Oct. 25 (UPI) -- The clearing of forests for palm oil production has triggered rising temperatures in Indonesia, according to a new study.
Previous studies have detailed the negative consequences of land conversion and deforestation on biodiversity, but the latest is one of the first to reveal the impacts on temperatures.
"Land use change from forest to cash crops such as oil palm and rubber plantations does not only impact biodiversity and stored carbon, but also has a surface warming effect, adding to climate change," Alexander Knohl, a professor in bioclimatology at the University of Gottingen in Germany, said in a news release.
The island of Sumatra has suffered the greatest loss of rainforest in Indonesia. When researchers measured the surface temperatures of different types of land in Sumatra's Jambi province, they found clear-cut acreage was 10 degrees Celsius warmer than forests.
"Clear-cut land is the phase between forest and other land cover types, such as small-holders [small-scale family farms] or commercial plantations," said doctoral student Clifton Sabajo. "From field observations, we know that the landscape is so dynamic that there are continuous land use changes all the time, so clear-cut land is always present."
Mature palm plantations, those older than five years, featured surface temperatures just 0.8 degrees warmer than forests. Younger plantations feature hotter surfaces, as the palms' canopies are less developed, allowing more sunlight to penetrate and warm the earth.
There's also less evaporative cooling, as fewer leaves translates to less transpiration. Evaporative cooling works to keep forests cool, just as perspiration helps to cool the human body.
As detailed in their new paper, published this week in the journal Biogeosciences, scientists estimate land-use changes were responsible for 0.6 degrees of warming between 2000 and 2015. That trend is likely to continue as Indonesia continues to clear forests at rates rivaling Brazil to meet the global demand for palm oil, the world's most popular cooking oil.
"We think that current land-use developments in Indonesia need to carefully evaluate all aspects of environmental and socio-economic consequences," Knohl warned. "Land-surface temperature and microclimate should be considered."