Press Release 13-139
Seasonal carbon dioxide range expanding as more is added to Earth’s atmosphere
Northern Hemisphere land-based ecosystems “taking deeper breaths,” scientists find
![co2_weekly_mlo[1]](http://wattsupwiththat.files.wordpress.com/2013/08/co2_weekly_mlo1-e1376168771698.png?resize=640%2C464)
Levels of carbon dioxide in the atmosphere rise and fall each year as plants, through photosynthesis and respiration, take up the gas in spring and summer, and release it in fall and winter.
Now the range of that cycle is expanding as more carbon dioxide is emitted from burning fossil fuels and other human activities, according to a study led by scientists at the Scripps Institution of Oceanography (SIO).
The findings come from a multi-year airborne survey of atmospheric chemistry called HIAPER Pole-to-Pole Observations, or HIPPO.
Results of the study are reported in a paper published online this week by the journal Science.
The National Science Foundation (NSF), along with the U.S. Department of Energy, the National Center for Atmospheric Research (NCAR), the National Oceanic and Atmospheric Administration (NOAA) and the Office of Naval Research funded the study.
“This research provides dramatic evidence of the significant influence the land-based biosphere can have on the amplitude [amount of change] in seasonal trends of carbon dioxide exchange,” says Sylvia Edgerton, program director in NSF’s Division of Atmospheric and Geospace Sciences, which funded the research.
Observations of atmospheric carbon dioxide made by aircraft at altitudes between 3 and 6 kilometers (10,000-20,000 feet) show that seasonal carbon dioxide variations have substantially changed during the last 50 years.
The amplitude increased by roughly 50 percent across high latitude regions north of 45° N, compared with previous aircraft observations from the late 1950s and early 1960s.
This means that more carbon is accumulating in forests and other vegetation and soils in the Northern Hemisphere during the summer, and more carbon is being released in the fall and winter, says study lead scientist Heather Graven of SIO.
It’s not yet understood, she says, why the increase in seasonal amplitude of carbon dioxide concentration is so large, but it’s a clear signal of widespread changes in northern ecosystems.
“The atmospheric carbon dioxide observations are important because they show the combined effect of ecological changes over large regions,” says Graven.
“This reinforces ground-based studies that show that substantial changes are occurring as a result of rising carbon dioxide concentrations, warming temperatures and changing land management, including the expansion of forests in some regions and the poleward migration of ecosystems.”
Adds Peter Milne, a program director in NSF’s Division of Atmospheric and Geospace Sciences, “We can easily measure the greenhouse gas budget from a single smokestack, but somewhat less well for a stand of trees. Knowing that for the entire planet is much more challenging.
“Taking advantage of the long-duration and high-altitude-profiling capabilities of the NSF Gulfstream V aircraft [also known as HIAPER], the HIPPO project was designed to take a ‘snapshot’ of the global troposphere [Earth’s lowest atmospheric layer] to see whether we can explain and model greenhouse gas distribution.”
In the study, the scientists compared the recent aircraft data with aircraft data gathered from 1958 to 1961 using U.S. Air Force weather reconnaissance flights.
The older data were analyzed by SIO geochemist Charles David Keeling, the father of Ralph Keeling, also an SIO scientist and a member of the research team.
These aircraft measurements were done at the time Charles Keeling was beginning continuous carbon dioxide measurements at Mauna Loa, Hawaii.
While the Mauna Loa measurements are now widely recognized as the “Keeling Curve,” the early aircraft data were all-but-forgotten.
Carbon dioxide concentrations in the atmosphere have varied between 170 and 280 parts per million during the last 800,000 years.
When Charles Keeling began collecting data at Mauna Loa in 1958, the concentration had risen to about 315 parts per million.
In May, 2013, daily carbon dioxide measurements at Mauna Loa exceeded 400 parts per million–for the first time in human history.
Recent observations aboard the Gulfstream V were made during regular flights conducted during the HIPPO campaign, from 2009 to 2011.
The aircraft repeatedly ascended and descended from a few hundred meters to roughly 12 kilometers (40,000 feet) in the skies between the North Pole and Antarctica. The goal was constructing a unique snapshot of the chemical composition of the atmosphere.
Additional recent data comes from regular flights conducted by NOAA at a network of locations.
Increasing carbon dioxide amplitude since 1960 had already been observed at two ground-based stations: Mauna Loa and Barrow, Alaska.
Other stations operated by Scripps and NOAA only began measuring carbon dioxide in the 1970s to 1990s.
The aircraft-based observations uniquely show the large area in northern high latitudes where carbon dioxide amplitude increased strongly since 1960.
The exact reasons for the wider seasonal swings in carbon dioxide concentration remain to be determined, say the researchers.
Although plant activity can increase with warmer temperatures and higher carbon dioxideconcentrations, the change in carbon dioxide amplitude over the last 50 years is larger than expected from these effects.
Carbon dioxide concentration has increased by 23 percent, and average temperature north of 30°N has increased by one degree C, since 1960.
Other factors may be changes in the amount of carbon in leaves, wood or roots; changes in the extent or species composition of ecosystems; or changes in the timing of plant photosynthesis and respiration.
Simulating complex processes in land-based ecosystems with models is a challenge, scientists have found.
The observed change in carbon dioxide amplitude is larger than that simulated by models used by the Intergovernmental Panel on Climate Change (IPCC).
While this underestimate does not call into question the response of climate to carbon dioxide concentration in the IPCC models, the researchers say, it does suggest that a better understanding of what happened during the last 50 years could improve projections of future ecosystem changes.
The bottom line, according to Graven, Ralph Keeling and colleagues, is that Northern ecosystems appear to be behaving differently than they did 50 years ago.
In addition to Graven and Ralph Keeling, Science paper co-authors include Stephen Piper, Lisa Welp and Jonathan Bent of SIO; Prabir Patra of the Research Institute for Global Change in Yokohama, Japan; Britton Stephens of NCAR; Steven Wofsy, Bruce Daube and Gregory Santoni of Harvard University; Colm Sweeney of NOAA and the Cooperative Institute for Research in Environmental Sciences at the University of Colorado, Boulder; Pieter Tans of NOAA; John Kelley of the University of Alaska, Fairbanks and Eric Kort of the Jet Propulsion Laboratory in Pasadena, Calif.
