7 and 4.8 oC above pre-industrial levels. This is far beyond the 2 oC limit considered to be the threshold to maintain ourselves within a relatively stable and ‘safe’ global climate (see Working Group 2 Report on Impacts and Adaptation).
Embracing mitigation seriously would require ambitious efforts, and these should start without further delay. If we are to keep within the ‘safe’ 2 oC threshold, we would need to upscale zero or low-carbon technologies and reduce our current emission levels between 40% and 70% by 2050. This is an incredible challenge that might have an economic cost, but might also generate direct and indirect benefits for certain economic sectors and for society as a whole.
We know that climate change will have divergent consequences around the globe and human adaptation will thus need to be locally and nationally understood and informed. Seemingly, mitigation efforts can be informed and developed according to country development strategies and the nature of different economic and social sectors. Nonetheless, and in lieu of our Report findings, I personally believe that the United Nations Framework Convention on Climate Change should soon set up the foundations for large-scale emission reductions across the world. And this is only possible if the world’s largest emitters agree on a carbon pricing mechanism that stimulates innovation in the energy supply and industry sectors across and, subsequently, send the right signals that access to the atmospheric sink is not a ‘free-for-all’. Additionally, investments in carbon-intensive technologies should be minimized or at least should not be supported by multinational, public institutions, to avoid carbon lock-in in the medium term.
Continuous policy procrastination is of course possible, but it is likely to worsen the climate change phenomena and put millions of people around the planet increasingly at risk of drought, severe rainfall, and ice melting, among others. International and national policy-makers should consider all possible options to meaningfully address the mitigation challenge, globally and nationally, and stimulate an honest debate across governance scales about costs and benefits, widely understood. Economic costs should be discussed alongside environmental and health benefits, including their distribution, and the short-term versus long-term implications of ambitious mitigation goals should also be put on the table of national and international negotiations. Compensatory measures for countries, sectors or people who may be negatively affected by ambitious mitigation policy can be enacted.
The IPCC has made the latest science available and it is now time for policy-makers to take stage and lead the transition I think we require. We will soon know if they have endorsed the challenge or if they have preferred to standstill, and watch the weather change while crossing their fingers for not to be caught in ‘the storm’….