Photograph of a Vietnamese farmer near Châu Đốc in An Giang province, southern Vietnam, in the Mekong Delta on the border of Cambodia. Intermediate step between harvesting and seeding, the farmer here burns his field to clear it with less effort. This is indeed a very effective and quick technical, but slash-and-burn agriculture is also ecologically controversial because it encourages global warming by the significant release of CO2 emissions into the atmosphere, also contributing to the depletion of soils.