-NSF-
Related Websites
NSF News: First Global Picture of Greenhouse Gases Emerges from Pole-to-Pole Research Flights: http://nsf.gov/news/news_summ.jsp?cntn_id=121566
HIAPER Pole-to-Pole Observations (HIPPO) Study: http://hippo.ucar.edu/
NSF Award: Collaborative Research: HIAPER Pole-to-Pole Observations (HIPPO) of Carbon Cycle and Greenhouse Gases: http://www.nsf.gov/awardsearch/showAward?AWD_ID=0628575
A 1 year graph-I’m overwhelmed.
Too much data to absorb in one sitting-don’t ‘cha think?
Hmmm, so the earth has been greening because of CO2. Wouldn’t it stand to reason that if there is more vegetation, that more CO2 would be absorbed by the extra vegetation during the spring and summer months? Or is this too rocket-sciency?
Maybe it’s as simple as farmers raising more crops, and doing better at making fertilizer in the winter.
“Northern ecosystems appear to be behaving differently than they did 50 years ago.”
What about 500, 5,000, 50,000, 500,000, and 5,000,000 years ago? 50 years is nothing in the grand scheme of things. For everything there is a season, perhaps we’re just in a season for this. why jump to the conclusion that it’s CAGW?.
And how much of the total atmospheric CO2 can be directly attributed to humanity?
Let’s talk about sensitivity instead.
Finally, an anthropogenic signal understandable and believable by all. The warmists are happy in the spring, when they aren’t paying attention to the weather and everyone is enjoying the outdoors. Then, the warmists get too hot in the summer and start paying attention to tornadoes, record high temperatures and annual thinning of the arctic ice. Then, the weather starts producing hurricanes and the warmists start hyperventilating, increasing the CO2 output. Finally, in the winter the warmists are all locked inside with each other and start slinging back beer, which really ups the ante in CO2 and methane production. Then spring comes again and the cycle repeats.
“This means that more carbon is accumulating in forests and other vegetation and soils in the Northern Hemisphere during the summer, and more carbon is being released in the fall and winter, says study lead scientist Heather Graven of SIO. It’s not yet understood, she says, why the increase in seasonal amplitude of carbon dioxide concentration is so large, but it’s a clear signal of widespread changes in northern ecosystems”
I wonder how this squares with David Coe’s Figure 1.2 here:
http://www.bishop-hill.net/storage/Atmospheric%20Carbon%20Dioxide%20Control%20Mechanisms-Part%201.pdf
… seemingly NOT produced by decaying vegetation in the frozen northern winter. Hmm…
Stupid question of the day (or is it?).
Where else in the world are carbon dioxide levels measured and how many parts per million are the readings for that, or those, monitoring stations?
” Seasonal carbon dioxide range expanding as more is added to Earth’s atmosphere ”
And that’s a bad thing?
.
In short, photosyntesis depending species grow better at higher carbondioxide levels.
It would have been easier to ask a tomato farmer who uses greenhouses …
This is hardly a new concept.
The Idso’s have been all over this for more than 20 years.
http://www.co2science.org/subject/other/co2amp.php
-Chip
I would investigate wildfires as a function of changes to land use management practices.
I’m not sure that they are accounting for the changes in atmospheric circulation; but 50 years doesn’t even cover one warm/cooling cycle.
I’ve raised the possibility that the ozone hole may vary with magnetic field strength because O2 is strongly paramagnetic (attracted to the poles of a magnet – ie the polar regions of the earth) while all other atmospheric gases including O3 are diamagnetic and are therefore repelled from magnetic poles. The NASA imagery does indeed show that the O3 isn’t in fact depleted but is rather “rolled back” like a turtle-neck sweater’s collar – supporting my hypothesis.
http://ozonewatch.gsfc.nasa.gov/Scripts/big_image.php?date=2013-08-09&hem=S&source=IOMI_PAURA_V8F_MGEOS5FP§ion=HOME
Moreover in a recent post on the ozone hole here at WUWT, I predicted there would also be a “hole” of all the other gases in the atmosphere except O2 which would push its way in to the polar region, both displacing the other gases and assisted by the diamagnetics of the others that would force them toward the equator. One commenter reported there was another paper that reported on the coincident N2 hole in the polar regions.
I also searched out a NASA image of global CO2 and lo and behold, it also displays the same concentrated collars and a CO2 “hole” at the poles although there is some weird radial zoning of CO2 at the south pole along with deeply depleted zones (instrument?).
http://www.jpl.nasa.gov/news/news.php?release=2008-189
It would be interesting to see what the other gas Scripps analysis patterns were along their pole to pole traverses. Presumably it supports the Nasa imagery. Also this effect could, in part, compromise the Mauna Loa CO2 representativeness globally (see Hawaii on the CO2 distributioin link. Indeed, if carbon dioxide emissions actually doubled, ML may record a tripling globally because of the polar roll back effect. Or the “Pearse Effect” has a nice ring! There is no way that CFCs caused all the atmospheric gases other than O2 to exit the poles. Occam would suggest the magnetic effects are the common cause. Also, the magnetic effects are increased in cold temperatures. I thought I’d better say all this before Scripps “corrects” its data.
So much for the claim that CO2 is going to ‘accumulate in the atmosphere for centuries’ – the biosphere will just increase in the presence of CO2 and the rate of conversion to plant material will increase. Why are mathematicians so fond of inventing constants?
I suggest they see how well their results correlate with seasonal Arctic sea ice cover.
Robert Wykoff – You wonder whether the extra vegetation is the reason why “the increase in seasonal amplitude of carbon dioxide concentration is so large”. It was my first thought too, but the increase in vegetation is reported as being only about 6% over 2 decades (http://www.impactlab.net/2008/06/09/scientists-surprised-to-find-earths-biosphere-booming/), probably not enough to explain the reported amplitude increase of 50% over 50 years. Anonymoose mentions increased agriculture, but that would presumably be included in the “6%”. It would appear that plants become healthier and more vigorous with increased CO2, as reported in the link supplied by Chip Knappenberger (http://www.co2science.org/subject/other/co2amp.php).
Paul – try http://scrippsco2.ucsd.edu/data/atmospheric_co2.html for CO2 measuring stations and their data.
Gary Pearse on August 12, 2013 at 2:05 pm
But Mauna Loa emits carbon dioxide, like any vulcano (active, dormant and “dead”)!
Doesn’t it affect the measurements …?
Does this also mean summer levels of oxygen are higher due to the increased photosynthesis?
