Less vegetation is appearing in countries that need it most

A new study from the University of Copenhagen confirms that climate change is disproportionately impacting different parts of the world. Across the world’s arid regions, the researchers discovered a concerning pattern, with less vegetation appearing in developing countries and more appearing in wealthier countries.

“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,” said study co-author Professor Rasmus Fensholt. 

Over 40 percent of the world’s ecosystems are arid and this percentage is expected to increase in the coming decades. In these dry areas, vegetation and other wildlife have adapted to survive with only scarce amounts of water, but they are also extremely vulnerable to climate change.

The researchers analyzed 15 years of satellite observations of vegetation and rainfall. To compare the evolution of vegetation in dry regions on a global scale, the team produced a calculation that accounts for the uneven distribution of rainfall. 

“Here, our results demonstrate that in arid regions, particularly those in Africa and Asia, less vegetation grows for the amount of rainwater that falls, while more vegetation grows in arid areas of South America and Australia,” said study lead author Christin Abel.

The experts noted that there could be several explanations for why climate change and rising global temperatures are impacting vegetation in arid regions of the world’s poorest countries, with rapid population growth being the most obvious. In Africa, for example, using unsuitable land for agriculture produces lower yields and puts increasing pressure on ecosystems that are already stressed.

In wealthier countries, arid regions are much better equipped to face climate change. There are more economic resources to support efficient systems for irrigation and fertilization to maintain large farms.

For the poorest areas of the world, the future trends are only going to get worse. As the arid regions expand, and vegetation becomes less abundant, there could be major food shortages and growing numbers of climate refugees.

Satellite imagery has actually shown that the world’s arid regions have become greener in recent years, but the amount of vegetation that is appearing in developing countries does not match the amount of rainfall.

“We have been pleased to see that, for a number of years, vegetation has been on an upwards trend in arid regions,” said Professor Fensholt. “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.”

“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.”

The study is published in the journal Nature Sustainability.

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By Chrissy Sexton, Earth.com Staff Writer