Freshwater lakes already emit a quarter of global CO2, say researchers

Posted: November 21, 2019 by oldbrew in Carbon cycle, Emissions, Natural Variation, research
Tags: ,

The carbon cycle [credit:]

This seems to be underlining the futility of pretending that humans could somehow control or manage nature’s carbon cycle, to satisfy a strange ‘greenhouse gas’ obsession.

Lakes and ponds are the final resting place for many of the Earth’s plants. Rivers collect much of the planet’s dead organic matter, transporting it to rest in calmer waters, says

But on a microscopic scale, lakes are anything but calm. An invisible metropolis of microbes feeds on these logs and leaves, producing greenhouse gases as a byproduct.

As a result, lakes may be responsible for as much as a quarter of the carbon in the atmosphere—and rising.

New research conducted with my colleagues in Cambridge, Germany and Canada suggests that emissions from freshwater lakes could double in the coming decades because of climate change.

All known life on Earth is made of carbon. When plants and animals reach the end of their lives, microorganisms such as bacteria and fungi come to feast. They feed on the carbon-based remains of other organisms and their waste products—collectively known as organic matter.

As a byproduct of this never-ending feast, microbes release gases such as carbon dioxide and methane into the environment. While each individual microbe releases a minuscule amount of gas, they are the most abundant organisms on Earth, so it adds up.

Energy from sunlight can also break the chemical bonds between molecules of organic matter, releasing smaller molecules, such as carbon dioxide, into the environment.

Some of this degradation happens on the forest floor. But much of the organic matter that falls to the ground ends up in the water. Winds, rain and snow transport it into lakes, or more often into the rivers that feed them.

The amount of greenhouse gases released from lakes by microbes and sunlight is huge. Initial estimates were about 9% of the net carbon released from the Earth’s surface to the atmosphere—that is, the amount released over and above the Earth’s carbon-storing processes.

But, thanks to improved measurements, recent research has revised the figure to as high as 25%. These numbers are substantial given that that lakes only comprise about 4% of the global land surface.

In the coming years, lakes will receive more and more organic matter for microbes to digest. A warming climate will bring more forest cover around lakes and a greater proportion of broad-leaved trees, such as maples and oaks, as compared to needle-leaved trees, such as pines.

Carbon in a thousand forms

To understand how changes to forests will alter the role that lakes play in the carbon cycle, we performed an experiment in two Canadian lakes.

Continued here.
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Research paper: Chemical and microbial diversity covary in fresh water to influence ecosystem functioning [Nov. 2019]

  1. Peter Stallwood says:

    Go round the marshes at Coulon in France and the boatman will stir up the silt and will light the methane, from rotting vegetation in the water, with his lighter.

  2. diogenese2 says:

    what is the source of all organic carbon but atmospheric CO2? Therefore climate change Ie global warming is increasing the capture of atmospheric CO2 and its subsequent release back. Therefore climate change is causing itself!
    I suppose that the study of cycles will always lead to a circular argument.

  3. Kip Hansen says:

    This study misses the Godzilla-in-the-room of CO2 emissions — THE OCEANS — where the same processes produce CO2 and Methane — biological activity. While freshwater lakes account for 4% of the Earth’s surface, and produce, according to this study, 25% of the newly emitted CO2, the oceans account for 70% of the Earth’s surface (and orders of magnitude more volume than lakes). If oceans and lakes are proportional in CO2 production, the oceans would be producing 17 times the amount of CO2 that lakes produce…..

    Much of the CO2 produced in the oceans remains dissolved in the sea water — until warming of the waters causes some of it to be released — a process that started hundreds of years ago.

  4. Jeremy says:

    ‘lakes may be responsible for as much as a quarter of the carbon in the atmosphere’

    may, could, possibly… It matters not. What’s now clear is that human emissions are much too small to be responsible for the increase of carbon in the atmosphere.

    This makes all of the green fanfare little more than virtue signalling – expensive virtue signally, paid for by the public.

  5. stpaulchuck says:

    just another confirmation bias “study” predicting doom, meh

    We come out of the LIA and gee golly the climate warms up. Estimates based on history indicate we are still a good degree cooler than pre-LIA so this warming is ordinary. Measurements and estimates say that Nature burps up about 96% to 97% of the Satanic Gases indicating there is little to nothing to be gained scientifically or economically from gutting our reliable power systems in favor of windmills, solar panels, and other low energy density and low reliability sources.

    Diogenes2 and Kip Hansen provide on target observations above.

    The idea that my F-150 and my backyard grill are going to cause catastrophic thermal runaway is ludicrous.

  6. oldbrew says:

    Ned Nikolov has also exposed the false logic behind CO2 theory.

  7. Gamecock says:

    ‘A warming climate will bring’

    No place on earth has a warming climate. None. Double ought zero.

  8. Chaswarnertoo says:

    My dear oldbrew, Spot on, as have the Drs Conolly in their massive radiosonde data analysis. Now, how do we get the gretins and politicos to understand?

  9. oldbrew says:

    As Prof. Ian Plimer points out, if the atmosphere contained ‘carbon’ we would have visibility problems since carbon is black.

  10. hunterson7 says:

    Years ago, before the consensus co-opted everything, I heard an interview with a limnologists who said that freshwater lakes absorbed nearly as much CO2 by way of sequestration as an ocean basin.
    The website link was lost a while ago. But the gistvwas that the CO2 obsessed should be happy. That of course is unacceptable to the consensus. Notice the framing in this article: focus on emissions only.