Science WIN: Measuring CO2 levels with that degree of accuracy
Science FAIL: Assuming all variations are from human causes
Science WIN: Observing massive reduction in CO2 levels during NH growing season
Science FAIL: Assuming all variations are from human causes
Science WIN: Description of resources used to get detailed measurements
Science FAIL: liberally peppering the description with assertions that the variations are from human causes
Has anyone compared (global) deforestation with carbon dioxide levels? Some countries have basically no forest left, like Easter Island. Indonesia isn’t far from …
Ian W – Net biosphere takeup is just not enough to make a decent dent. “3.4 petagrams of carbon over 18 years” (see impactlab link in my prev comment) is about 16 mmt per month, vs some 2,600 mmt per month from fossil fuels.
SasjaL – deforestation is outweighed by growth elsewhere, see impactlab link in earlier comment.
This is becoming typical of climate science. Take two readings, draw a line and conclude it represents a “trend”.
Same thing happened with the gulf stream “stopping”. One measurement was taken, then ten years or so later another estimation was lower. OMG, the gulf stream is stopping. Only, the third time it was measured it was back up and we realise that it is not some imuable constant of climate the has gone haywire but a parameter that varies.
Then there was the ozone “hole”… which closed up again.
Now if we look at rate of change of CO2 ( or the rate of rate of change in this graph ) we see that the amplitude varies up and down over time in what looks to be due to interference patterns between different oscillations:
http://climategrog.wordpress.com/?attachment_id=225
Two punctual measurements set 50 years apart really don’t tell you anything apart from the fact the two are different.
But when such respected scientists report : “The bottom line, according to Graven, Ralph Keeling and colleagues, is that Northern ecosystems appear to be behaving differently than they did 50 years ago.” , it is made to sound like OMG even the annual carbon cycle is getting “weird” now.
In fact it says nothing about patterns 50 years ago and whether those patterns are the same or different now. This is really a non result. There is insufficient data so say anything other than the annual variation is variable.
My suspicion is that what happens in the oceans (most of the planet) is a lot more important than what the forests are doing. It isn’t only the land that greens with higher CO2.
Equally the annual temperature cycle is similarly variable
http://climategrog.wordpress.com/?attachment_id=223
and since d/dt(CO2) is strongly correlated to temperature that could be a wee clue as to why the CO2 amplitude varies.
I don’t know if anyone fully appreciates what nature can do with a little additional atmospheric carbon dioxide. I was surprised – and surprised I was surprised once I considered the situation -when I learned the following tidbit: in the UK (specified only because that was the locale of the research) on a nice, warm sunny day, wheat crops stop growing in the afternoon. Wheat, a C3 crop, needs minimum atmospheric carbon dioxide to photosynthesize, but with levels far exceeding that, there is no problem,right? No, wrong. Imagine hundreds of acres of growing plants, all scrubbing the air of that gas. In that LOCAL environment, CO2 becomes too depleted by late afternoon for plant growth to take place. Now imagine that happening in C3 plants throughout the world, in ADDITION to plants growing in environments in which they would not otherwise grow. Clearly, it seems we have underestimated how CO2 ‘thirsty’ the plant world is.
why do these morons keep insisting that 250-280 ppm is “normal”?
Less “amplitude” is exactly what you would expect when something is limiting….
…and more “amplitude” is exactly what you would expect as it becomes less limiting
Sounds like the number of plants is increasing.
Pretty much what should be expected from increasing CO2 in the atmoshpere.
“Now the range of that cycle is expanding as more carbon dioxide is emitted from burning fossil fuels and other human activities,…”
What rubbish. The increase from human CO2 is almost zilch compared to that from the ocean and bio output. Those two are supplying ~97% of the increase. The cycle is getting larger because there is more, predominately NH, plant life sucking down on it every summer.
Plant life is a negative feedback to CO2 and global warming. (And eco-whackjobs want to cut down US forests to power electric power plants in England…)
As the human population expands, change in land usage has to be a significant factor. I found the following research most informative and have used it as a basis for my understanding of how CO2 rather than being evenly distributed, varies considerably over annual cycles and geography as must its effect.
“Mechanisms for synoptic variations of atmospheric CO2 in North America, South America and Europehttp”
http://www.atmos-chem-phys.net/8/7239/2008/acp-8-7239-2008.pdf
Maybe it’s just the ocean’s ability to absorb and release CO2 relative to temperature?
To Jtom. That seems to be a significant point! Are plants really that CO2 thirsty? What level CO2 would give them what they need? What would happen if they got to that level in terms of growth and expansion of the biosphere and the oceans.
Repeat after me: Co2 is a toxin.
Here are the results:
When the oceans of the world get cooler, more CO2 will be absorbed. What would the CAGW think if that became the case? They would say: “See, see – less CO2 and it is cooler!”
Here is the link to the abstract: http://www.sciencemag.org/content/early/2013/08/07/science.1239207
The original is still behind the paywall.
The inference that the change is due mainly to northern boreal forests comes from the geographical distribution of the change: 50% for latitudes 45 to 90 north; less than 25% of latitudes 10 to 45 north.
The text of the article has hedges: seems, may be, evidently. All of the estimates have estimates of uncertaintly.
Here is a quote: None of the CMIP5 models can account for the increase in CO2 amplitude north of 45°N at 500 mb between 1958-61 and 2009-11 (Fig. 4). Moreover, the recent CO2 amplitude varies strongly between models, with a range of 6 to 19 ppm compared to the observed value of 13.8 ± 0.7 ppm. Previous studies have similarly shown that most terrestrial ecosystem models underestimate the long-term trend in CO2 amplitude at Mauna Loa (34), and include large errors in the seasonal amplitude of NEP at eddy flux sites (35).
Data are available through urls included in table s7 of the supplemental material. It does not seem that they have posted computer code yet.
Large seasonal changes illustrate how quickly carbon enters and exits the atmosphere. Some have said C02 last a very long time in the atmosphere and if that was true then we would not see these large seasonal changes. Smoothing hides data. I bet there is a swing between day and night tool Is there an hourly graph somewhere?
Thank God the plants now have more CO₂ to breathe in.
My broccoli were panting!
Peter Milne [in the post]: “We can easily measure the greenhouse gas budget from a single smokestack … ”
Well – yes – since most of these would have a CO2 gizmo in them these days ?
” … but somewhat less well for a stand of trees.”
Huh?
Ok. Bit more difficult, but some agencies have started to do this. I have even considered setting something up for one of my stands of trees – with no expectation of getting a grant for it.
The tricky bit for me would be the airflow direction rather than the CO2 monitoring.
Paul at 1:47 –
“Where else in the world are carbon dioxide levels measured and how many parts per million are the readings for that, or those, monitoring stations?”
Short answer – your local tavern, anywhere there is a cold store, grain silo, “intelligent” AC system? Ok just kidding, that’s internal monitoring.
