It has long been known that changes in land use can affect local temperatures. Switching from forest to pastureland to a concrete jungle has a measurable effect. Here, we see that the type of crop associated has a dramatic effect:
The scientists found that converting from natural vegetation to crop/pasture on average warmed the cerrado by 2.79 °F (1.55 °C), but that subsequent conversion to sugarcane, on average, cooled the surrounding air by 1.67 °F (0.93°C).
Via Eurekalert: Sugarcane cools climate
Palo Alto, CA—Brazilians are world leaders in using biofuels for gasoline. About a quarter of their automobile fuel consumption comes from sugarcane, which significantly reduces carbon dioxide emissions that otherwise would be emitted from using gasoline. Now scientists from the Carnegie Institution’s Department of Global Ecology have found that sugarcane has a double benefit. Expansion of the crop in areas previously occupied by other Brazilian crops cools the local climate. It does so by reflecting sunlight back into space and by lowering the temperature of the surrounding air as the plants “exhale” cooler water. The study is published in the 2nd issue of Nature Climate Change, posted on-line April 17.
The research team,* led by Carnegie’s Scott Loarie, is the first to quantify the direct effects on the climate from sugarcane expansion in areas of existing crop and pastureland of the cerrado, in central Brazil.
The researchers used data from hundreds of satellite images over 733,000 square miles—an area larger than the state of Alaska. They measured temperature, reflectivity (also called albedo), and evapotranspiration—the water loss from the soil and from plants as they exhale water vapor.
As Loarie explained: “We found that shifting from natural vegetation to crops or pasture results in local warming because the plants give off less beneficial water. But the bamboo-like sugarcane is more reflective and gives off more water—much like the natural vegetation. It’s a potential win-win for the climate—using sugarcane to power vehicles reduces carbon emissions, while growing it lowers the local air temperature.”
The scientists found that converting from natural vegetation to crop/pasture on average warmed the cerrado by 2.79 °F (1.55 °C), but that subsequent conversion to sugarcane, on average, cooled the surrounding air by 1.67 °F (0.93°C).
The researchers emphasize that the beneficial effects are contingent on the fact sugarcane is grown on areas previously occupied by crops or pastureland, and not in areas converted from natural vegetation. It is also important that other crops and pastureland do not move to natural vegetation areas, which would contribute to deforestation.
So far most of the thinking about ecosystem effects on climate considers only impacts from greenhouse gas emissions. But according to coauthor Greg Asner, “It’s becoming increasingly clear that direct climate effects on local climate from land-use decisions constitute significant impacts that need to be considered core elements of human-caused climate change.”
*Co-authors on the study are David Lobell of the Program for Food Security and the Environment at Stanford University, Gregory Asner and Christopher Field of Carnegie’s Department of Global Ecology, and Qiaozhen Mu of the University of Montana. The work was made possible through the support of the Stanford University Global Climate and Energy Project.
The Department of Global Ecology was established in 2002 to help build the scientific foundations for a sustainable future. The department is located on the campus of Stanford University, but is an independent research organization funded by the Carnegie Institution. Its scientists conduct basic research on a wide range of large-scale environmental issues, including climate change, ocean acidification, biological invasions, and changes in biodiversity.
The Carnegie Institution for Science (www.carnegieScience.edu) has been a pioneering force in basic scientific research since 1902. It is a private, nonprofit organization with six research departments throughout the U.S. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.
Smokey says:
April 18, 2011 at 5:21 am
“Real world evidence confirms that CO2 is harmless and beneficial. More of this minor trace gas is better. If anyone has evidence to the contrary, please present it. Evidence, not speculation, please. We have had enough baseless “carbon” speculation.”
Right on Smokey.
We are all tired of the constant referrals to “carbon footprint”; “CO2 emissions”; “CCS”; “Burning fossil fuels” etc….when the whole IPCC CAGW theory has been debunked.
