Durban, South Africa: The UN’s Food and Agriculture Organisation (FAO) released a new satellite-based survey, Global forest land-use change from 1990 to 2005. It provides more accurate picture of changes in the world’s forests, showing forest land use declined between 1990 and 2005. The losses in forests all around the world can now be quantified for the first time, FAO announced at COP17 in Durban, South Africa.
According to FAO’s press statement, it analysed more than 13500 high-resolution satellite images in 102 countries. The survey will help nations to accurately assess the state of their forests. Monitoring change in forests has important implications for biodiversity conservation, carbon storage and human livelihoods.
“It’s a very comprehensive study of the world’s forests. For the first time we have consistent and comparable global and regional long-term data on forest loss land use. Up until now, most available data has come in numbers, not maps (based on satellite images),” explained FAO forest monitoring scientist Adam Gerrand.
The initial findings from the high-resolution satellite data show that the world’s total forest area shrank by an average of 14.5 million hectares per year between 1990 and 2005. It largely occurred in the tropics, likely attributable to the conversion of tropical forests to agricultural land.
“The rate of forest loss has increased from 4 million hectares in 1990s to 6 million hectares between 2000 and 2005,” added Gerrand. “We are losing vital carbon storage, biodiversity and other values forests provide.”
There is some good news, too, however. The survey shows that deforestation does not happen quite as fast as countries have been reporting. The new data showed a net loss of 73 million hectares between 1990 and 2005 compared to a previous net loss estimate of 107 million hectares for the same time period. During that time, the loss of forests was highest in the tropics, where just less than half of the world’s forests are located, followed by Africa.
Asia was the only region to show net gains in forest land-use area in both periods. Deforestation occurred there as well, but the extensive planting that has been reported by several countries in Asia, mainly China, exceeded the forest areas that were lost.
All satellite images are taken 100km apart and comprise 10 square kilometres square kilometres. They are classified, labelled and then passed on to the countries where they have been taken, so that governments can review and confirm the data.