Washington, May 23 : A University of Leicester geographer has come up with a map that shows that about 3.5 to 4.5 million square km of the global vegetation burns every year, an area which is equivalent to the European Union (EU27) and larger than India.
The map produced by Dr Kevin Tansey, a leading scientist in the Department of Geography, shows a visual impression of the fire scars on our planet between 2000 and 2007.
"We have produced, for the first time, a global data base and map of the occurrence of fire scars covering the period 2000-2007. Prior to this development, data were only available for the year 2000. With seven years of data, it is not possible to determine if there is an increasing trends in the occurrence of fire, but we have significant year-to-year differences, of the order of 20 per cent, in the area that is burnt," said Dr Tansey, a Lecturer in Remote Sensing.
Funded by the Joint Research Centre of the European Commission, the map provides information that may be vital for scientists and agencies involved in monitoring global warming, measuring and understanding pollutants in the atmosphere, managing forest and controlling fire, and even for predicting future fire occurrence.
"This unique data set is in much demand by a large community of scientists interested in climate change, vegetation monitoring, atmospheric chemistry and carbon storage and flows," Tansey said.
As to how the information necessary for creating this map was collected, Tansey said: "We have used the VEGETATION instrument onboard the SPOT European satellite, which collects reflected solar energy from the Earth's surface, providing global coverage on almost a daily basis."
The researchers added: "When vegetation burns the amount of reflected energy is altered, long enough for us to make an observation of the fire scar. Supercomputers located in Belgium were used to process the vast amounts of satellite data used in the project. At the moment, we have users working towards predicting future fire occurrence and fire management issues in the Kruger Park in southern Africa."
Tansey also revealed those parts of the planet where the majority of fires occur.
"The majority of fires occur in Africa. Large swathes of savannah grasslands are cleared every year, up to seven times burnt in the period 2000-2007. The system is sustainable because the grass regenerates very quickly during the wet season. From a carbon perspective, there is a net balance due to the regenerating vegetation acting as a carbon sink. Fires in forests are more important as the affected area becomes a carbon source for a number of years," he said.
"The forest fires last summer in Greece and in Portugal a couple of years back, remind us that we need to understand the impact of fire on the environment and climate to manage the vegetation of the planet more effectively. Probably 95 per cent of all vegetation fires have a human source; crop stubble burning, forest clearance, hunting, arson are all causes of fire across the globe. Fire has been a feature of the planet in the past and under a scenario of a warmer environment will certainly be a feature in the future," he added.
A report describing Tansey's map has been published in the journal Geophysical Research Letters.