There have been significant wildfires in Chile since November, and they continue. These are the worst fires Chile has seen in known history, and Chile has been keeping track of its history for quite a while.
Are these fires climate change caused? Apparently so. Chile has had a rain deficit for well over a decade, though it as been extra dry for about five years. Drought experts call it a “mega-drought.” Droughts tend to have climate change links, and this one is no exception. A study from just one year ago links anthropogenic climate change to the drought.
Within large uncertainties in the precipitation response to greenhouse gas forcing, the Southeast Pacific drying stands out as a robust signature within climate models. A precipitation decline, of consistent direction but of larger amplitude than obtained in simulations with historical climate forcing, has been observed in central Chile since the late 1970s. To attribute the causes of this trend, we analyze local rain gauge data and contrast them to a large ensemble of both fully coupled and sea surface temperature-forced simulations. We show that in concomitance with large-scale circulation changes, the Pacific Decadal Oscillation explains about half of the precipitation trend observed in central Chile. The remaining fraction is unlikely to be driven exclusively by natural phenomena but rather consistent with the simulated regional effect of anthropogenic climate change. We particularly estimate that a quarter of the rainfall deficit affecting this region since 2010 is of anthropogenic origin. An increased persistence and recurrence of droughts in central Chile emerges then as a realistic scenario under the current socioeconomic pathway.
Heat on top of the drought adds to the likelihood of fires. Decreased snow pack from reduced rainfall and increasing temperatures at altitude also contribute.
Here is the Climate Signals attribution schematic for this event. Click through to climate signals for more.
Published at Thu, 02 Feb 2017 22:35:27 +0000