Image copyright WWF Image caption Cyclone Phailin hit the Sri Lankan coast in November 2016
Warnings of a rise in the damage done by tropical cyclones in the region will be doubled by the end of the century, a new study suggests.
If current global warming trends continue and pollution continues to increase, 20% of the world’s coastlines could be exposed to a twice-as-powerful storm by 2100.
Scientists say the findings could have a “dangerous impact” on coastal communities.
Another team of scientists says global warming and pollution are likely to lower global temperatures by 0.5C this century.
Strong storms can cause both physical and economic damage, with the buildings, infrastructure and crops of the countries which are most exposed to these storms most likely to be damaged.
Image copyright EPA Image caption Cyclone Pam smashed through Vanuatu in April 2014
Cyclone Pam in 2014 devastated the small island state of Vanuatu, destroying much of the country’s infrastructure and killing 22 people.
Other global hurricanes and typhoons have also caused severe destruction, in a region where up to 10 million people have built their homes directly on the coast, an area in which the risk of storm surges is particularly high.
‘Higher intensity’
Image copyright Reuters Image caption Building on the strong data base of weather and climate data set up by scientists from the University of Melbourne, the group was led by Dr James Overland
The team of researchers from universities in Australia, South Korea and the UK analysed the records of about a quarter of a million storms, which were gathered by NASA’s Jet Propulsion Laboratory (JPL) over the past decade.
They found that the amount of wind energy generated by a storm could double in some countries if current global warming trends continue and pollution continues to increase.
“If we remain on the current emissions path and the pollution continues to increase, you’re looking at a doubling of the population in exposure to storm winds,” said Dr James Overland, from Australia’s University of Melbourne, who led the team.
If climate change affects rainfall patterns more and warmer ocean temperatures increase storm speed and strength, then we’re also likely to see heavier storms. Dr James Overland
Storm surges could be more powerful, as well as more frequent, and the regional danger would spread to wider parts of the world.
“We’re trying to understand how climate change will interact with weather to reduce the threat of storm-driven damage,” said Dr Overland.
“Because we use a growing database of storms to analyse the impact of climate change, that gives us a good benchmark of what’s happening,” he said.
Climate change and pollution may also, the study suggests, lead to less rain that is falling in the Pacific. This would mean that tropical cyclones – which are more likely to have higher winds and higher tides – will have more powerful storm surges.
“If climate change affects rainfall patterns more and warmer ocean temperatures increase storm speed and strength, then we’re also likely to see heavier storms,” said Dr Overland.
“There’s a real worry that we could have climate change caused by the pollution and that could turn into huge cyclones.”
Image copyright Jaymilesh Maruthu Image caption Phailin (above) was one of the strongest cyclones to hit the Indian Ocean
Meanwhile, a third study in The American Journal of Physical Science says global temperatures will fall by 0.5C this century.
The scientists say the effects of fossil fuel use over the past century will probably drive global temperatures up by between 2C and 4C, which is what most climate models are assuming.
“However, we have observed global greenhouse gas concentrations going up by nearly 75% in the past 200 years,” said Dr Gary Yohe, a co-author of the study from the Lambert School of Environment at King’s College, London.
“It is likely that existing warming is already affecting the climate system.
“Because emissions of greenhouse gases continue to rise, these warming effects can compound in the future.”
This means global average temperatures will continue to rise well beyond the end of the century, he said.
“Therefore the world faces a rising temperature, but it will not follow a particular pattern.”