Converting lands from tropical savannas to sugar cane plantations could alter the local climate.
Image: Flickr/darkinertia
At a time when Brazil is expected to bump up its sugar cane output, researchers find that converting lands from tropical savannas to sugar cane plantations could alter the local climate.
Temperatures could fall about 1 degree Celsius during the peak of the growing season and rise an equivalent amount after harvest, said researchers from Arizona State University and the Carnegie Institution for Science's Department of Global Ecology. While the results suggest that more fields of sugar cane won't drastically alter the landscape, they could affect local seasonal temperatures.
"We're basically modifying the seasonal variability," said Matei Georgescu, lead author of the study and assistant professor in the School of Geographical Sciences and Urban Planning at Arizona State University. Researchers from Stanford University also contributed to the study.
In August, the peak growing period for sugar cane in Brazil's winter, temperatures in the area around sugar cane-growing regions will be cooler. After the harvest, around December and January, the local climate warms. But on average, the experiment showed no net impacts on surface temperatures. The study was published in Geophysical Research Letters last week.
"When the crop is harvested, we are modifying the seasonal evolution. This has to be taken into consideration; you have to focus on seasons," Georgescu said.
Using regional multiyear climate models, as well as a measure of the leaf area of sugar cane, the researchers found that this local change in temperatures would not occur in the region's tropical savanna -- known as the cerrado -- where an annual harvest doesn't occur.
These temperature fluctuations are due to the albedo effect, the warming caused by the color and reflective quality of a landscape. Just as a black shirt will absorb energy in the form of heat and make the wearer feel warmer, areas of land that are dark will absorb heat and raise temperatures in the immediate climate. The bright leaves of sugar cane deflect incoming solar radiation.
The lack of leaves after the harvest also reduces the rate of evaporation, allowing the sunlight to heat the ground at a greater rate.
Cars raise demand; effects poorly understood
The scientists also found a seasonal variation in the rate of water evaporating from plants, known as evapotranspiration. With the changes in the landscape from greater sugar cane planting, there will be a 0.3 milliliter loss per day of water, on average.
The demand for sugar cane ethanol in Brazil is expected to rise this year. An increase in gasoline prices in the country will make biofuel a more attractive option. In addition, the United States continues to import the lower-carbon Brazilian ethanol to allow fuel blenders to comply with the federal renewable fuel standard. Unlike in previous years, weather conditions for sugar cane this year are looking good, so far (ClimateWire, Feb. 13).
The Brazilian sugar trade group UNICA was unable to confirm that sugar cane plantations will be expanding in neighboring savannas in the next several years.
To date, biofuel producers have yet to incorporate local effects like albedo into their sustainability metrics because of a lack of understanding on the topic, said Barbara Bramble, chairwoman of the Roundtable for Sustainable Biofuels.
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11 Comments
Add Commentit make know so much.
Reply | Report Abuse | Link to thisIt all started when President Lula da Silva said he would take the Brazilian people's off the misery by offering tax exemption and facilitating credit for the purchase of cars, people, world famous for not wearing a head mass, have the courage to finance a used car of U$10,000 in 60 installments of $ 1000, these wretches Brazilian indebted for many years, believe to be superior to other citizens, hurling violently their carts even at old pedestrians crossing the street, sporting a 'status' that only exists in the minds of those who are so ignorant to the point of ignoring the size of one's own ignorance, traffic in Brazil kills more than wars! The Sugarcane dominates every inch of land, the owner of the leased site no longer working, living with the money that gives the plant sugarcane, land used in this crop becomes sterile sand quickly, as there is only planting cane sugar throughout the country, food prices soared, basic items like rice and beans are too much work to be cultivated, prioritizing cultivation of Cana.
Reply | Report Abuse | Link to thisThese Brazilians are so strange, put fire to harvest Cana, kill all animals charred and spread a deadly dust in the atmosphere ... The Brazilians, slaves of funding foolish not imagine the evil spread by his dear president, consume the world's worst Diesel, pay times more by cars unsafe, are burdened with the second highest tax burden in the world, love music burglar (funk), poors killing others poors by soccer teams but are unable to see that their parents die in hospitals door unattended, after all, country rich is country without poverty! I ask: what is the meaning of a mailman driving a Audi of $ 100,000?
