Understanding how the emergence of the anthropogenic warming signal from the noise of internal variability translates to changes in extreme event occurrence is of crucial societal importance. By utilising simulations of cumulative carbon dioxide (CO2) emissions and temperature changes from eleven earth system models, we demonstrate that the inherently lower internal variability found at tropical latitudes results in large increases in the frequency of extreme daily temperatures (exceedances of the 99.9th percentile derived from pre-industrial climate simulations) occurring much earlier than for mid-to-high latitude regions. Most of the world's poorest people live at low latitudes, when considering 2010 GDP-PPP per capita; conversely the wealthiest population quintile disproportionately inhabit more variable mid-latitude climates. Consequently, the fraction of the global population in the lowest socio-economic quintile is exposed to substantially more frequent daily temperature extremes after much lower increases in both mean global warming and cumulative CO2 emissions.
New Zealand Climate Change Research Institute, School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington 6012, New Zealand;New Zealand Climate Change Research Institute, School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington 6012, New Zealand;National Institute of Water and Atmospheric Research, Wellington 6021, New Zealand;Institute for Atmospheric and Climate Science, ETH Zürich, Universitätstrasse 16, CH-8092 Zürich, Switzerland;National Centre for Atmospheric Science, Department of Meteorology, University of Reading, Reading RG6 6BB, UK;Climatic Research Unit, School of Environmental Sciences, University of East Anglia, Norwich, UK;Met Office Hadley Centre, FitzRoy Road, Exeter EX1 3PB, UK
Recommended Citation:
Luke J Harrington,David J Frame,Erich M Fischer,et al. Poorest countries experience earlier anthropogenic emergence of daily temperature extremes[J]. Environmental Research Letters,2016-01-01,11(5)