It’s not a stupid question. I would like to know the answer as well. Seriously. Millions of premises have CO2 monitoring, so why not outdoor spaces?
Am I the only person monitoring airflow off the SPO? My little rig can even give a warning of an upwind bushfire.
Argo buoys aren’t that cheap but several thousand have been chucked in the ocean.
SasjaL says:
August 12, 2013 at 2:36 pm
Gary Pearse on August 12, 2013 at 2:05 pm
“But Mauna Loa emits carbon dioxide, like any vulcano (active, dormant and “dead”)!
Doesn’t it affect the measurements ”
I asked this question myself some time ago but everyone seems happy that the measurements are okay. I think a look at the CO2 global distribution says even if they are “okay” they sure aren’t measuring global CO2 levels:
http://www.jpl.nasa.gov/news/news.php?release=2008-189
Surely there is a lot more to this seasonal fluctuation.
A quick look at the Scripps site for CO2 data shows the seasonal variation on southern hemisphere measuring sites to be only 1 or 2 ppm annual variation.
In more detail the March to May part of the graph above shows short term “cycles”.
There may be up to 4 cycles in a month which is about the frequency of weather systems moving through.
Is this the ocean breathing in and out as these high and low pressure systems go past?
Is the equilibrium then a direct relation to the ocean CO2 content and the changes in seasonal ocean temperature?
The way I understood Murry Salby’s presentations this is as he described.
A 2.5C water temp rise in summer could give 6ppm increase in CO2 from a base of 300ppm, and would then give a 9ppm change when the atmosphere /ocean system is at 400ppm (atmospheric),and the ocean 0.5C warmer than 50 years ago..
During that 50 year period, US/National trend line yields for corn have tripled. From around 50 bushels/acre to 150 bushels/acre.
http://www.agry.purdue.edu/ext/corn/news/timeless/YieldTrends.html
http://notrickszone.com/2012/12/29/higher-co2-concentrations-will-feed-a-billion-more-people/
Agriculture has expanded and crop yields exploded upwards with great assistance from that entirely beneficial gas, CO2. Those huge crops use more and more CO2 and the increasing CO2 is producing even bigger crops.
This is helping us to to provide food for a world population that has basically doubled during that same time frame.
http://www.google.com/imgres?imgurl=http://www.census.gov/population/international/data/idb/images/worldpop.png&imgrefurl=http://www.census.gov/population/international/data/idb/worldpopgraph.php&h=753&w=978&sz=58&tbnid=iLBnEugqzDPKuM:&tbnh=90&tbnw=117&zoom=1&usg=__u6_fmQldnR5wCBWaATtp2AmBmsw=&docid=G_LEIPJ61jT6nM&hl=en&sa=X&ei=NXoJUuXHDomayQHNkYDwDg&ved=0CD4Q9QEwAg&dur=805
Cutting back on CO2 emissions or if we see global cooling (of oceans) that causes them to absorb more CO2 at the same time that agriculture suffers from the irrefutable negative consequences when our planet cools, could make it very challenging to continue to produce enough food for the growing world population.
The day-to-day variation in the data points is very interesting. Sometimes rising continuously by minute amounts, sometimes falling continuously by minute amounts. Other times random distribution within the range. Why do you think that is?
Cynical Scientst says: “My suspicion is that what happens in the oceans (most of the planet) is a lot more important than what the forests are doing. It isn’t only the land that greens with higher CO2.” See also comments by JimS and Beesaman and Greg Goodman, above.
More shrubbery grows in the NH in Spring just before the CO2 drops. Therefore, the former causes the latter. Must be. Post hoc is one of the fumblemental principles of alarmist science, right below ad hominem. (/s) Of course, when it’s summer in the NH, it’s winter in the SH and the oceans there are cooling. Colder seawater (and rain) will absorb more CO2, so CO2 should drop as a result.
The NSF article pretends absolutely nothing is happening below the equator. Hint: record ice extent in Antarctica.
Mike Jonas on August 12, 2013 at 2:48 pm
Have doubts though. Close to the equator, where trees grows fast, it is possible to compensate within reasonable time. Here in Sweden, it takes 40-50 years to replace high quality pine …
It is more lucrative to cut down the trees and not planting anything new (despite prohibition, no legal sanction …) here. Same thing is also happening in Brazil, as shown on Swedish television (BBC produced program).
Doesn’t methane decompose to CO2 too?
According to World Bank’s Cereal Yields/hectare data, crop yields in the US have increased from 3,772kg/hectare in 1980 to 6,818kg/hectare in 2011, which is an 80% increase.
http://data.worldbank.org/indicator/AG.YLD.CREL.KG
Obviously a lot of the crop-yield increase can be attributed to improved irrigation, increased fertilizer usage, improved hybrid seeds, etc., but obviously increased CO2 fertilization from higher atmospheric CO2 concentrations has played a huge role in the phenomenal increase in crop yields over the last couple of decades.
I’d also like to see studies done on phytoplankton concentrations over the past 25 years, as I’m sure plankton levels have also increased substantially due to increased CO2 levels, which has improved the ocean’s ecosystem.
The warmunistas’ almost pathological aversion to attributing any kind of net benefit to increased CO2 levels is hurting the advancement of science. I’ll be happy to see the day when sanity is restored to climatology and other branches of science that have been infected with the CAGW virus..
Carbon dioxide concentrations in the atmosphere have varied between 170 and 280 parts per million during the last 800,000 years.
Really? It seems CO2 neared 290 ppm around 128,000 years and 400,000 years ago, and was above 290 ppm over 332,000 years ago
http://www.geocraft.com/WVFossils/panorama/panorama11.html
Even then, what’s less than a million years in light of the hundreds of millions of years when CO2 levels were much higher than at modern times?
http://en.wikipedia.org/wiki/File:Phanerozoic_Carbon_Dioxide.png
CO2 is the currency of life in the biosphere economy. The more CO2 the more velocity in the economy. (Humans are 19% carbon.)
Sugar is the basic unit in botany, C6H12O6. Saccharides. Cellulose is polysaccharide, a chain of sugars linked together. 6 carbon atoms per saccharide. Each saccharide synthesis consumes 6 CO2 molecules. By weight that is 3 grams of CO2 per 2 grams of Sugar. 3:2 ratio.
1 gram of sugar equals 1.5 grams of CO2.
This ain’t rocket science, or climate science, this is biology. The biosphere is opportunistic. More CO2 equals more life, from primary producers on through the web to decomposers. This is surprising?
