March 7th, 2015 by James Ayre
Tropical deforestation rates have actually soared over recent years, rather than decreased as was previously estimated in a prominant report from the UN’s Food and Agriculture Organization’s Forest Resource Assessment, according to new research.
The reason for this disparity is a simple one, the UN estimate was based on what people said they did, the new ones are based on what people actually did (determined via satellite imagery/data). The apparently near eternal failing of people, in other words — say one thing, do another.
The disparity in this case in huge though — the difference between a 25% decrease in deforestation (the claim), and a 62% increase in deforestation (the reality). Getting industrial culture/people to stop cutting down forests is probably like trying to get a crack addict off crack — or a flashing lights on a screen obsessed modern person to give up their ‘smartphone’, for that matter.
The new findings are based on the compilation of huge amounts of Landsat image data — there’s not really much you could argue with, the images show the uptick in rates of tropical deforestation quite clearly over the 20 year period in question.
“Several satellite-based local and regional studies have been made for changing rates of deforestation (during) the 1990s and 2000s, but our study is the first pan-tropical scale analysis,” explained University of Maryland, College Park, geographer Do-Hyung Kim, the lead author of the new study.
A recent press release provides details:
Kim and his University of Maryland colleagues Joseph Sexton and John Townshend looked at 34 forested countries which comprise 80% of forested tropical lands. They analyzed 5,444 Landsat scenes from 1990, 2000, 2005 and 2010 with a hectare-scale (100 by 100 meter) resolution to determine how much forest was lost and gained. Their procedure was fully automated and computerized both to make the huge datasets manageable and to minimize human error.
They found that during the 1990-2000 period the annual net forest loss across all the countries was 4 million hectares (15,000 square miles) per year. During the 2000-2010 period, the net forest loss rose to 6.5 million hectares (25,000 square miles) per year — a 62% increase is the rate of deforestation. That last rate is the equivalent to clear cutting an area the size of West Virginia or Sri Lanka each year, or deforesting an area the size of Norway every five years.
In terms of where the deforestation was happening, they found that tropical Latin America showed the largest increase of annual net loss of 1.4 million hectares (5,400 square miles) per year from the 1990s to the 2000s, with Brazil topping the list at 0.6 million hectares (2,300 square miles) per year. Tropical Asia showed the second largest increase at 0.8 million hectares (3,100 square miles) per year, with similar trends across the countries of Indonesia, Malaysia, Cambodia, Thailand and the Philippines. Tropical Africa showed the least amount of annual net forest area loss. Still, there was a steady increase of net forest loss in tropical Africa due to cutting primarily in Democratic Republic of Congo and Madagascar.
Commenting on the new study, geographer Douglas Morton, based at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, noted that it “really provides a benchmark of tropical forest clearing not provided by other means.”
(For a general overview of deforestation, tropical or otherwise, see: Deforestation Effects, Causes, and Examples, Top 10 List.)
Responding to criticism that the UN data was accurate and shouldn’t be dismissed, Kim commented: “We made it very clear in our paper where the FAO missed deforestation that is obvious in satellite images.”
He continued, noting that the UN FAO reported “no change of deforestation rate for 16 of 34 countries from 1990 through 2010, whereas Landsat images show otherwise”.
Seems obvious enough — if you had to guess which was more accurate, self-reported figures or actual standardized measurements, which would you trust more? A choice that becomes even easier when you consider the great incentives for those involved to underreport rates of deforestation.
“Without the transparency of Landsat satellite data it’s difficult to put your finger on changing trends.”
“Tropical deforestation has become increasingly more mechanized. In the 60s, it was axes; in the 70s, chainsaws; and in the 2000s, it was tractors.”
Given that the drivers of deforestation haven’t changed or lessened in recent years, it makes sense therefore that rates would have increased as mechanization became more common. Which is exactly what the satellite data shows.
The new findings are details in a paper published in Geophysical Research Letters, a journal of the American Geophysical Union.
Image Credit: NASA Earth Observatory images by Jesse Allen and Robert Simmon, using Landsat data from the USGS Global Visualization Viewer and park boundary data from Protected Planet
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