Please go to: doi.org or SCI-HUB (enter doi number, read info).
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The biosphere is far more effective at CO2 removal than has been heretofore assumed. It is not widely known, for example, that the continents of Australia and South America are net CO2 sequestrators [1]. This is a result returned by the Japanese GOSAT mission [2].
But the trees do more, far more than just absorbing CO2. They emit complex organics into the atmosphere, which assist in cloud formation, which, in turn, cools the globe by increasing its albedo [3].
[1] doi:10.1260/0958-305X.26.3.457 (Energy & Environment, May 2015)
[2] disq.us
[3] doi:10.1038/nature13032 (Nature, February 2014)
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Why capture and eliminate CO2, at a considerable expense, what is of such tremendous benefit to nature and to us [1-5], while having no observed detrimental effect [6-8] ???
[1] doi:10.1111/ele.12767 (Ecology Letters, May 2017)
[2] doi:10.1038/ncomms13428 (Nature Communications, November 2016)
[3] doi:10.1088/1748-9326/11/8/084001 (Environmental Research Letters, July 2016)
[4] doi:10.1016/j.rse.2016.01.001 (Remote Sensing and Environment, April 2016)
[5] doi:10.1038/nclimate3004 (Nature Climate Change, April 2016)
[6] doi:10.1016/j.grj.2017.08.001 (GeoResJ, December 2017)
[7] doi:10.3103/S1062873817020411 (Bulletin of the Russian Academy of Sciences: Physics, February 2017)
[8] doi:10.1007/s00376-017-6238-8 (Advances in Atmospheric Sciences, August 2017)
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Is there is a "right amount" of atmospheric CO2 or rate of accumulation of atmospheric CO2 ???
Yes, there is "a wrong amount," and it is "too little of it," when the atmospheric CO2 concentration drops below the starvation level for the biosphere, which is between 180 and 200ppm [1,2].
The catastrophic decline of the atmospheric CO2 concentration over the past 65 million years [3,4] has brought life on earth to near extinction.
We're really doing nature a big favor by taking carbon trapped under ground, burning it and returning it back to the atmosphere, where it belongs.
In turn, nature responds to our actions positively and exuberantly. There is much literature, based on satellite and other observations, that confirms this. Too much to cite here. Global Greening is in full swing. For some of the latest results see [5].
[1] doi:10.1111/j.1469-8137.2010.03441.x (New Phytologist, 2010)
[2] doi:10.1073pnas.0408315102 (PNAS, January 2005)
[3] doi: 10.1098/rstb.1998.0198 (Philosophical Transactions of the Royal Society of London, B, Biological Sciences, 1998)
[4] doi:10.1073pnas.022055499 (PNAS, April 2002)
[5] doi:10.1016/j.ecolind.2017.01.021 (Ecological Indicators, May 2017)
The average atmospheric residence time of man-made CO2 is only about 4 years according to [1]. The same article finds that human contribution to the CO2 increase over the whole industrial era is 15% only. An earlier classic review paper by Essenheigh quoted the residence time of between 5 and 15 years [2] based, amongst other measurements, on the residence time of 14C injected by the atmospheric nuclear tests in the 1950s.
So human contribution is really rather small. Most of the rise in the atmospheric CO2 is due to the ocean and soil out gassing in response to the increased solar heating throughout the 20th century [3,4].
[1] doi:10.1016/j.gloplacha.2017.02.009 (Global and Planetary Change, May 2017, invited research article)
[2] doi:10.1021/ef800581r (Energy and Fuels, May 2009)
[3] doi:10.1051/0004-6361/201423391 (Astronomy and Astrophysics, L10, 2014)
[4] doi:10.1007/s11214-014-0074-2 (Space Science Reviews, August 2014)
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It is true, of course, that plants capture CO2, but unless the plant material is sequestered somehow, as in coal formation, does it eventually gets back into the atmosphere ???
No, not, as long as the average global bio-mass does not shrink.
Observe that we humans are ourselves an important and sizable part of the global bio-mass. The growing mass of humanity and the animals that we feed on sequester a lot of atmospheric CO2.
Another important sequestration channel is phytoplankton, which is the largest eater of atmospheric and surface-oceanic CO2.
As other ocean critters consume the phytoplankton, carbon migrates down the oceanic food chain to end at the bottom of the ocean eventually as calcite. Once there, it is out of the ocean/atmosphere system for good, until the ocean floor is pulled under a continental plate, which lets some of the carbon be recycled by volcanoes. However, this conveyor belt has been slowing down, since the Moon, that partly drives it through tidal interactions, has been moving away. In effect, we ended up with catastrophic CO2 impoverishment over the last 65 million years. See, e.g., [1]. Traces of CO2 starvation have been seen in pine trees recovered from California's La Brea tar pits [2].
[1] doi:10.1073pnas.022055499 (PNAS, April 2002)
[2] doi:10.1073/pnas.0408315102 (PNAS, January 2005) |
