Will global warming lead to more droughts?
Many parts of the world seem to be experiencing droughts at a higher frequency. Could global warming and climate change be responsible for this?
While droughts can have different causes depending on the area of the world and other natural factors, many scientists have started finding correlations between intense droughts and climate change.
Some estimates even indicate that droughts may have doubled in frequency in the recent past due to global warming.
Like other types of extreme weather, drought is experienced when circulation patterns get ‘stuck’ in one formation, or push outside their normal bounds of variation. As temperatures remain high for a long time, soil moisture evaporates, causing an additional feedback and worsening the heat wave.
We most often think about drought in relation to (lack of) precipitation/rain. This is known as a meteorological drought, which is highly specific to a region as average precipitation may vary.
We can also think about hydrological drought, or how decreased precipitation affects streamflow, soil moisture, reservoir and lake levels, and groundwater recharge.
There is also the “agricultural drought” and “economic drought” which result from the inability to access water when needed rather than from the lack of water itself.
Global climate change affects a variety of factors associated with drought. There is high confidence that increased temperatures will lead to more precipitation falling as rain rather than snow, earlier snow melts, and increased evaporation and transpiration. All these affect not just the presence of water, but also its practical availability and access.
Thus, it can be said that global warming will likely increase the chances of not just meteorological drought, but also of hydrological and agricultural droughts. A real cause for concern!