It’s not yet understood, she says, why the increase in seasonal amplitude of carbon dioxide concentration is so large, but it’s a clear signal of widespread changes in northern ecosystems.
It’s pretty obvious. CO2 is the main limiting factor in tree growth. A study a couple of years back, convinced me that something we were all taught in school was wrong. Trees don’t grow taller to access more sunlight. Trees grow taller to access more CO2.
I found the results in this paper much larger than what the Mauna Loa data show. I get a 6.7% increase in CO2 ‘breathing’ from plants when comparing today’s measurements with those 50 years ago.
http://cosmoscon.com/2013/08/12/swinging-co2-levels/
Mauna Loa is probably the worst place on Earth to measure land biosphere effects on CO2 as it is in the middle of the largest ocean. And Barrow, Alaska isn’t much better.
And in the great evolutionary contest between grasses and trees. Trees are winning because of increased CO2.
http://rstb.royalsocietypublishing.org/content/367/1588/601.long
Oh for heaven’s sake. Do these people not have any information at all about farming practices over the same time span? Really? I’ll bet they think crop circles are related to those silly man-made round shapes. I’ll see if I can dig up a photo of central Oregon taken in the 50’s compared to now.
Robert Wykoff says:
August 12, 2013 at 1:20 pm
Hmmm, so the earth has been greening because of CO2. Wouldn’t it stand to reason that if there is more vegetation, that more CO2 would be absorbed by the extra vegetation during the spring and summer months? Or is this too rocket-sciency?
My exact thoughts as well. In addition, almost all plant life above 45° either dies or goes dormant in the winter. As such, any increases in growth due to CO2 will have a larger impact on the swings. The tropics and sub-tropics are green all year long and would have little impact on the CO2 levels. No rocket science required. 😉
An increased range (amplitude) of atmospheric CO2 means that there is more photosynthetic activity going on: the increase is directly proportional to seasonal growth. The effect will be greater in the higher altitudes and latitudes than in the lower ones, though anyone who has been in tropical or subtropical areas is well aware that there are significant “summer” growing periods in those areas, too.
Another positive thing in the biosphere that is now perceived as a negative.
One thing I’ve noticed: all horror stories about the death of the “biosphere” are actually stories about the loss of (essentially) megafauna. The type the indigenous peoples hunted to extinction in centuries past. Flora, green plants, not just human-agricultural, have increased to the point that satellites can notice it. The oceans MUST have more phytoplancton because the predators, i.e. the fish, whales etc. that Greenpeace et al moan about, are less. Whatever does not get eaten lives to reproduce more. There has got to be a large amount of krill relative to the pre-whaling days. Bugs: less birds, more bugs.
The biosphere is changing, not shrinking. Diversity is falling, or at least the numbers within diverse species are falling so that on a time per capture basis it looks as though diversity is falling. (And certainly extinctions are occurring through over harvesting and loss of habitat.) But the total biological output of the Earth shrinking? I doubt it. I doubt that there are large ecological niches that are devoid of life. Darwin probably would agree with me here.
The British countryside is a human-engineered environment, a Victorian garden of sorts. But it is not dead. The death of the world is no more real or a danger than that of the British countryside from what was there in the Medieval days. It is just different. Lacks bears and lions, yes. But I’m not sure the Sierra Club would want their members to be eaten by what is now missing, though if the President of the Sierra Club and David Suzuki were removed from the ecosystem by a reintroduced, GMO Dire wolf, there would be a particularly large amount of irony in the loss of that part of the biosphere.
I note with interest that no one including the authors have mentioned the cryosphere as the main cause of a rise and fall in CO2. Plants and dead vegetation do not emit masses of CO2 as claimed. Water does, when frozen.
It is obvious that most of the annual variation in snow and ice cover is over the NH land area. Snow and ice don’t have any CO2 to speak of while fresh water and seawater have lots. The variation in snow cover in the SH is small and the CO2 change consequently minor from season to season.
The increase in the variation may be mostly from an increase in the total mass of water melting and freezing seasonally. There was a small increase in average temperature but a relatively larger increase in the total mass of H2O changing phase. Whatever the mass of this seasonal melt is, the mass of CO2 cycling in and out is 0.113% of that total. No other mooted contribution comes close to this huge exchange.
The unfortunate (for CAGW) consequence of this chemical reality is that melting glaciers and ice caps absorb huge amounts of CO2, if they don’t refreeze. Rather puts the cat of consequences among the pigeons of blithe assumptions. The cycling is caused by water and ice, not biomass. When the snowpack and ice stop retreating each year the decrease stops. The increase begins with the first snows.
Gary Pearse on August 12, 2013 at 5:13 pm
During my time at Swedish post mandatory school (technical, ~highschool) in the early 1980’s, it would have been classified as contaminated measurements. Without any certen clue how much the vulcano interfere with the measurement, it is of low if any value. They have to know the activity level of the vulcano and even the vulcano scientists have issues with that matter. With the knowledge available today, no one is able to predict an outbreak long enough before it takes place and not that much about what’s happening in between outbreaks. The measurements gives the vulcano scientists the history but not the future. (Maybe they should use the IPCC models? [/sarc]) At school, trying to perform such an act in lab reports, without any decent explaining about pro’s and con’s regarding the measurements incl. used methods and if any compensation without any reasonable cause, it was a obvious fail! We only got one chance to correct a faulty lab report …
Consider that Manua Loa is the world’s largest active volcano! It’s like shouting in an echo chamber, you’ll get what you “ask” for …
Regarding the NASA article,
Moustafa Chahine is mentioning something that is very important and is valid for temperature as well: “Carbon dioxide is difficult to measure and track,“. Why? Simple, it changes constantly with time and place.
The NASA map of concern shows that the carbon dioxide varies with location, but not over time. Closer to the polar regions, it differs between summer and winter. Even though the period of measurement was between Sept.’02 and July ’08, the map only represent one month: July ’08! Why this specific month? The variations are not showed in the map of concern (max/min).
Anyway and far from irrelevant, a period of almost six years is “a drop in the ocean“, compared to 3.5-4 billion years (the age of the climate), it’s still statistics that we are dealing with …
Crispin in Waterloo on August 12, 2013 at 8:15 pm
Interesting, but also the temperature of the water is important for how much carbon dioxide it can absorb.
This means that more carbon is accumulating in forests and other vegetation and soils in the Northern Hemisphere during the summer, and more carbon is being released in the fall and winter, says study lead scientist Heather Graven of SIO.
So when the the earth is frozen and covered in snow and ice, more CO2 is released…right.
