Solar heating will also rise, causing more droughts in years to come
Climate scientists announced on Wednesday they had found evidence to back predictions for a future with lower average rainfall, even though Earth's past warming episodes had led to more precipitation, not less
.
Writing in the Nature journal, researchers said they had found proof that global warming caused by humans’ greenhouse-gas emissions has a different effect on rainfall than warming caused by increased solar radiation.
Warming induced by carbon emissions is expected to accompany a rise in droughts in the future, they said.
This runs contrary to experience during the so-called Medieval Warm Period, from 1000 to 1250 AD, when Earth was hotter than today as a result of solar heating - but also wetter.
Scientists have long battled to understand the apparent contradiction.
Now they have shown that the two causes induce warming in different regions of the atmosphere, with different outcomes for rainfall formation.
The introduction of heat-absorbing greenhouse gases leads to a narrowing of the usual temperature difference between different layers of the atmosphere - thus a more stable atmosphere that is less conducive to rain, said the report.
"For the same increase in temperature, solar heating will induce an overall higher level of rainfall than greenhouse gases," a Nature press statement said.
"Less rainfall [under the greenhouse-gas warming scenario] means on average increasing chances for droughts," said co-author Bin Wang of the University of Hawaii's International Pacific Research Center.
Solar radiation can be affected by factors like volcanic activity, the level of aerosols in the atmosphere and changes in the Earth's orbit around the Sun.
The study says the estimates for future rainfall are a global average, and do not apply to what is expected to happen locally.
Previous research has pointed to risks of regional flooding or water stress as climate change alters traditional winds and the amount of moisture they pick up at sea.
Source: AFP
GMT 10:53 2018 Tuesday ,23 January
Philippine volcano rains ash, violent eruption fearedGMT 05:10 2018 Monday ,22 January
China's waste import ban upends global recycling industryGMT 09:15 2018 Sunday ,21 January
Dutch shocked by call to ban EU electric pulse fishingGMT 08:03 2018 Friday ,19 January
Cape Town water ration to be slashed as drought bitesGMT 08:06 2018 Thursday ,18 January
Thames paddle-boarders try to turn the tide on plasticGMT 11:22 2018 Wednesday ,17 January
The Romanian sheep nibbling away at US securityGMT 08:02 2018 Tuesday ,16 January
China races to prevent environmental disasterGMT 07:58 2018 Sunday ,14 January
Sea levels off Dutch coast highest ever recordedMaintained and developed by Arabs Today Group SAL.
All rights reserved to Arab Today Media Group 2021 ©
Maintained and developed by Arabs Today Group SAL.
All rights reserved to Arab Today Media Group 2021 ©
Send your comments
Your comment as a visitor