Carbon cycling and sequestration opportunities in South America: the case of Brazil

A carbon emission inventory of the Brazilian agricultural sector was used to compare greenhouse gas emissions with estimated carbon offsets promoted by two main changes in agricultural management: the replacement of conventional tillage by no-tillage and the cessation of annual burning in sugar cane production. Using the IPCC revised 1996 guidelines for national greenhouse gas inventories, we estimate that 12.65 Mt C are emitted annually from agricultural land in Brazil. Ongoing conversion of conventionally tilled land to no-tillage currently accumulates 9 Mt C yr -1 . Industrial by-products like alcohol and bagasse from sugar cane processing substitute fossil fuel for transportation and power generation offsetting 10 and 8 Mt C yr -1 , respectively. An additional opportunity for 0.53 Mt C yr -1 sequestration is presented by avoiding burning before harvesting of sugar cane. These data show that there could be almost full compensation between sources and sinks/offsets in the agricultural carbon cycle. There is a great opportunity to achieve this mitigation benefit because the adoption of new technologies is increasing rapidly.