With CO2 Levels Rising, Drylands Are Turning Green – Yale E360

Recent studies indicate that many of the world's drylands are experiencing unexpected greening despite rising CO2 levels and increasing aridity. This phenomenon is attributed primarily to a 50% increase in atmospheric carbon dioxide since preindustrial times, which enhances photosynthesis and allows plants to use water more efficiently. Regions such as Southeast Australia, the Sahel in Africa, and parts of India and China are witnessing this trend, where vegetation is expanding rather than declining as previously predicted.

While the greening effect is significant, scientists caution that it may have negative consequences for local ecosystems and water supplies, as increased vegetation can deplete scarce water resources. Drylands, which cover about 40% of the Earth's land surface and are home to over a third of the global population, have historically been thought to be at risk of desertification due to climate change and human activities. However, recent assessments show that only about 6% of drylands have experienced desertification since 1982, while 41% have seen significant greening.

The implications of this greening are complex; while it may help mitigate some effects of climate change by increasing carbon capture, it also poses challenges for water management and biodiversity. Future projections suggest that this trend of greening in drylands is likely to continue, driven by ongoing increases in CO2 levels, although local land management practices will also play a crucial role in determining the extent of vegetation growth.