Jbutzi: sorry, but I have no answers for your questions. I suppose we could find some research indicating the optimal level of CO2 for C3 crops, but I suspect knowing what the levels need to start at to ensure meeting a minimum level in a local environment throughout a growing day would require extensive field research. I’m afraid other variables, such as the number of acres planted and wind would play significant roles.
I think we all need to be cognizant of the fact that photosynthetic organisms evolved in an atmosphere very different from today’s. For most of the last three billion years, atmospheric carbon dioxide levels were up to 20%, and were still at 5% when dinosaurs roamed. Personally, I think life as we know it was facing extinction with carbon dioxide dropping as low as it did, and only the evolution of wood-digesting organisms like termites prevented it. Life could not have continued if much more carbon dioxide had been sequestered beneath the earth. Afterall, what was the primary reason the levels dropped from 20% to .03%?
Jbutzi: It appears that optimal CO2 levels for C3 crops is 1000 – 1200 ppm. I would guess (purely a guess) that you would need to start the day with closer to 1500 ppm to maintain a minimum of 1200 ppm throughout the day for a good size crop. We still have a long way to go. I like to entertain the idea that such levels on a global basis could have some interesting surprises for us with respect to changes in the plant kingdom. At the very least, green thumbs and home gardens would flourish, and lawn mower sales would be brisk!
Yes, it’s breathing.
http://www.thisiscolossal.com/2013/08/breathing-earth/
And I agree that the seasonal CO2 cycle is caused by water and ice, not biosphere. Furthermore, the cycle itself causes the accumulation of CO2 in the atmosphere, which is temperature dependent. At sufficiently low temperature it’s zero and lower than that it’s negative.
Which sort of rules out the assumption that it is entirley down to man.
Sure, agriculture is important but so is river managemnt. Al that silt that used ot be picke dup in floods no longer feeds the Oceans. But all that fertiliser does. It’s not just down to the land.
Also, this strongly challenges the assumption that the releases from reservoirs of CO2 in the Ocean’s are dwarfed by man’s actions.
Which explains why CO2 follows temperature in the ice-core records. And that is a tad awkward for the AGW theory as the MWP did happen.
It’s plant life getting livelier as it gets more of what it needs. Can I have more, please, Sir?
I live in Australia and my grass is seriously growing at this time of year (late winter – early spring) I know there is more land mass in the Northern Hemisphere, but is it really that marked – especially when one considers that the oceans (of which there is more in the Southern Hemisphere) are not entirely devoid of plant matter. ????
Not new science. The Mauna Loa data is more consistant with oceanic CO2 use than that of continental.
Crispin in Waterloo says:
August 12, 2013 at 8:15 pm
I note with interest that no one including the authors have mentioned the cryosphere as the main cause of a rise and fall in CO2. Plants and dead vegetation do not emit masses of CO2 as claimed. Water does, when frozen.
The 13C/12C ratio and the oxygen level goes opposite to the CO2 level over the seasons. That means that both plant growth and decay are the main cause of the CO2 changes as well as in spring/summer as in fall/winter, especially in the NH. Less in the SH, as there is more ocean surface.
If the ocean freezing was the main cause, then the seasonal variation of CO2 would be much larger in the SH and somewhat less in the NH. But we see the opposite.
See fig. 5 in
http://www.bowdoin.edu/~mbattle/papers_posters_and_talks/BenderGBC2005.pdf
That also shows that the seasonal O2 variation at Barrow increased over time, which is a consequence of more vegetation growth and decay in the northern latitudes. Probably a matter of both more growing area and faster growing crops due to slightly higher temperatures and longer growth seasons.
Further, vegetation decay doesn’t stop in winter: bacteria can go on, as long as not everything is frozen. The decay is exothermic, at least in the first months and may prevent freezing in the deeper organic layers under snow cover. In the mid-latitudes with less freezing days, the decay goes on all year.
JimS says:
August 12, 2013 at 4:15 pm
///////////////////////////
YES.
But the argument would not be compelling if manmade CO2 emissions continue to rise unabated, since it would suggest that CO2 levels are driven by natural factors, rather than simply by man’s activities.
jorgekafkazar (August 12, 2013 at 5:52 pm) “The NSF article pretends absolutely nothing is happening below the equator. Hint: record ice extent in Antarctica.”
I might need more hints. I don’t think the observed trough in atmospheric CO2 in July has anything to do with ice at either pole. Perhaps you are implying the cold temperatures in the SH in July before peak ice in the Antarctic would absorb more CO2? On the other thread George E Smith had the same theory except at the north pole instead of the south.
If ocean temperature were a better explanation of the annual wiggle than the biosphere, I would certainly be interested in that theory. But AFAICS, it is not.
Ferdinand Engelbeen says:
August 13, 2013 at 2:08 am
“Further, vegetation decay doesn’t stop in winter: bacteria can go on, as long as not everything is frozen. The decay is exothermic, at least in the first months and may prevent freezing in the deeper organic layers under snow cover. In the mid-latitudes with less freezing days, the decay goes on all year.”
Vegetal decay may not stop entirely in northern latitudes in fall and winter, but my experience of over six decades of life in southern Minnesota suggests it doesn’t really do much until the next growing season commences and that most plant material breakdown occurs in conjunction with new growth, not in opposition to it. A springtime walk through the woods around here will display plant litter from the previous Fall which is a sodden mess, but whose actual mass has declined hardly at all from when it hit the ground, certainly not at a level that would create the nearly symmetrical pattern of the Keeling graph.
I have no idea what is creating the lovely sawtooth pattern in this graph, but the notion that plants are releasing an equal quantity of CO2 to what they take up in Spring and Summer in Winter at latitudes north of 45 degrees has always struck me as completely boneheaded. If you choose to disagree I would suggest you peruse the CO2 records which are recorded at the South Pole. The pattern there is no where near as precise, but it is still completely discernible, with no vegatation within several thousand miles.
Forgot this
http://cdiac.ornl.gov/trends/co2/graphics/South_Pole_CO2.jpg
I like the way the NSF is trying to attribute their finding with statements like this “Northern Hemisphere land-based ecosystems “taking deeper breaths,” scientists find” to actual living and breathing entities.
Dave Wendt on August 13, 2013 at 3:52 am
“and that most plant material breakdown occurs in conjunction with new growth, ”
Indeed, as new(er) plants take advantage of old dead ones, used as building material and fertilizers. Like carbon dioxide – food, part of the eco cycle.
The carbon dioxide diet of plants:
http://www.co2science.org/data/plant_growth/photo/photo_subject.php
“Northern ecosystems appear to be behaving differently than they did 50 years ago.”
