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https://www.reuters.com/business/environment/tropical-wetlands-are-releasing-methane-bomb-threatening-climate-plans-2024-11-17/>
'BAKU, Nov 17 (
Reuters) - The world's warming tropical wetlands are releasing
more methane than ever before, research shows — an alarming sign that the
world's climate goals are slipping further out of reach.
A massive surge in wetlands methane — unaccounted for by national emissions
plans and undercounted in scientific models — could raise the pressure on
governments to make deeper cuts from their fossil fuel and agriculture
industries, according to researchers.
Wetlands hold huge stores of carbon in the form of dead plant matter that is
slowly broken down by soil microbes. Rising temperatures are like hitting the
accelerator on that process, speeding up the biological interactions that
produce methane. Heavy rains, meanwhile, trigger flooding that causes wetlands
to expand.
Scientists had long projected wetland methane emissions would rise as the
climate warmed, but from 2020 to 2022, air samples showed the highest methane
concentrations in the atmosphere since reliable measurements began in the
1980s.
Four studies published in recent months say that tropical wetlands are the
likeliest culprit for the spike, with tropical regions contributing more than 7
million tonnes to the methane surge over the last few years.
"Methane concentrations are not just rising, but rising faster in the last five
years than any time in the instrument record," said Stanford University
environmental scientist Rob Jackson, who chairs the group that publishes the
five-year
Global Methane Budget, last released in September.
Satellite instruments revealed the tropics as the source of a large increase.
Scientists further analyzed distinct chemical signatures in the methane to
determine whether it came from fossil fuels or a natural source — in this case,
wetlands.
The Congo, Southeast Asia and the Amazon and southern Brazil contributed the
most to the spike in the tropics, researchers found.
Data published in March 2023 in
Nature Climate Change shows that annual
wetland emissions over the past two decades were about 500,000 tonnes per year
higher than what scientists had projected under worst-case climate scenarios.
Capturing emissions from wetlands is challenging with current technologies.
"We should probably be a bit more worried than we are," said climate scientist
Drew Shindell at Duke University.'
Via Susan ****
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
