Publikationsdatum:
2016-07-06
Beschreibung:
Wildfires pose a significant risk to human livelihoods and are a substantial health hazard due to emissions of toxic smoke. It is widely believed that climate change, through increasing the frequency of hot weather conditions, will also lead to an increase in wildfire activity. More recently, however, new research has shown that trends in population growth and urbanisation can be as important for fire prediction as changes in climate and atmospheric CO2, and that under certain scenarios, fire activity may continue to decline through most of the 21st century. The present study re-examines these results from the perspective of air pollution risk, focussing on emissions of airborne particulate matter (PM2.5). We combine an existing ensemble of simulations using a coupled fire-dynamic vegetation model with current observation-based estimates of wildfire emissions to predict future trends. Currently, wildfires PM2.5 emissions exceed those from anthropogenic sources in large parts of the world, while emissions from deforestation or peat fires constitute minor sources. We find that for Sub-Saharan Africa and southern China predictions of wildfire pollution risks depend almost entirely on population dynamics, whereas for North Australia and South America, it is mainly determined by climate change, with Southeast Asia lying somewhere in-between. Under a scenario of current legislation of anthropogenic emissions, global high population growth and slow urbanisation, wildfires may seize to be the dominant source in large parts of Sub-Saharan Africa. However, if anthropogenic emissions are strongly reduced, wildfires may both become the dominant source and lie above critical levels for health impacts in large parts of Australia, Africa, Latin America and Russia, and parts of southern China and southern Europe. This implies that controlling anthropogenic emissions will not suffice for attaining the World Health Organization air quality targets.
Digitale ISSN:
1680-7375
Thema:
Geologie und Paläontologie
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