Latitude says:
April 18, 2011 at 5:17 am
” Let’s see here….
So a study funded by who knows, comes out saying sugar cane is good…
….Soros is the largest investor in Brazilian sugar cane for ethanol
http://www.grist.org/article/george-soros-vs-the-planet
I don’t see a connection there, do you?”
Great observation Smokey. Keep up the good work.
Cock and Bull story in the Telegraph:
The head of the Met Office, John Hirst, has revealed that he has received death threats from climate change sceptics.
http://www.telegraph.co.uk/earth/environment/climatechange/8458162/Met-Office-chief-receives-death-threats-from-climate-change-sceptics.html
A Met Office spokesman confirmed Mr Hirst had received death threats made in a number of ”unsavoury emails”, but said they were ”isolated incidents” and the organisation had not felt it necessary to involve the police.
I call bull on this story. Because the death threats were ”isolated incidents” the Met Office had not felt it necessary to involve the police, such total and utter crap. Do we take if from this bogus statement that for the Met Office to consider a death threat a serious threat it has to come from various sources at one time. Laughable.
Willis Eschenbach says: April 18, 2011 at 1:20 am
‘Sugar … is there nothing it can’t do?’
Yep, it ain’t fixed the massive shanty towns/squatter settlements (barraidas: 1952 studies-faveals: 1940 studies onwards) and lack of property rights in the outer areas of these Sth American cities. Though there is reported extraordinary organisation and tertiary education leading to employment in the urban centres by some, despite the continuing poverty and distress amongst the majority of these population in many instances.
Stephan says: April 18, 2011 at 6:22 am
‘Brazil fixed its automotive fuel scarcity by finding offshore oil.’
Thank you.
if sugar cane makes the air cool, I can’t imagine how hot south Luzianna must have been before they started growin’ it there!
Apologies, correction- spello
favela(s)
The posters here who have accused ‘science’ of dealing in contradictions when this research finds cooling with increased levels of plant transpiration, and think this is in contradiction with the GHG effect of water vapour in warming the surface are exhibiting their own ignorance and revealing a defect in understanding – not in the science.
One is a local effect, the other is global.
Izen says:
“One is a local effect, the other is global.”
Like the Arctic ice decline compared with global temps?
Is that Izen’s ignorance? Or just a defect in his understanding?
izen,
burning gasoline does not “artifically” release CO2 back into the atmosphere … oil seeps into the oceans everyday and is consumed i.e. released into the carbon cycle and has for hundreds of thousands of years … we are simply speeding up that release … nothing artifical about it …
otherwise very informative comment …
It just occurred to me that the people now in the Carnegie Institution for science would have put the man who founded the institution that bears his name, Andrew Carnegie, out of the steel business for environmental reasons. Although Andrew Carnegie was a generous man I don’t think he was that generous.
According to Wikipedia the official name of the Carnegie Institution for Science is still officially and legally the Carnegie Institution of Washington.
“temperature can can cool as transipriation increases, the actual heat content of the air per kilogram can be higher due to the added water vapor; e.g. see
Pielke Sr., R.A., C. Davey, and J. Morgan, 2004: Assessing “global warming” with surface heat content. Eos, 85, No. 21, 210-211. http://pielkeclimatesci.wordpress.com/files/2009/10/r-290.pdf
Only if an albedo change is large enough such that the net radiation received at the surface is sufficiently reduced, will there be actual cooling.”
WRONG.
phase change and density, my man. it makes a heat pump to the stratosphere.
do the calculations sometime.
mark says: “you’re on shaky ground here. land management and these stats are as contentious as cagw.”
Who is this “you” of which you speak? What are you trying to say?
I think that all stations used in calculating “global temperature anomaly” have warming bias (net warming). I am not sure how UHI is exactly defined, but I think this term is misleading. It is not only URBAN! Even the most rural stations have warming bias, maybe tiny and negligible but still.
