IIASA researchers have contributed to a major new report in The Lancet medical journal looking at the effects of climate change on human health, and the implications for society.

The 2018 Report of the research coalition The Lancet Countdown: Tracking Progress on Health and Climate Change shows that rising temperatures as a result of climate change are already exposing us to an unacceptably high health risk and warns, for the first time, that older people in Europe and the East Mediterranean are particularly vulnerable to extremes of heat, markedly higher than in Africa and SE Asia. The risk in Europe and the Eastern Mediterranean stems from aging populations living in cities, with 42% and 43% of over-65s respectively vulnerable to heat. In Africa, 38% are thought to be vulnerable, while in Asia it is 34%.

The report also states that ambient air pollution resulted in several million premature deaths from ambient fine particulate matter globally in 2015, a conclusion from IIASA researchers confirming earlier assessments. Since air pollution and greenhouse gases often share common sources, mitigating climate change constitutes a major opportunity for direct human health benefits.

Leading doctors, academics and policy professionals from 27 organizations have contributed analysis and jointly authored the report. Alongside IIASA, the partners behind the research include the World Bank, World Health Organization (WHO), University College London and Tsinghua University, among others.

IIASA researcher Gregor Kiesewetter led a team from the Air Pollution and Greenhouse Gases research program that estimated the dangers of air pollution to human health. A new and important finding this year was the global attribution of deaths to source. Kiesewetter and the team found that coal alone accounts for 16% of pollution-related premature deaths, around 460,000, which they state makes phasing out coal-use a "crucial no-regret intervention for public health."

Kiesewetter and the team used the GAINS Model, developed at IIASA, which calculates the emissions of precursors of particulate matter based on a detailed breakdown of economic sectors and fuels used.

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Large contributions to ambient air pollution come from the residential sector, mostly from solid fuels like biomass and coal. Industry, electricity generation, transport, and agriculture are also important contributors. While coal should be a key target for early phase-out in households and electricity generation as it is highly polluting, it is not all that should be done.

"The attribution shows that unfortunately an approach targeting a single sector or fuel won't solve the problem -- air pollution is a multi-faceted issue that needs integrated strategies cutting across many sectors, which will differ from country to country. This is what we typically do with the regional and local GAINS model: giving advice to policymakers on the most efficient approaches to tackle air pollution in their specific settings," says Kiesewetter.

The report contains a number of other headline findings: -

157m more vulnerable people were subjected to a heatwave in 2017 than in 2000, and 18m more than in 2016.

153bn hours of work were lost in 2017 due to extreme heat as a result of climate change. China alone lost 21bn hours, the equivalent of a year's work for 1.4% of their working population. India lost 75bn hours, equivalent to 7% of their total working population.

Heat greatly exacerbates urban air pollution, with 97% of cities in low- and middle- income countries not meeting WHO air quality guidelines.

Heat stress, an early and severe effect of climate change, is commonplace and we, and the health systems we rely on, are ill equipped to cope.

Rising temperatures and unseasonable warmth is responsible for cholera and dengue fever spreading, with vectorial capacity for their transmission increasing across many endemic areas.

The mean global temperature change to which humans are exposed is more than double the global average change, with temperatures rising 0.8°C versus 0.3°C.

Hugh Montgomery, co-chair of The Lancet Countdown on Health and Climate Change and director of the Institute for Human Health and Performance, University College London says: "Heat stress is hitting hard -- particularly amongst the urban elderly, and those with underlying health conditions such as cardiovascular disease, diabetes or chronic kidney disease. In high temperatures, outdoor work, especially in agriculture, is hazardous. Areas from Northern England and California, to Australia are seeing savage fires with direct deaths, displacement and loss of housing as well as respiratory impacts from smoke inhalation."

The report, which looks at 41 separate indicators across a range of themes, says urgent steps are needed to protect people now from the impacts of climate change. In particular, stronger labor regulations are needed to protect workers from extremes of heat and hospitals and the health systems we rely on need to be better equipped for extreme heat so they are able to cope. But the report also stresses that there are limits to adapting to the temperature increases, and if left unabated, climate change and heat will overwhelm even the strongest of systems, so the need for reducing greenhouse gas emissions is critical.

2018 has been an even hotter year in many parts of the world and the World Weather Attribution Study for northern Europe showed this summer's heat wave was twice as likely to have happened as a result of man-made climate change. Of the 478 global cities surveyed in the report, 51% expect climate change to seriously compromise their public health infrastructure.

"The world has yet to effectively cut its emissions. The speed of climate change threatens our, and our children's lives. Following current trends we exhaust our carbon budget required to keep warming below two degrees, by 2032. The health impacts of climate change above this level above this level threaten to overwhelm our emergency and health services," says Anthony Costello, co-chair of The Lancet Countdown.

Other findings of the report include: a new indicator mapping extremes of precipitation that identifies South America and southeast Asia among the regions most exposed to flood and drought and, on food security, the report points to 30 countries experiencing downward trends in crop yields, reversing a decade-long trend that had previously seen global improvement. Yield potential is estimated to be declining in every region as extremes of weather become more frequent and more extreme.