@Aleperdido
Brazil is an independent nation and regardless of what Climatewire or other foreigners believe, Brazil will do what it thinks is in their best interest. In this case they want to generate jobs and forgo having to buy fuel from other nations.
Reply | Report Abuse | Link to thisIt is interesting how western progressives feel they have the right/obligation to decide how people outside of their nation should live.
It is with great regret that I inform you that I try to live with it and this kind of people, I change brazilian people by any Hurricane, Blizzard, Tsunami, Earthquake, Sandstorm, Volcanic Eruption, Typhoon, Tsunami, Avalanche ... but no, I have the worst punishment! : [
Reply | Report Abuse | Link to thisYes, I believe that Sugarcane ethanol is an entirely uneconomical method of producing fuel, as is ALL Agro-fuels. And enormously destructive to land that would otherwise provide a rich natural environment or otherwise supply food for people. Plants are just plain horrible at converting Solar Energy to Fuel Energy, the EROEI is just so bad that it is inherently UNSUSTAINABLE.
Reply | Report Abuse | Link to thisA FAR, FAR better method is to use Agricultural, Forest, Dead Wood (i.e. pine beetle), Industrial or Refuse Organic Waste, process it in portable, transport truck sized Methanol Plants or in Large-Scale Central Plants using Nuclear Electricity, Nuclear Process Heat & Nuclear Hydrogen. That will be a 100% transfer of Organic Carbon to Liquid Fuel Carbon. The ONLY value to plants is their ability to trap atmospheric Carbon. Stupidly throwing away 80% of that Carbon as in Corn/Sugar-cane Ethanol Agro-fuels or 100% of it in Biomass Burning is inexcusable idiocy.
We need liquid fuels. That almost always entails Carbon plus Hydrogen. Organic Carbon is CO2 neutral. So you want to capture 100% of that carbon and turn it into liquid fuel carbon, as in FT Methanol Production or Nuclear Synthetic Fuels does.
Portable Methanol production from Woody Waste or Biomass, greatly reduce forest fires and the most efficient & cost effective use of Organic Waste - including Sugarcane Food Production waste:
deq.mt.gov/Energy/bioenergy/Biodiesel_Production_Educ_Presentations/KVogt_Pablo_NCAT_10_31_07.pdf
Wow! dwbd I appreciate the opportunity of to talk intelligently and even more by the valuable teachings! Is this dissemination of information and experiences that I value in this passage in the planet Earth!
Reply | Report Abuse | Link to thisMany thanks,
Alexandre
@Aleperdido
Sorry, but Brazil's contribution to changing the climate affects us all since the atmosphere does not abide by national boundries. International agreements are the best way to make sure that we don't go over the climate cliff, but trade policy is the 2nd best way if necessary.
Reply | Report Abuse | Link to this"The ONLY value to[sic] plants is their ability to trap atmospheric Carbon."
Reply | Report Abuse | Link to thisLOL!!! You DO eat every now and then, right?
Obviously I was talking about the utilization of plants for Energy applications. Carbon extraction from the atmosphere - quite impressive, Solar Energy to Biomass Energy efficiency - pathetic. You would think Sault would know that. Use some common sense.
Reply | Report Abuse | Link to thisI believe Brazil would be better off using their topical savannas for eco-tourisum, and converting their existing cane fields into solar farms. In 20 years almost all new cars will be hybrid or pure electric and the demand for cane ethanol will diminish, and demand for electricity in their electric grid will increase.
Reply | Report Abuse | Link to thisThere's an interesting link betwen this and
Reply | Report Abuse | Link to thishttp://www.scientificamerican.com/article.cfm?id=labels-that-translate-calories-into-walking-distance
We all need - in Brazil, the USA, Britain (where I am) and elsewhere - to walk more and get ourselves off our dependency on cars, whether they're run on fossil fuels or biofuel, and off our addiction to sugary food and drink. Both lead to obesity and ill-health for humans and harm to wildlife, soil, water, and climate.