US desert grassland collapse is linked to changes in the Pacific Ocean
The Glass mountains in the northern tip of the Chihuahuan desert
Luc Novovitch/Alamy
For much of the 20th century, boom and bust cycles of desert grasses in the US Southwest were linked to long-term cycles of temperature in the Pacific Ocean. That link now appears to have been broken, possibly due to climate change. This could complicate efforts to restore grasslands that support biodiversity and grazing livestock.
The Chihuahuan desert extends from the US Southwest into Mexico over more than 500,000 square kilometres. It contains some of the most biodiverse grasslands on …