The report concerns work carried out by the Institute of Environmental Physics (IUP) at the University of Heidelberg in cooperation with the Royal Netherlands Meteorological Institute (KMNI), based on interpretation of methane observations made by the SCanning Imaging Absorption SpectroMeter for Atmospheric ChartographY (SCIAMACHY) instrument, one of ten sensors aboard ESA's Envisat environmental satellite.
A comparison was made between space-based methane observations and model simulations for atmospheric methane for the time period August to November 2003.
"In general the observations agree very well with the model," explains Christian Frankenberg of IUP. "For example, the measurements confirm the occurrence of enhanced methane concentrations over the Ganges plains in India as well as parts of China caused by emissions from rice paddies and domestic ruminants such as cattle.
"However in large parts of the tropics there is a considerable difference. It cannot yet be concluded which source category or combination of source categories is responsible for the discrepancy. Potential candidates include wetlands, biomass burning, termites, ruminants or a hitherto unknown source."
These results are of more than just academic interest, since methane is the second most important 'anthropogenic' or man-made greenhouse gas after carbon dioxide. Methane is among the six greenhouse gases addressed by the Kyoto Protocol that went into operation last month.
Methane traps heat over 21 times more heat per molecule than CO2. The amount of methane in the atmosphere has more than doubled since pre-industrial times, an increase att
Contact: Mariangela D'Acunto
European Space Agency