Burning of cropland, grassland and forest has long been recognized as a significant source of carbon emissions and airborne particulates, especially in developing countries. Thus from an atmospheric perspective burning is unambiguously negative. From a land management perspective, however, the role of biomass burning in soil fertility management and ecosystem processes is more difficult to assess. Controlled biomass burning in the agricultural sector, on a limited scale, can have positive functions as a means of clearing and rotating individual plots for crop production, and in some ecosystems, as a healthy means of weed control and soil fertility improvement.
The Burned Land Area indicator (Proportion of Total Land Area Burned) is built on data taken from the Joint Research Centre’s Global Burned Areas 2000-2007 estimates, and calculated for this indicator by CIESIN Global Rural-Urban Mapping Project (GRUMP) land area and country grids. We consider a unit of land ‘burned’ if at any time during the year fire was observed. The indicator requires refinement as it currently underestimates grassland fires and does not reflect total emissions, smoke, intensity, or heat of the fires; which would help determine ecological benefits or threats.
In a number of natural ecosystems, such as savannah and scrub forests, wild fires can help maintain biotic functions. However, in tropical forest ecosystems, fires are mostly human induced and environmentally harmful, killing wildlife, reducing habitat, and setting the stage for more fires by reducing moisture content and increasing combustible materials. Even where fire can be beneficial from an agricultural perspective, fires can inadvertently spread to natural ecosystems, setting the stage for further agricultural colonization.
Given the large impacts of burning on human health, climate change, and tropical forest ecosystems that are not naturally regulated by fied, we assess fires as, on balance, a negative phenomenon from a resource management perspective. Accordingly we set a burned land target of zero. Technically a target of no burning is undesirable. We are faced with data that include a large number of countries with a small proportion of total area burning, and an absence of finer level data that could indicate whether burning occurs in a biome that is naturally fire-regulated. We set the zero target in light of these limitations.
