New research has painted a grim picture of a world suffering the effects of runaway climate change in which the rich get richer and the poor even poorer.
While most research to date on the economic impacts of rising temperatures has focused on impacts to particular industries, scientists at the University of Arizona took a "top-down" approach, looking instead at the relationship between temperatures and a country or region's economic output.
"Combining the latest physical climate models, socioeconomic projections and economic estimates of past impacts, we find that future warming could raise the expected rate of economic growth in richer countries, reduce the expected rate of economic growth in poorer countries, and increase the variability of growth by increasing the climate's variability," Derek Lemoine and Sarah Kapnick write in the latest issue of Nature Climate Change.
Over a decade, their modelling showed each degree the mean temperature rises equates to an economic boost of between 1 and 3 percent for much of the world – but not in south Asia and sub-Saharan Africa, where much of the world's poverty is found.
"Global warming has heterogeneous climatic manifestations across these countries, but its effects on any given country's market output are primarily determined by that country's income level," the researchers write. "Richer countries' economies can benefit from warming, even as poorer countries are harmed."
In a separate study, scientists in Australia claim climate change will lead to "extreme" El Niño and La Niña events, resulting in more frequent floods and droughts.
In an El Niño phase, Pacific waters are warmer than usual, and in a La Niña, they're colder.
"Accelerated equatorial Pacific warming, particularly in the east, is expected to induce extreme rainfall in the eastern equatorial Pacific and extreme equatorward swings of the Pacific convergence zones, both of which are features of extreme El Niño.
"The frequency of extreme La Niña is also expected to increase in response to more extreme El Niños, an accelerated maritime continent warming and surface-intensified ocean warming."