Soil microbes accelerate global warming

More carbon dioxide in the atmosphere causes soil to release the potent greenhouse gases methane and nitrous oxide, new research published in this week's edition of Nature reveals. "This feedback to our changing atmosphere means that nature is not as efficient in slowing global warming as we previously thought," said Dr Kees Jan van Groenigen, Research Fellow at the Botany department at the School of Natural Sciences, Trinity College Dublin, and lead author of the study.

Van Groenigen, along with colleagues from Northern Arizona University and the University of Florida, gathered all published research to date from 49 different experiments mostly from North America, Europe and Asia, and conducted in forests, , wetlands, and , including rice paddies. The common theme in the experiments was that they all measured how extra in the atmosphere affects how soils take up or release the gases methane and .

The research team used a called , or quantitative data synthesis, a powerful tool for finding general patterns in a sea of conflicting results. "Until now, there was no consensus on this topic, because results varied from one study to the next," explained Professor Craig Osenberg of the University of Florida and co-author of the study. "However, two strong patterns emerged when we analysed all the data: firstly more CO2 boosted soil emissions of nitrous oxide in all the ecosystems, and secondly, in rice paddies and wetlands, extra CO2 caused soils to release more methane." Wetlands and rice fields are two major sources of to the atmosphere.

The culprits are specialised in soil, that respire the chemicals nitrate and carbon dioxide, like humans respire oxygen. The microbes also produce methane, a 25 times more powerful than carbon dioxide, and nitrous oxide, 300 times more potent than carbon dioxide. Their oxygen-free habit is one of the reasons these microorganisms flourish when atmospheric carbon dioxide concentrations increase. Van Groenigen explained: "The higher CO2 concentrations reduce plant water use, making soils wetter, in turn reducing the availability of oxygen in soil, favoring these microorganisms."

The other reason these microorganisms become more active is that increasing CO2 makes plants grow faster, and the extra plant growth supplies soil microorganisms with extra energy, pumping up their metabolism. This extra plant growth is one of the main ways ecosystems could slow climate change. With more CO2, plants grow more, soaking up carbon dioxide through photosynthesis, and, the hope is that they also lock away carbon in wood and soil. But this new work shows that at least some of that extra carbon also provides fuel to microorganisms whose byproducts, nitrous oxide and methane, end up in the atmosphere and counteract the cooling effects of more plant growth.

"It's an ecological point and counterpoint: the more the plants soak up CO2, the more microbes release these more potent greenhouse gases," said Bruce Hungate, Professor at Northern Arizona University and co-author on the study. "The microbial counterpoint is only partial," continued Hungate, "reducing the cooling effect of plants by about 20%."

But it's an ecological surprise, too, and one that climate models will need to reckon with as they further refine pictures of the climate of the future. "By overlooking the key role of these two greenhouse gases, previous studies may have overestimated the potential of ecosystems to mitigate the greenhouse effect," van Groenigen concluded.


Explore further

How grazing lands influence greenhouse gas

More information: Van Groenigen, K.J., et al. (2011) 'Increased soil emissions of potent greenhouse gases under increased atmospheric CO2'. Nature, published 14 July. DOI: 10.1038/nature10176
Citation: Soil microbes accelerate global warming (2011, July 13) retrieved 23 August 2019 from https://phys.org/news/2011-07-soil-microbes-global.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
0 shares

Feedback to editors

User comments

Jul 13, 2011
Is this science or propaganda?

Is there a connection between:

a.) Hiding and manipulating data on the Sun - Earth's heat source,
b.) The world-wide fable of CO2-induced global warming,
c.) Disintegration of the USA space program,
d.) Disintegrating of the world's economy,
e.) Loss of national sovereignty, and
f.) Budget negotiations!

Are these a coincidence?

No. They follow from a 1972 decision to use "Global Climate Change" as the common enemy to unite nations, end nationalism, and avoid the threat of nuclear annihilation.

Many climate skeptics endorse those noble goals, but not the use of science as a propaganda tool that might lead to the tyrannical world government in George Orwell's book, "1984".

http://www.online...ll/1984/

Do you see the connection [1]?

1. Dark Fireworks on the Sun, by Dr. Tony Phiilips

www.physorg.com/n...sun.html

With kind regards,
Oliver K. Manuel
Former NASA PI for Apollo

Jul 13, 2011
Again. Reported for spaming the SAME POST across multiple articles regardless of topic.

Please stop your nonsense.

Jul 13, 2011
Please stop your nonsense.


I regret that opinions, based on space science observations since 1960, annoy you.

Why do you think there is no connection between:

a.) Misinformation on the Sun - Earth's heat source,
b.) The fable of CO2-induced global warming,
c.) Dismantling of the USA space program,
d.) Disintegrating of national economy,
e.) Loss of national sovereignty, and
f.) Fiscal decline in the the USA?

Isn't economic collapse, indebtedness to the World's Bank, and servitude to a tyrannical world government far more probable now than CO2-induced global warming?

See these papers on Earth's climate:

"Super-fluidity in the solar interior: Implications for solar eruptions and climate", JOF 21, 193 (2002):

http://arxiv.org/.../0501441

"Earth's Heat Source - The Sun", E & E 20, 131 (2009):

http://arxiv.org/pdf/0905.0704

"Neutron Repulsion", APEIRON J., in press, 19 pages (2011):

http://arxiv.org/...2.1499v1


Jul 14, 2011
Mr Manuel,

I have seen your posts over the last year continously repeating the same papers about the sun, neutron repulsion, the sun, and your Pres eisenhower quotes posted over and over.

They're always the same. You always point at the scientific elite trying to control everything. I'm quite tired of it.

I'm an engineer in the aerospace industry and sadly, am very aware of the declining space program.

What annoys me in your post is that you do NOT represent "space science observation." You represent your point of view which I actually respect. I simply do not want to have to read it over and over and over and over every day.

This article was about soil bacteria increasing CO2 output. Regardless of wherever you are for / against / dont care about the climate, we could at least discuss the paper.

But no you always choose to repeat the same lines which gets tiresome. So yes, I will continue to report your posts until you actually contribute to the discussion AT HAND.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more