The study, involving Professor David Frame from the School of Geography, Environment and Earth Sciences and Director of the Climate Change Research Institute, shows some parts of South America are projected to get wetter this century due to climate change, but then dry out again after 2100 as patterns of rainfall shift southwards.
Led by Dr Ed Hawkins at the University of Reading, the research shows that certain regions in South America will get considerably wetter as the 21st century progresses, as the effect of global warming pushes a tropical zone of heavy rain south, towards the equator.
This is expected to give northwestern South America, including parts of Venezuela and Columbia, 20–50% more summer rain on average than it currently gets.
But the zone of heavy rain is likely to continue moving south, leaving behind a drier zone after about 100 years: indeed some model projections suggest that certain regions might get less rain than now. Average temperatures, on the other hand, are expected to get hotter, with serious implications for people in the region, as well as plant and animal life.
This ‘wetter, then drier’ pattern is likely to present a considerable challenge to planners, farmers, and ecosystems, which may have to deal with a climate shifting in two different directions over time.
Professor Frame says, “Generally, economic models of climate change assume quite simple and constant relationships between rainfall and temperature. This research demonstrates the limits of these assumptions.”
Read the full journal article Wetter then drier in some tropical areas on the Nature climate change website.