Not very long ago, tropical countries like Indonesia and Brazil has been identified as the places where the worst deforestation was going on. According to new data from Global Forest Watch, now deforestation is decreasing in the tropics, while it is increasing on the boreal hemisphere, especially in Russia, Canada and the U.S.
The Global Forest Watch is a platform that joins about 60 groups, convened by the World Resources Institute (WRI) and working in close contact with the University of Maryland and Google. The program uses algorithms that are applied to satellite imagery from NASA and the U.S. Geological Survey to estimate changes in tree cover. The project's researchers analyzed about 400,000 satellite images for the study.
The results are stunning: Russia and Canada together accounted for 34% of global tree cover loss from 2011 through 2013, losing a combined average of 26,000 square miles, or about 6.8 million hectares of tree cover each year. Tree cover loss in Russia was much larger than in Canada, by nearly double. The tree cover loss in both these countries is linked to massive wildfires in boreal forests, which span the sub-Arctic region and are comprised of tall stands of spruce, fir and larch trees.
According to a recent scientific research
published in the journal Proceedings of the National Academy of Sciences, boreal forests are burning at rates not seen for at least the past 10,000 years, with climate change projections showing the likelihood of both more frequent and larger fires to come as the climate warms and these areas experience a longer and drier warm season.
The boreal zone, which is also known as taiga, contains more than 30% of the carbon stored on land. Increased burning of these forests releases carbon into the atmosphere, helping to warm the planet, which in turn ends up favoring more fires. A spike in forest fire activity, much of it manmade, has been seen in recent years in parts of Canada and especially in Siberia, and these fires account for much of the tree loss, as well as logging activities, said WRI's Anderson.
“There’s a big debate about the exact proportion of fires that are human caused versus natural” in Russia, said James Anderson, of WRI. "Some say they’re mostly human and related to infrastructure development” Forests can grow back after fires, but boreal forest grows back at a far slower rate than tree cover does in the tropics.
Globally, the world lost more than 69,500 square miles, or 18 million hectares, of tree cover in 2013. This is about twice the size of Portugal, and is slightly lower than the loss seen in 2012. However, it is still a 5.2% increase compared to the 2000 to 2012 average, Global Forest Watch reported.
Forests are one of the planet's main carbon savings banks, sequestering carbon dioxide from the air into the soils. When trees are chopped down or burned, the carbon they absorbed is released into the atmosphere, contributing to manmade global warming.
Russia and Canada topped the list of countries with the most tree cover loss, mainly due to forest fires, jointly accounting for 34% of total loss. (Tree cover loss is a measure of the total loss of all trees within a specific area regardless of the cause.) The data show that Russia, Canada, Brazil, the United States and Indonesia make up the top five countries for average annual tree cover loss from 2011 to 2013.
Russia e Canada in cima alla lista dei paesi con il più perdita copertura arborea, soprattutto a causa degli incendi boschivi, che rappresentano insieme il 34% di perdita totale. I dati raccolti dal Global Forest Watch, indicano come la Russia, il Canada, il Brasile, gli Stati Uniti e l’Indonesia siano i primi cinque paesi per la perdita di copertura media tra il 2011 e il 2013.