150 years ago humans used 4% of the land’s surface for agriculture and cities combined. Today we used 4% for cities alone and 40% for agriculture. Most of this change has taken place in the Northern hemisphere, because this is where the land is and this is where the wealth is.
The farmland from 150 years ago is now cities. Large portions of the grasslands, forests and even deserts from 150 years ago are now devoted to agriculture. And CO2 levels are now above the minimum required for C3 photosynthesis – something that was not true 150 years ago.
Of course there has been a change. The last 50 years have simply been a continuation of events that started 150 years ago as the world began to industrialize.
“The amplitude increased by roughly 50 percent across high latitude regions north of 45° N, compared with previous aircraft observations from the late 1950s and early 1960s”.
How much confidence do they have that the earlier observations (methods) are comparable to recent methods? If they are making some assumptions their conclusions may be bunk.
…. “more carbon is accumulating..during the summer, and more carbon is being released in the fall and winter, ”
Why is it that these scientists always seem to presume that there should NOT be this sort of variation over every time scale?
Isn’t it a wiser assumption that these many changes must occur as earth’s countless influences and responses are constantly varying individually?
How can nature possibly be stable? There is just too much going on.
“It’s not yet understood, she says, why the increase in seasonal amplitude of carbon dioxide concentration is so large, but it’s a clear signal of widespread changes in northern ecosystems”
“Northern ecosystems appear to be behaving differently than they did 50 years ago.”
IMO this kind of monitoring, comparing and speculation is useless and costly make work for the many professional ponderers. They’ve created careers out of what should be hobbies.
It’s all like monitoring sand dunes and trying to figure out why the shapes change.
I bet some years they change more than others. Isn’t that interesting?
Here in Oregon some of us are waiting and waiting (but not really) for the updated explanation for why there is nothing happening in the way of AGW Ocean Dead Zones. There never was.
Yet many millions are being devoured collecting water samples at various depths to monitor fluctuating oxygen levels because Jane Lubchenco, Jack Barth and Francis Chan cooked up an AGW connection to naturally occurring seasonal hypoxia and spread word of their fabrication around the globe. Their baseless pondering is everywhere. Google Oregon Ocean Dead Zones
and see the parasite of misinformation they infected the web with.
On previous post regarding the change in CO2 as measured at Mauna Loa, I have postulated that there appears to be both an annual cyclic CO2 change and a longer term change that warmists postulate can only be accounted for by the change in the evil burning of fossil fuels. I postulated an alternative theory, and have been busy trying to gather data to verify it. This ariticle seems to offer some proof or at least partially agree that my theory has merit.
.
My theory postulates that to accurately determine the CAUSE of the change in gaseous CO2 in the atmosphere, one must accurately measure both the “sources” and the “sinks” that govern the instantaneous CO2 concentration. It further postulates that the long term drift upwards in the CO2 concentration must be directly correlated to BOTH the ADDITIONS to CO2 from all sources AND the LOSSES caused by the loss of SINKS such as tropical forest vegetation. I believe but still need to prove that long term net loss of tropical forest vegetation and the long term net addition from all volcanic sources, are far more likely CAUSES for long term upward drift in CO2 than the small addition man has contributed by burning fossil fuels.
.
In this article the authors ponder the annual swing. They wonder why that swing has seen greater range in more recent years, and they ADMIT THAT THE ANNUAL CYCLIC SIGNAL IS CAUSED BY EXTRA PHOTOSYNTHETIC VEGETATION OUTSIDE OF THE TROPICS. Yet they fail to postulate that the long term upward drift is most likely associated with a change in vegetation that does NOT experience annual change, namely the long term loss of tropical forest vegetation! I wonder why not?
.
What say you all here at WUWT? Do you think this theory has merit? Do you know of any solid proof or data that disproves it?
jorgekafkazar: The NSF article pretends absolutely nothing is happening below the equator.
No. They merely did not perform any measurements there.
Steve Oregon: Why is it that these scientists always seem to presume that there should NOT be this sort of variation over every time scale?
Isn’t it a wiser assumption that these many changes must occur as earth’s countless influences and responses are constantly varying individually?
How can nature possibly be stable?
There is not presumption in the article at all about what happened in eras for which they have no measurements. All they have done, and it wasn’t easy, is document (at least partially) a particular change over a particular era and over a particular space a change in one measurable feature of the environment. Now that it has been done, it can be done more regularly and systematically over the next decades to see what happens. Differences, if any, between the Northern and Southern hemispheres should be informative.
ferd berple: Of course there has been a change.
And, …, now it has been measured.
Richard G: This ain’t rocket science, or climate science, this is biology. The biosphere is opportunistic. More CO2 equals more life, from primary producers on through the web to decomposers. This is surprising?
It’s still better to have actual measurements than not to have the measurements.
I think that for people who do not already know everything important this is an informative article. Are there any old reference data sets for the Southern Hemisphere so an experiment like this can be conducted there and possibly quantity the changes that have occurred there over the same time span?
The larger swings in seasonal CO2 uptake/release in the NH seems to be related to a longer growing season and especially a decrease in freezing days in the upper North. See:
http://cce.nasa.gov/meeting_2011/abs_and_discussions/mtg2011_ab_searchab_id17.html
and its link to the interesting poster.
http://cceo.gsfc.nasa.gov/mtg2011_ab_presentations/2011_Poster_Kim_220_17.pdf
based on satellite temperature and local CO2 flux measurements.
Matthew R Marler wrote,
“Now that it has been done, it can be done more regularly and systematically over the next decades to see what happens. Differences, if any, between the Northern and Southern hemispheres should be informative.”
You sure do apply a lot of unfounded confidence in what they have supposedly documented.
I don’t buy it at all. Either on what they think they have compared or the idea that their hypothesized fluctuation is meaningful.
Whatever methods and measurements they have and used from the 50s and 60s are not as reliable as today’s. So these folks most likely did make some presumptions.
Measuring for the sake of measuring has become an endless and limitless pursuit with imaginations and speculation always delivering the notion that all of it is meaningful.
With the world having so many known things (already measured) needing attention and resources it is a crying shame that so much is being allocated to this professional hobby work.
If I were in charge much of it would end today. But I am but a simple man.
It’s a good thing when plant asphyxiation lets up?
Steve Oregon: You sure do apply a lot of unfounded confidence in what they have supposedly documented.
Really? I look forward to studies in the future based on the same methodology. Confidence in some empirical results might then be justified. I used the word “informative”. A few people on this thread already know why the supposed result has happened. You confidently assert that knowledge about atmospheric CO2 is irrelevant. I agree that’s simple.
