Global warming will cause ecosystems to produce more methane than first predicted

Date:
June 29, 2020
Source:
Queen Mary University of London
Summary:
New research suggests that as the Earth warms natural ecosystems
such as freshwaters will release more methane than expected from
predictions based on temperature increases alone.



FULL STORY ==========================================================================
New research suggests that as the Earth warms natural ecosystems such
as freshwaters will release more methane than expected from predictions
based on temperature increases alone.


==========================================================================
The study, published today in Nature Climate Change, attributes this
difference to changes in the balance of microbial communities within
ecosystems that regulate methane emissions.

The production and removal of methane from ecosystems is regulated by
two types of microorganisms, methanogens -- which naturally produce
methane -- and methanotrophs that remove methane by converting it into
carbon dioxide.

Previous research has suggested that these two natural processes show
different sensitivities to temperature and could therefore be affected differently by global warming.

Research led by Queen Mary University of London and the University
of Warwick studied the impact of global warming on freshwater
microbial communities and methane emissions by observing the effect of experimental warming of artificial ponds over 11 years. They found that
warming produced a disproportionate increase in methane production over
methane removal, resulting in increased methane emissions that exceeded temperature-based predictions.

Professor Mark Trimmer, Professor of Biogeochemistry at Queen Mary, said:
"Our observations show that the increase in methane emissions we see is
beyond what you could predict based on a simple physiological response
to the temperature increase. Long-term warming also changes the balance
in the methane-related microbial community within freshwater ecosystems
so they produce more methane while proportionately less is oxidised to
carbon dioxide. As methane is a far more potent greenhouse gas than carbon dioxide, together these effects increase the global warming potential
of the carbon gases released from these ecosystems." The experimental observations were supported by a meta-analysis of available data on
methane emissions collected from wetlands, forests and grasslands
worldwide, which showed that naturally warmer ecosystems also produce disproportionately more methane.

Professor Trimmer, said: "Our findings fit with what we see in the real
world for a wider variety of ecosystems. Together these results suggest
that as Earth temperatures increase through global warming, natural
ecosystems will continually release more methane into the atmosphere."
Dr Kevin Purdy, Associate Professor of Microbial Ecology at Warwick,
added: "Our studies have led to a better understanding of how global
warming can affect methane emissions from freshwaters. This means that
future predictions of methane emissions need to take into account how ecosystems and their resident microbial communities will change as
the planet warms." Methane is a powerful greenhouse gas with some 28
times the global warming potential of carbon dioxide over a 100 year
period. Over 40 per cent of methane is released from freshwaters such
as wetlands, lakes and rivers making them a major contributor to global
methane emissions.


========================================================================== Story Source: Materials provided by Queen_Mary_University_of_London. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Yizhu Zhu, Kevin J. Purdy, O"zge Eyice, Lidong Shen, Sarah F.

Harpenslager, Gabriel Yvon-Durocher, Alex J. Dumbrell, Mark Trimmer.

Disproportionate increase in freshwater methane emissions induced
by experimental warming. Nature Climate Change, 2020; DOI:
10.1038/s41558- 020-0824-y ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/06/200629120210.htm

--- up 22 weeks, 6 days, 2 hours, 38 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)