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?quality=75)
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
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
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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