by Desteny Alvarez, age 15 and posted with the permission of the Simpson Street Free Press
Droughts are estimated to become more common and extreme in many regions since global temperatures continue to rise. A recent study with NASA shows that land ecosystems have been slowly taking longer to recover from droughts in the 20th century, leading to tree death and increased greenhouse gas emissions.
A study team led by Christopher Schwalm of Woods Hole Research Center, Falmouth, Massachusetts, which included a scientist from NASA's Jet Propulsion Laboratory, Pasadena, California, estimated the recovery times following droughts in different regions of the world. They used climate model predictions confirmed by observations on NASA's Terra satellite and ground measurements from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. Based on the data that they gathered, the researchers concluded that recovery from droughts took longer in all the regions they studied.
Schwalm mentioned that, in model projections which did not take on new greenhouse restrictions, the "Time between drought events will likely become shorter than the time needed for land ecosystems to recover from them."
"Using the vantage point of space, we can see all of Earth's forests and other ecosystems getting hit repeatedly and increasingly by droughts,” said Josh Fisher of JPL. "Some of these ecosystems recover, but, with increasing frequency, others do not. Data from our 'eyes' in space allow us to verify our simulations of past and current climate, which, in turn, helps us reduce uncertainties in projections of future climate."
Shorter time between droughts, combined with longer recovery periods from drought, can lead to the possibility of widespread tree death, reducing the ability of land areas to absorb carbon from the atmosphere.
[Sources: NASA; Woods Hole Research Center]