Air quality and health implications of 1.5 °C–2 °C climate pathways under considerations of ageing population: a multi-model scenario analysis

Peter Rafaj,Jérôme Hilaire,Peter Kolp,Christoph Bertram,Shinichiro Fujimori,Lara Aleluia Reis,Detlef Van Vuuren,Volker Krey,Zbigniew Klimont,Gregor Kiesewetter,Mathijs Harmsen,Wolfgang Schoepp,Daniel Huppmann,Laurent Drouet,Oliver Fricko

doi:10.1088/1748-9326/abdf0b

Abstract

Low-carbon pathways consistent with the 2 °C and 1.5 °C long-term climate goals defined in the Paris Agreement are likely to induce substantial co-benefits for air pollution and associated health impacts. In this analysis, using five global integrated assessment models, we quantify the emission reductions in key air pollutants resulting from the decarbonization of energy systems and the resulting changes in premature mortality attributed to the exposure to ambient concentrations of fine particulate matter. The emission reductions differ by sectors. Sulfur emissions are mainly reduced from power plants and industry, cuts in nitrogen oxides are dominated by the transport sector, and the largest abatement of primary fine particles is achieved in the residential sector. The analysis also shows that health benefits are the largest when policies addressing climate change mitigation and stringent air pollution controls are coordinated. We decompose the key factors that determine the extent of health co-benefits, focusing on Asia: changes in emissions, urbanization rates, population growth and ageing. Demographic processes, particularly due to ageing population, counteract in many regions the mortality reductions realized through lower emissions.

Highlights

The central goal of the Paris Agreement – adopted in 2015 by the United Nations FrameworkConvention on Climate Change - is to intensify global efforts to mitigate risks of climate change by keeping a global temperature rise within century well below 2 degrees Celsius relative to pre-industrial levels, and to push further towards strategies to limit the rise in AcAUTHOR SUBMITTED MANUSCRIPT - ERL-110311.R1cri pt temperature below 1.5 degrees Celsius [1]
Our multi-model assessment suggests that low carbon pathways alone will not be sufficient to provide the majority of highly impacted population - in particular in Asia - with air quality complying with the World Health Organization (WHO) standards
2oC climate targets show strong declining trend relative to current emission levels as well as in comparison to the moderate reductions achieved by the Nationally Determined Contributions (NDC) mitigation policies

Summary

Introduction

The central goal of the Paris Agreement – adopted in 2015 by the United Nations FrameworkConvention on Climate Change - is to intensify global efforts to mitigate risks of climate change by keeping a global temperature rise within century well below 2 degrees Celsius relative to pre-industrial levels, and to push further towards strategies to limit the rise in AcAUTHOR SUBMITTED MANUSCRIPT - ERL-110311.R1cri pt temperature below 1.5 degrees Celsius [1]. Literature shows that reaching the Paris targets will require a major transformation of the energy and land-use systems. It implies several or all of the following: a) reaching net zero carbon dioxide (CO2 ) emissions globally around the middle of the century and simultaneous deep cuts in emissions of nonCO 2 greenhouse gases (GHGs); b) restructuring the energy system through demand reductions, decarbonization of power and fuel supply, electrification of energy end -use, c) major reductions in agricultural GHG emissions, d) possibly removal of CO 2 from the atmosphere, e) and societal changes towards low demand patterns for land- and GHGintensive goods. The health risk posed by air pollution impacts both urban and rural communities, with the total mortality burden from indoor and ambient air pollution being fifth behind dietary, high blood pressure, tobacco and diabetes risks [14]

Results

Discussion

Conclusion