Researchers from the University of Copenhagen have been closely following vegetation trends across the globe’s driest areas using satellite imagery from over the years, and they have discovered a disturbing trend: Too little vegetation is sprouting up from rainwater in developing nations, whereas things are headed in the opposite direction in wealthier ones. This could result in future food shortages and growing numbers of climate refugees.
Over 40% of the earth’s ecosystems are arid, with this percentage likely to significantly increase over the course of the 21st century. A few of these areas, like those in Australia and Africa, might be desert or savannah, where sparse rainfall has long been the norm. Within these biomes, wildlife and vegetation have long adapted to their dearth of water resources, however, they are extraordinarily vulnerable to climate change.
Utilising extensive imagery from satellites which monitor the earth daily, researchers from the University of Copenhagen’s Department of Geosciences and Natural Resources Management have studied the evolution of vegetation in arid regions. They have reached an unequivocal conclusion:
“We observe a clear trend of arid areas developing in a negative direction in the most economically challenged countries. Here, it is apparent that the growth of vegetation has become increasingly decoupled from the water resources available and that there is simply less vegetation in relation to the amount of rainfall. The opposite is the case in the wealthiest countries,” stated Professor Rasmus Fensholt of the Department of Geosciences and Natural Resource Management.
According to the researchers, there might be more than just a single explanation as to why rising global temperatures and climate change are significantly impacting vegetation in arid regions of the globe’s poorest nations. One of the most obvious reasons is rapid population growth, in Africa, for instance, where there seems to be an increasing need to exploit land that is inadequate for agriculture. This results in lower yields and placing increasing amounts of livestock on too little grass in already fragile ecosystems.
Alternatively, vegetation in arid areas of the globe’s richer nations appears to cope better with the effects of climate change. This could be down to the intensification and expansion of larger farms, where more economic resources allow for, among other things, irrigation and fertilization.
Due to climate change, the future trends of the globe’s poorest regions will appear to get worse. Forecasts have pointed to an expansion of the arid areas as we know today, growing in size. They are bound to become a larger share of the world’s ecosystems. This could result in an increase of people being without food and having to migrate.
“One consequence of declining vegetation in the world’s poorer arid regions areas may be an increase in climate refugees from various African countries. According to what we’ve seen in this study, there is no indication that the problem will diminish in the future,” explains Rasmus Fensholt.
For quite a number of years, satellite imagery has enabled researchers to understand that, overall, it does appear that the arid regions around the world have become greener, however, when researchers look closer at the amount of vegetation arid areas in developing nations have gotten in relation to the amount of rainfall, the narrative changes.
“We have been pleased to see that, for a number of years, vegetation has been on an upwards trend in arid regions. But if we dig only a tiny bit deeper and look at how successfully precipitation has translated into vegetation, then climate change seems to be hitting unevenly, which is troubling,” says Rasmus Fensholt.
As reported by Sciencecodex