Dave Wendt says:
August 13, 2013 at 3:52 am
Vegetal decay may not stop entirely in northern latitudes in fall and winter, but my experience of over six decades of life in southern Minnesota suggests it doesn’t really do much until the next growing season commences and that most plant material breakdown occurs in conjunction with new growth, not in opposition to it.
That is largely true, but the most soluble compounds (sugars, proteins) are already gone in the first weeks. What rests is the cellulose frame and lignin which remain rather intact at low temperatures and the latter even need strong chemicals by specific fungi to break down, which mostly happens at higher temperatures.
From some more search it seems that most winter CO2 release is from soil bacteria under the snow layer, here from near the treeline in Alaska:
http://academic.research.microsoft.com/Publication/41858630/snow-distribution-soil-temperature-and-late-winter-co-2-efflux-from-soils-near-the-arctic-treeline:
Results showed that greater wintertime C loss from forests could offset greater summertime C gain.
DonV August 13, 2013 at 8:46 am “Yet they fail to postulate that the long term upward drift is most likely associated with a change in vegetation that does NOT experience annual change, namely the long term loss of tropical forest vegetation! I wonder why not?”
They already add land use changes: http://cdiac.ornl.gov/trends/landuse/houghton/houghton.html That would seem to cover long term tropical forest loss.
“””””……eric1skeptic says:
August 13, 2013 at 3:27 am
jorgekafkazar (August 12, 2013 at 5:52 pm) “The NSF article pretends absolutely nothing is happening below the equator. Hint: record ice extent in Antarctica.”
I might need more hints. I don’t think the observed trough in atmospheric CO2 in July has anything to do with ice at either pole. Perhaps you are implying the cold temperatures in the SH in July before peak ice in the Antarctic would absorb more CO2? On the other thread George E Smith had the same theory except at the north pole instead of the south.
If ocean temperature were a better explanation of the annual wiggle than the biosphere, I would certainly be interested in that theory. But AFAICS, it is not………..”””””””””””
Well at the south pole, there is neither a biological cycle, nor an open water refreeze cycle. Consequently, there is very little atmospheric CO2 cycle at the south pole. The NOAA data I have seen, says the south pole cyclic amplitude, is about -1 ppm. On the other hand, at the north pole, and throughout the entire high Arctic, the CO2 annual cycle is 18-20 ppm amplitude; and in that region you have both an open water refreeze cycle, of some 8-12 million squ km of ice, and an associated ocean biological cycle (the whales go there to feed on it).
The small out of phase signal at the south pole is a vestige of the “well mixed” atmospheric CO2 cycle occurring at the sea ice edge of Antarctica, which is about – 0.5 times the ML cycle amplitude..
Meanwhile, in the tropics, which is where ML is situated; you tend to not see a biological cycle such as might be seen in New England. Vegetation in the oceanic tropics, tends to grow continually; there isn’t much seasonality.
But compared to that, you assert: “””””….. I don’t think the observed trough in atmospheric CO2 in July has anything to do with ice at either pole…….”””””” and this: “””””…..But AFAICS, it is not…..”””””
I think, you might be on to something with your theories.
From the story:
The observed change in carbon dioxide amplitude is larger than that simulated by models used by the Intergovernmental Panel on Climate Change (IPCC).
Well, paint me surprised…. Model fail, again.
Chip Knappenberger says:
August 12, 2013 at 1:50 pm
This is hardly a new concept.
The Idso’s have been all over this for more than 20 years.
http://www.co2science.org/subject/other/co2amp.php
-Chip
Exactly, this is no new find, but a comfirmation of the fertilization effect. As explained there:
“As can be seen from these data, over the period 1958-1999 the “breath” of the biosphere has been considerably enhanced. The 19.5% increase in the strength of this phenomenon is primarily a direct result of atmospheric CO2 fertilization (Pearman and Hyson, 1981; Cleveland et al., 1983; Bacastow et al., 1985; Enting, 1987; Kohlmaier et al., 1989; Keeling et al., 1996), nitrogen-induced increases in the growth rates of earth’s ecosystems (Shindler and Bayley, 1993; Hudson et al., 1994; Galloway et al., 1995), and CO2-induced expansions in some of their ranges (Idso, 1995). A slight temperature increase reported in some Northern Hemisphere land areas over this time period may also be a contributing factor (Keeling et al., 1996; Myneni et al., 1997). Together, these phenomena combine to produce the results shown in the graph above, which stands as a strong testament to the reality of the ubiquitous “greening of the earth” (Idso, 1986) that is currently in progress.”
Thanks for posting the link from CO2 science, they have a very good database about plants fertilization effect through CO2:
http://www.co2science.org/data/plant_growth/plantgrowth.php
Jimbo says:
August 12, 2013 at 4:10 pm
Exactly, the greening has been obeserved by satellites too, so wonder who is wondering?
http://wattsupwiththat.com/2008/06/08/surprise-earths-biosphere-is-booming-co2-the-cause/
DonV says:
August 13, 2013 at 8:46 am
What say you all here at WUWT? Do you think this theory has merit? Do you know of any solid proof or data that disproves it?
Don, in the link I posted above you can read:
From the 2004 abstract: Our results indicate that global changes in climate have eased several critical climatic constraints to plant growth, such that net primary production increased 6% (3.4 petagrams of carbon over 18 years) globally. The largest increase was in tropical ecosystems. Amazon rain forests accounted for 42% of the global increase in net primary production, owing mainly to decreased cloud cover and the resulting increase in solar radiation.
So it looks like tropical rain forrest where not cut do indeed increase.I think this disproves your thesis, however I do not have data showing tropical forrest globally.
re ferd berple says:
August 13, 2013 at 6:35 am
Off topic but still somewhat relevant to posts referring to agriculture. By comparing global population to arable land utilised, it takes on average 2 hectares to feed one human.
However in India the average is just 1 ha per human whilst in China it’s 2 ha per human and in USA it’s a whopping 9.4 ha per human.
george e. smith says:
August 14, 2013 at 10:59 am
Well at the south pole, there is neither a biological cycle, nor an open water refreeze cycle.
The latter seems not right: the seasonal freezing/melting of sea ice around the South Pole seems to be larger than around the North Pole:
http://www.climate4you.com/images/NSIDC%20GlobalArcticAntarctic%20SeaIceArea.gif
Thus if the sea ice area was the cause of the larger swings, they should be larger in the SH, as less suppressed by (land) vegetation.