Study finds CO2 is greening the earth and making vegetation flourish worldwide | Western Standard | Lee Harding:
February 3, 2024 - "The world is growing greener and greener thanks to carbon emissions, researchers have found. The global greening continues despite increased drought stress since 2000 reads the article's title, published in Global Ecology and Conservation in January. The study, which was supported by the National Natural Science Foundation of China and the Postgraduate Research & Practice Innovation Program of Jiangsu Province, wanted a more accurate read following recent studies that found both greening and browning trends.
"'CO2 fertilization along with land management determined that greening is dominant. However, recently global browning signals due to drought stress have also been widely reported,' the researchers explained. 'We used the four latest leaf area index (LAI) datasets to explore this controversial topic, and found that global greening continued from 2001 to 2020. Greening acceleration occurred in 55.15% of the globe, while browning acceleration occurred in only 7.28%.' The accelerated greening was mainly concentrated in India and the European plains.
"The researchers, four of whom are affiliated with universities in China and one in Australia, said both climate change and carbon emissions were helping the greening and that in some places it was occurring despite drought.... 'Combined with meteorological variables, we found that CO2 change dominated the LAI trend, while climate change largely determined the LAI growth rate trend. Importantly, our study highlighted that drought trend did not necessarily trigger vegetation browning, but slowed down the rate of greening'....
"Vapor pressure deficit (VPD) is the difference between the amount of moisture that's actually in the air and the amount of moisture that air could hold at saturation. 'A growing body of research shows that vegetation growth is enhanced by moisture constraints due to increased VPD and decreased soil moisture caused by climate warming,' the researchers said. A 'drought trend could not lead to global browning as it could not overtake the positive effect of CO2 fertilization that contributed to global vegetation. Our study explains the rise in VPD offsets only a small fraction of the increase in productivity caused by warming and CO2 and gross primary productivity is still increasing globally.'
"Although the changes weren't uniform across the globe, positive trends dominated growth and acceleration of growth. This was borne out in two different kinds of analyses.
We counted areas with the consistent trend and growth rate trend in four LAI datasets, 60.29% of the areas in the globe were inconsistent, however in the consistent areas, 64.06% of the areas showed accelerated greening, mainly distributed in India, the European plain and East Africa. The areas that browning was accelerating was only 2.07% and most of them were distributed in Eastern area in Brazil....
We further took the mean of the four data sets as a reference and analyzed the trend and growth rate trend. Greening was accelerating in 55.15% of the globe, among which the greening acceleration of India and European plains was the most obvious, while the greening of China and North America plains was slowing down.
Only 14.44% of the globe was browning, with the accelerating (7.28%) and slowing down (7.16%) roughly equal.....
"The study is not the first to find potential upsides to climate change and carbon emissions. A 2018 study published in Nature found that global warming could make substantial new swaths of land able grow crops in the northern hemisphere, with Canada and Russia being the biggest winners."
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