Emissions of air pollutants have negative impacts on human health, food security and climate© EU, 2011 - Photo: B.Scheeren
Study co-authored by the JRC on climate change mitigation published in Science
A scientific paper published today by Science shows that a limited number of air quality measures can substantially mitigate global warming and have significant benefits for human health and agriculture. Together with twelve partners from all over the world, including UNEP, NASA and the Stockholm Environment Institute, JRC scientists identified 14 emission control measures that can best help to limit global warming and improve health and food security in the coming decades.
The paper, entitled ‘Simultaneously mitigating near-term climate change and improving human health and food security’, builds on the United Nations Environment Programme (UNEP)’s (2011) Integrated Assessment of Black Carbon and Tropospheric Ozone*. The Science paper extends this Assessment by providing more detailed climate modelling (in particular identifying detailed precipitation impacts), extending the impact analyses to the national level with more detailed spatial information, and providing more detailed cost-benefit analyses. It finds that only a small fraction of air quality measures provide substantial warming mitigation, but that if these are immediately applied, in conjunction with measures to reduce carbon dioxide, they can help keep global warming below 2ºC relative to preindustrial levels, mitigate warming in the Arctic and Himalayas, and reduce regional disruption to traditional rainfall patterns. It concluded that such strategies would help prevent up to 5 million annual premature deaths from air pollution, and increase annual crop yields by 30-135 million tonnes. The benefits of methane reductions were estimated at US$700-5,000 per tonne.
*The Integrated Assessment of Black Carbon and Tropospheric Ozone was initiated by UNEP and the World Meteorological Organization to investigate emission reduction measures which can lead to an improvement in air quality while also benefiting the climate. 2,000 measures to reduce black carbon and methane, a major precursor of ozone and a greenhouse gas, were screened and 14 of these measures were found to account for nearly 90% of global warming reduction potential. The Assessment developed future emission scenarios in which these 14 measures are applied from 2010 through to 2030. These climate simulations showed that the implementation of methane and black carbon emission reduction measures, alongside substantial CO2 emission reduction measures, would most probably limit global warming to under 2°C over the next 60 years as compared to pre-industrial times.
The integrated models to evaluate the impact of human activities on climate change and air quality, developed by JRC, were at the basis of the study. JRC scientists also contributed to the preparation of the emission inventories used in the study and applied the three-dimensional composition-climate ECHAM5-HAMMOZ General Circulation Model to assess how changes in emissions due to human activities can influence present and future climate. They also estimated the impacts of the proposed emission reductions on crop yields around the world and contributed to their evaluation on human health.
Changes in temperature compared to the 1890-1910 period:
Observed temperatures until 2009 and projected temperatures thereafter under various emission reduction scenarios, relative to pre-industrial times.