World's vegetation is cleaning more carbon from skies

The Christian Science Monitor ^ | June 06, 2003 | Peter N. Spotts

[presidio9]

If your dogwoods and peony patches are looking a bit more robust than they did 20 years ago, you may have climate change to thank for much of their growth. Using two decades' worth of data on climate and vegetation, a team of scientists has taken what may be the first planet-wide look at plant activity during a time when Earth's environment underwent significant change.

The researchers found that globally, shifts in rainfall patterns, cloud cover, and warming temperatures triggered a 6 percent increase in the amount of carbon stored in trees, grass, shrubs, and flowers.

Many scientists hold that the growth in atmospheric concentrations of heat-trapping carbon-dioxide - from nearly two centuries of rapidly growing populations that burned increasing amounts of fossil fuels - is largely responsible for the earth's warming climate.

The new research adds to the body of evidence that plants can store increasing amounts of carbon from the atmosphere, but it remains unclear how long this trend will continue or whether it will significantly affect atmospheric CO2 levels.

Kyoto provisions

The 1997 Kyoto Protocols - a first step at trying to reduce emissions and so moderate the change - permits countries to use the carbon-absorbing capacity of their forests and farmlands as credits against their emissions targets. In addition, projects that increase vegetation also are seen as ways to reach national CO2 emissions targets. Thus, understanding the flow of carbon from the atmosphere to plants and back is vital to projecting future trends in atmospheric CO2 levels.

For 50 years, scientists have been measuring the growth of CO2 in the atmosphere, according to Ramakrishna Nemani, a professor in the forestry school at the University of Montana in Missoula, who led the research team. "But if you look at the record of the past two decades, the annual growth rate hasn't been going up like it had before," he says.

Other groups had forecast an increase in plant growth for a time with climate change, although rates would vary depending on region. And some smaller-scale studies had indicated that the earth was greening.

Dr. Nemani's team was interested in seeing how plant activity had changed - and where - worldwide during a 20-year period that saw two of the warmest decades ever recorded, several intense El Nino episodes, one major volcanic eruption, a 9 percent increase in atmospheric CO2 concentrations, and a 37 percent growth in human population.

The team measured how much carbon plants store after absorbing carbon dioxide through photosynthesis and returning some of it through respiration.

First, the team built maps reflecting changes in temperature, cloud cover (which affects the amount of sunlight reaching plants), and available water. Then they overlaid satellite data on net primary productivity on land and looked for relationships among these components.

Big change in the Amazon

They were stunned at the growth rates in South America's Amazon region.

"That was a big surprise," says Ranga Myneni, a botanist at Boston University and a member of the research team. Amazon rain forests accounted for nearly half the increase seen globally over the 20-year period.

The surprise was twofold. The growth rate far exceeded what most scientists expected. Many models indicated that additional growth in the tropics would be minimal, given the fairly constant temperatures from one season to the next. In addition, many researchers had held that any increased productivity in the tropics would largely be driven by a rise in atmospheric CO2 rather than changes in climate itself.

Yet the drop in tropical cloud cover during the period allowed more sunlight into places like Amazonia, Dr. Myneni says, far outpacing CO2 as a prod to growth. Likewise in other climate regions, changing Climate conditions appeared to be the dominant factor driving plant growth.

The other half of the equation

The good news for plants, which appears in Friday's edition of the journal Science, comes with caveats, Myneni cautions. Since humans collectively use about half of plants' net primary production, he says, the team's estimate of 6 percent growth over 20 years translates into a trivial 3 percent growth in material available to a growing human population.

Moreover, the 20-year period the team studied could be unusual, and hence not representative of long-term prospects for vegetation growth. And if the climate continues to warm, as many expect, plants will bump up against limits to their ability to make use of the additional water, warmth, and sunlight, just as they bump into limits on the amount of CO2 they can use. The study also doesn't answer questions about how changing climate conditions in these areas are affecting the amount of CO2 given off from plant decomposition and soil - amounts that can offset the CO2 that plants imprison in their roots, stems, and leaves.

"That's the other half of the equation" the study doesn't address, he cautions.

[Blood of Tyrants]

I has long been established that raising the CO₂ levels will cause significant increases in the rate of plant growth. The global warming chicken littles somehow conveniently forgot this point.

[jwalburg]

Amazon rain forests accounted for nearly half the increase seen globally over the 20-year period.

Oh, that's a relief. Now I won't have to keep buying shade-grown coffee!"

[Only1choice____Freedom]

You mean to tell me the Earth adjusts to changes?

That really IS news. (for some people)

[FreeTheHostages]

of course plants are a "sink" for CO2

so is the ocean

the unknown question is the capacity of these sinks

global warming from manmade causes is a *fact* -- a matter of general scientific agreement -- and we shouldn't be debating whether it exists with the Rats

rather we should be discussing what the conservative response to this fact is: market solutions rather than government-made solutions

[presidio9]

global warming from manmade causes is a *fact* -- a matter of general scientific agreement --

BZZZZZT! I'm sorry that is IN-correct.

Care to give us scientific evidence to support your belief?

[CharacterCounts]

The only "fact" I am aware of is that global warming is coincidental with changes in the Sun.

[FreeTheHostages]

Care to give us scientific evidence to support your belief?

