Ozone: The Invisible Enemy of the Rainforest
Ozone present in the upper atmosphere protects the earth from excess ultraviolet radiation. However, when it is close to the ground, it harms living organisms, including humans.
As scientists from the UK’s University of Exeter have just reported, ground-level ozone is limiting the growth of tropical forests. The decline has been estimated at an average of 5.1 percent.In some regions, such as Asia, a decrease of less than 11 percent was recorded.
Meanwhile, tropical forests are one of the main stores of carbon dioxide. – Tropical forests play a key role in absorbing the carbon dioxide we emit – emphasizes Dr. Alexander Cheesman, author of the work published in the journal “Nature Geoscience”.
– Our study shows that air pollution can threaten this critical mechanism. We estimate that ozone has prevented the absorption of 290 million tons of carbon per year since 2000. The cumulative loss is equivalent to a 17 percent reduction in atmospheric carbon removal by tropical forests since the beginning of this century. – adds the specialist.
The role of tropical forests in combating climate change
Scientists conducted experiments in which they measured the susceptibility of different tropical tree species to ozone, then fed the results into a computer model simulating global vegetation. As they explain, urbanization, industrialization, burning fossil fuels and wildfires have led to an increase in particles such as nitrogen oxides, which contribute to the formation of ozone.
– Ozone concentrations in the tropics will continue to rise due to increased emissions of these particles and changing atmospheric chemistry in a warming world. – warns study co-author Dr. Flossie Brown. – We found that areas of current and future forest restoration—critical areas for climate change mitigation—are disproportionately affected by the elevated ozone levels we describe. It is clear that air quality will continue to play an important, often overlooked role in how forests sequester and store carbon..
The solution is to work on protecting air quality, scientists emphasize. And they suggest that, among other numerous benefits, it will benefit tropical forests.
