Page - 10 - in options, Volume summer 2021

W ind turbines do not belch sulphurous fumes; solar panels emit no choking dust; electric vehicles have no exhaust pipes. It seems obvious that by rolling out these technologies, all aimed at fighting climate change, we will also cut air pollution. But it is far from obvious how powerful an effect that will be. What will climate policies mean for global health? How far can they take us on the road to clean air? Researchers from the climate and air quality communities have been working together to answer these questions. The Paris Agreement added new momentum, making sustainable development an explicit focus of the climate effort, as air pollution is a particular threat to development in poorer regions. A recent IIASA study looked at the public health implications of the Paris Agreement across nine countries – including China, India, and the US – which are home to half of the world’s population. The research also covers the health impacts of diet and physical activity, but IIASA researchers Gregor Kiesewetter and Peter Rafaj focused on air pollution – specifically PM2.5, the fine particulate matter that is damaging to health and responsible for more than 7% of all deaths worldwide – using the IIASA Greenhouse gas Air pollution INteractions and Synergies model (GAINS). GAINS models emissions of pollutants, their chemical interactions, and their path through the atmosphere, and finally calculates the impact on human health and ecosystems. One scenario portrays a world that meets the Paris goal of staying under 2°C of global warming, and also other Sustainable Development Goals (SDGs), such as access to clean energy. The result of this was 1.2 million fewer annual deaths due to air pollution in the nine countries, compared with a scenario based on existing clean-air policies and climate commitments. This message was reinforced in a second study led by Rafaj, looking ahead to 2050 and examining health impacts across Asia. Scenarios that meet the 2°C and 1.5°C targets show great health benefits, averting up to 13 % (or 0.5 million) of annual premature deaths seen in the baseline scenario of today’s climate and energy policies. In addition, climate action brings cost savings: cutting one tonne of CO2 means €5 to €12 less spent on abating pollution. The prospect of these lives and dollars saved should be a spur to policymakers considering more ambitious climate goals at the upcoming UN climate conference, COP26, in Glasgow. Climate action alone is however not enough. Pollution is a huge and growing problem, largely because an ageing population is increasingly vulnerable to the cardiovascular diseases linked to PM2.5. Rafaj and colleagues examined this demographic effect, and found that even if emissions are held steady, premature mortality in Asia rises fast, which suggests that even stricter policies are needed. Clean air needs more than climate policy Actions to curb global warming can have an added benefit—cutting air pollution and saving millions of lives. This bonus however only takes us part of the way to truly clean air. We need ambitious policies focused on pollution – and urgently. www.iiasa.ac.at10