Study: wettest or driest regions, deluges grow

Study: wettest or driest regions, deluges grow


A team of scientists led by Dr Markus Donat of the University of New South Wales in Sydney have written in the journal Nature Climate Change, “Extreme daily precipitation averaged over both dry and wet regimes shows robust increases” since 1950.

Projected climate change until 2100 indicated a “continued intensification of daily precipitation extremes”.

Dr-Markus-Donat-University-New-South-WalesReuters Newsagency reports the study examined trends in the driest 30 per cent of the Earth’s land area and the wettest 30 per cent.

Warm air can hold more moisture than cold.

Past studies have suggested that wet areas will get wetter and dry areas drier overall with a warming trend, blamed by scientists on man-made emissions of greenhouse gases.

However, there have been big uncertainties about how the frequency of local extremes of rainfall may change, from tropical forests in the Amazon to deserts.

US-Death-Valley-flowers-rainsAmong recent downpours, Death Valley in California, the hottest and driest place in North America, has had spectacular flowers this spring after heavy rains last year.

Reuters reports in 2015, Chile’s Atacama desert was carpeted in flowers after the heaviest rains in 20 years.

Extreme rains also cause damaging floods.

Australia-floods-2011Severe rainfall is especially a threat in dry areas, the study said, because authorities have often invested little in flood defences.

The study’s findings “do not tell us what will actually happen in any particular location, but rather how risks will change”, said Dr William Ingram, of Oxford University, who was not part of the study team.

China-desert-002In a commentary in Nature Climate Change he wrote that there were still big gaps in scientific understanding of rainfall and climate change.

There are few rain gauges in the Sahara, for instance.

Last December, 195 nations reached the United Nations sponsored Paris Agreement on climate change, aiming to shift from oil, coal and natural gas to low-emission renewable energies such as wind and solar power this century.