I think this effect should be called ALW (anthropogenic local warming). It is very real, contrary to the global one.
Maybe warmists will accept that. They get their anthropogenic warming:)
Burning ethanol makes proportionally more local water vapor, a much stronger “greenhouse gas” than CO2. The world has gone mad.
Well that was easy enough:
“from the Carnegie Institution’s Department of Global Ecology”
Who received funding from “Climate Policy Initiative”
“The Climate Policy Initiative is being funded by the Soros Foundations Network”
Soros owns the largest sugar cane fields and processing plants in Brazil.
izen says:
April 18, 2011 at 8:01 am
“The posters here who have accused ‘science’ of dealing in contradictions when this research finds cooling with increased levels of plant transpiration, and think this is in contradiction with the GHG effect of water vapour in warming the surface are exhibiting their own ignorance and revealing a defect in understanding – not in the science. One is a local effect, the other is global.”
Izen, Sweety, the Warmista are so blindly obsesessed with “the cloud of CO2 that envelops Earth and the cloud of water vapor that it creates” that they can no more distinguish between local and global than they can between weather and climate. They have assumed, purposely, that climate is the CO2 cloud (as in climate = CO2 cloud) and that weather is local (as in weather = local). That is why they cannot imagine how anyone could believe that UHI affects climate. However, by severing all empirical ties between climate and weather, between CO2 cloud effect and local effect, they have locked themselves away from all empirical evidence and into the purely mental world of novel statistical technique.
If we could convince the farmers around Mt. Kilimanjaro to stop growing food crops and switch to sugarcane, it would cool the area and return moisture to the air. Would Big Sugar then be blamed for saving the snows on Kilimanjaro?
“Brazilians are world leaders in using biofuels for gasoline.”
I just love how the libz/greens trot out this canard. People like Bill Mahre that trot out this canard are comparing apples to oranges.
#1 Fuel for cars is still higher cost in Brasil than in the USA.
#2 Per Capita car ownership is vastly lower in Brasil than the USA.
#3 The amount of car fuel consumed in Brasil is vastly less than the USA.
#4 Brasil has about 55 -60% of the population of the USA.
#5 Brasil has no interstate highway system to speak of. People don’t travel much by automobile to different regions of the country.
#6 Most of the People (except the rich) that are lucky enough to have cars have little compact cars, which are not popular nor have much utility in the USA.
#7 Much of the interior of Brasil is basically in 3rd world conditions.
“It does so by reflecting sunlight back into space and by lowering the temperature of the surrounding air as the plants “exhale” cooler water. ”
Color me confused. I thought water vapor was a greenhouse gas.
“ew-3 says:
April 18, 2011 at 9:39 am
“It does so by reflecting sunlight back into space and by lowering the temperature of the surrounding air as the plants “exhale” cooler water. ”
Color me confused. I thought water vapor was a greenhouse gas.”
Me too. If water vapor is a greenhouse gas then burning ethanol is counterproductive to the AGW warm-mongers goals. If the water vapor forms clouds at night I know it traps heat, if it forms them in the daytime then it reflects sunlight. If it does not form clouds then I don’t know what it does.
Izen,
But the global is the sum of the locals. Raising the atmospheric H2o in a local situation will necessarily raise the global H2O unless you postulate that there is a concurrent drop in H20 elswhere to counter balance the raise. Nothing here would imply that.
Since then the local H20 is rising then global H20 would rise, therefore there would be more greenhouse warming. This directly contradicts what the authors claim.
Unless you claim that the extra H2O greenhouse effect cools locally but causes warming where the H2o isn’t.
CO2 is less when burning sugar-fuels? Considering that sugar which consists only of carbon, hydrogen and oxygen, it would ultimately breakdown into CO2 and water and carbon. Nobody would use sugar directly because the carbon residue would destroy an engine (that old sugar in the gas tank idea) and the delivery system would be problematic. They must really mean alcohol derived from cane sugar. Molecule per molecule alcohol may produce less CO2 than gasoline but it’s less efficient thus more of it must be burnt in the long run.