Um, hello. The entire scientific community has reached consensus on this point. I don't think I'd even bother debating with a patzer that doesn't get that point. These threads pooh-poohing global warming are just ignorant. Smart conservatives are already moving on to market-based solutions to the rather obvious science. So, nah, I'm not feeding the trolls. I just thought I'd buzz your thread once and remind you of a little thing called "reality" and also make sure such threads contain at least one dissenting voice so that no one can say *all* conservatives are scientifically illerate.

[ElectricRook]

global warming from manmade causes is a *fact*

global warming from manmade causes is a Conclusion. Facts are things that you measure or observe. The temperature at my house in the Upper Sonoran Desert of California reached a high of 92F today. That is a FACT. I think Elvis is controlling my local temperature from his alien space ship... That is a CONCLUSION.

If you confuse Conclusion from Fact, you might also confuse Fiction from Fact.

[presidio9]

Um, hello, yourself. What you are saying is simply not true. Your "little thing called 'reality'" is an unsubstantiated theory. The fact that you are so convinced otherwise is a sure sign that the liberals have successfully brainwashed you on this subject.


God I hate it when ignorant people take a patronizing tone!

[brewcrew]

The entire scientific community has reached consensus on this point.

What the "entire scientific community" has NOT reached consensus on is the cause. To say that man can have that dramatic an effect on a natural global process would be arrogant and perhaps even blasphemous.

[jwalburg]

Joe Bastardi of accuweather doesn't buy it.

[Blood of Tyrants]

the unknown question is the capacity of these sinks

Plants are not a "sink" with a static limited capacity. They are a dynamic variable and simply keep growing. Or perhaps you hadn't noticed.

The problem with ALL people who have bought into the various liberal claptrap is that they are completely unable to grasp the cause and effect and reaction idea. For example, when taxes are lowered significantly, liberals invariably wail about lost revenue and "how are we going to pay for this" when the TRUE effect is that revenues go UP as people are encouraged th earn and spend more of their own money.

[Libertarianize the GOP]

ping

[Blood of Tyrants]

Are you talking about the same bunch of "scientists" who signed that global warming paper done a few year ago? IIRC, of the 2500 or so signatories, only about 6 were actual environmental scientists (all liberal) and the rest were noted "scientists" such as a hotel manager, grade school teachers, and generally liberal envirowackos.

[TheBattman]

What scientific agreement? You are trying to tell us that 100% of scientists around the world totally agree that global warming is a "fact"?

You might want to check your sources.

Natural seasonal and yearly changes account for far more variation in climate than any "man-made" climate changes. Right now, where I live, although it's hot, we are experiencing the coolest summer I can remember. Normally by this point (2nd week in July) we have reached 100 degrees at least a couple of times. Thus far, we have not officially been above 97 degrees.

What about the drastic temperature swings scientists claim from historical periods - like the ice ages with in-between heat spells? This was long before they claim that man caused global climate problems.

The real issue is not the use of fossil fuels and the CO2 they release, but the big question of how long will the world's supply of these fuels last. As global supplies drop and prices increase, it will make economic sense to develop other fuel/power sources. I truly believe that we will run out of these natural resources before we do any significantly proovable damage to the climate.

[The Great RJ]

There is a very interesting book recently published that has exactly recreated scenes photographed on Custer's 1875 expedition to the Black Hills of South Dakota with their modern day view. What is striking in the 1875 photos is the general lack of forests compared to the lush forests in contemporary views. Extinguishing forest fires and extensive tree planting has vastly increased forestation in this part of the world.

[farmfriend]

Rights, farms, environment ping.

Let me know if you wish to be added or removed from this list.

[Reeses]

solutions

Change can be a net good. It does not matter if change is man-made or natural, what matters is if a change a net bad or good thing. Increasing plant food, warmth, wind, and rainfall are all good things for life on Earth. Trying to lock Earth into a static state is Luddite. What is the optimum temperature and percent of CO2 wanted? The scientists never answer that obvious question. It could be we should be generating more CO2, not less. The idea that Earth must be restored to 1950 or some arbitrary time goes unchallenged yet the idea is insane.

[ggekko]

"The 1997 Kyoto Protocols - a first step at trying to reduce emissions and so moderate the change - permits countries to use the carbon-absorbing capacity of their forests and farmlands as credits against their emissions targets...."

Not only is global warming not a fact; it is the wildest sort of extrapolation based on highly complex computer models which use many assumptions that cannot be empirically verified. There is stronger evidence from temperature measuring sattellites and other temperature measuring stations not effected by urban heat island effects that the earth may be entering a secular trend toward cooling, not warming. The only real scientific fact that global warmings theorists have presented is the rise in CO2 levels; every other part of the global warming theory is pure conjecture.

One of the reasons that the Kyoto treaty was rejected so decisively by the US Senate was that Al Gore caved to the Europeans who refused to allow North America to count its status as a greenhouse gas sink againt North American greenhouse emmissions. This refusal was a blatantly political move on the part of Europeans who were pandering to their green parties. The Green Parties in Europe hate the US consumer culture and would like to see US consulmers "punished" for the sin of using "too much" gas.

The political solution for this situation is NOT TO ACCEPT the junk science upon which global warming is based. Whenever Conservatives accept politicized junk science it inevitably results in political fiascoes for the Conservative movement. President Bush has shown the way forward by supporting a revival of the US nuclear power industry which could in turn form the basis of a economically viable "hydrogen" economy.

If limited Government conservatives do not challenge the scientific basis of "global warming" theories they will eventually lose this politcal battle.