Over 77% of Earth's land became drier in last 30 years, warns UN report

Over 77 per cent of Earth's land experienced a drier climate during the three decades leading up to 2020, compared to the previous 30-year period, according to a report released by the UN Convention to Combat Desertification (UNCCD) on Monday.

During the same period, global drylands expanded by approximately 4.3 million square kilometres an area nearly a third larger than India now covering more than 40 per cent of the Earth's land.

The report, launched at the 16th conference of the UNCCD in Riyadh, Saudi Arabia, warned that if efforts to curb greenhouse gas emissions fail, another 3 per cent of the world's humid areas are projected to transform into drylands by the end of this century.

Meanwhile, the number of people living in drylands has doubled to 2.3 billion over the past three decades. Models suggest that as many as 5 billion could inhabit drylands by 2100 in a worst-case climate change scenario.

These billions of people face even greater threats to their lives and livelihoods from climate-related increases in aridification and desertification, the report said.

Areas particularly hard-hit by the drying trend include around 96 per cent of Europe, parts of the western US, Brazil, Asia, and central Africa.

South Sudan and Tanzania have the largest percentage of land transitioning to drylands, with China experiencing the largest total area shifting from non-drylands to drylands, the report said.

About half of the world's dryland inhabitants are located in Asia and Africa. The most densely populated drylands are in California, Egypt, eastern and northern Pakistan, large parts of India, and northeastern China.

In high greenhouse gas emissions scenarios, dryland expansion is forecast for the Midwestern United States, central Mexico, northern Venezuela, northeastern Brazil, southeastern Argentina, the entire Mediterranean region, the Black Sea coast, large parts of southern Africa, and southern Australia.

"This analysis finally dispels an uncertainty that has long surrounded global drying trends. For the first time, the aridity crisis has been documented with scientific clarity, revealing an existential threat affecting billions around the globe," said Ibrahim Thiaw, UNCCD Executive Secretary.

"Unlike droughts -- temporary periods of low rainfall -- aridity represents a permanent, unrelenting transformation, he added.

"Droughts end. When an area's climate becomes drier, however, the ability to return to previous conditions is lost. The drier climates now affecting vast areas across the globe will not return to how they were, and this change is redefining life on Earth," Thiaw said.