Willis Eschenbach: April 18, 2011 at 1:20 am
‘Sugar … is there nothing it can’t do?’
Won’t cure diabetes but can do everything else 😉
@-Smokey says:
April 18, 2011 at 8:11 am
“Like the Arctic ice decline compared with global temps?”
The link you give to global temperatures is cherry-picked somewhat. It shows the cooling from an El Nino to a La Nina over less than 2 years that is almost as great as that seen in 98-99.
The result is that minimum lower troposphere temperatures are now only slightly higher than the MAXIMUM temperature during the early 1980s.
Both Arctic ice and global temperature show the same consistent trend over decadal timescales, with short-term fluctuations at the annual level.
@-Jeff Carlson says:
April 18, 2011 at 8:12 am
“burning gasoline does not “artifically” release CO2 back into the atmosphere … oil seeps into the oceans everyday and is consumed i.e. released into the carbon cycle and has for hundreds of thousands of years … we are simply speeding up that release … nothing artifical about it … ”
Baloney.
Exxon and BP are not ‘speeding up’ a NATURAL release of oil that seeps from geological faults, the extraction process is entirely artificial and several orders of magnitude greater than any natural seepage. Trying to equate the natural rate of sequestration and release with the VASTLY greater rate of emission from burning fossil fuels from deep sequestered carbon is either duplicitous or stupid.
@-Sam Parsons says:
April 18, 2011 at 8:50 am
“Izen, Sweety, the Warmista are so blindly obsesessed with “the cloud of CO2 that envelops Earth and the cloud of water vapor that it creates” that they can no more distinguish between local and global than they can between weather and climate. …. they have locked themselves away from all empirical evidence and into the purely mental world of novel statistical technique.”
Sam, darling, blaming the warmista for their misconceptions does absolutely nothing to absolve the rejectionists from their idiocy.
izen says:
April 18, 2011 at 11:05 am
“Baloney.
Exxon and BP are not ‘speeding up’ a NATURAL release of oil that seeps from geological faults, the extraction process is entirely artificial and several orders of magnitude greater than any natural seepage. Trying to equate the natural rate of sequestration and release with the VASTLY greater rate of emission from burning fossil fuels from deep sequestered carbon is either duplicitous or stupid.”
Doesn’t compute.
http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/earth_system/hydrologic_cycle.html
In response to comments like
“Burning ethanol makes proportionally more local water vapor, a much stronger “greenhouse gas” than CO2. The world has gone mad.”
“If water vapor is a greenhouse gas then burning ethanol is counterproductive to the AGW warm-mongers goals. ”
You need to look at the big picture.
* Before the growing season, there was CO2 & H2O in the air.
* During the growing season, the plants took that CO2 & H2O, making sugar (and other organic materials) from which people made fuel.
* After the growing season, the car burns the fuel, and we end up with CO2 & H2O in the atmosphere. The net change is zero.
There will be some minor changes in WHERE the CO2 and H2O are. There will not be any MORE water created by burning biomass. And water maintains are relatively stable balance because of evaporation & precipitation, so any local changes would be fairly short-lived. Changes in CO2 would take longer to return back to balance
(There WILL be more water and CO2 if you burn fossil fuels, since that C & H was taken out of circulation millions of years ago. )
izen says:
“The link you give to global temperatures is cherry-picked somewhat.”
The link was to a graph by Bill Illis, who is anything but a cherrypicker. Not even ‘somewhat’.
And according to you, scientific skeptics are now “rejectionists”? Your problem is that per the scientific method, you have failed to show that CO2 is a problem, or that AGW even exists, never mind the thoroughly debunked CAGW conjecture. In other words, you’re operating on a belief system. That triggers the nod reflex at RC and CP, but it fails here at the “Best Science” site, where evidence and the scientific method rule.