Scientists have predicted that droughts and floods will become more frequent and severe as our planet warms and climate changes, but detecting this on regional and continental scales has proven difficult.
Scientists have predicted that droughts and floods will become more frequent and severe as our planet warms and climate changes, but detecting this on regional and continental scales has proven difficult. Now a new NASA-led study confirms that major droughts and pluvials – periods of excessive precipitation and water storage on land – have indeed been occurring more often.
In the study published March 13, 2023, in the journal Nature Water, two NASA scientists examined 20 years of data from the NASA/German GRACE and GRACE-FO satellites to identify extreme wet and dry events. Floods and droughts account for more than 20% of the economic losses caused by extreme weather events in the U.S. each year. The economic impacts are similar around the world, though the human toll tends to be most devastating in poor neighborhoods and developing nations.
The scientists also found that the worldwide intensity of these extreme wet and dry events – a metric that combines extent, duration, and severity – is closely linked to global warming.
From 2015-2021 – seven of the nine warmest years in the modern record – the frequency of extreme wet and dry events was four per year, compared with three per year in the previous 13 years. This makes sense, say the authors, because warmer air causes more moisture to evaporate from Earth's surface during dry events; warm air can also hold more moisture to fuel severe snowfall and rainfall events.
Read more at NASA
Image: Global shallow groundwater from 2003 to 2021. (Credits: NASA)
