Black carbon (BC), a component of soot, is a potent climate- forcing agent and has been estimated to be the second largest contributor to global warming after carbon dioxide (CO2). Thus, addressing BC emissions should be considered an essential element of any global warming mitigation strategy. In fact, because BC remains in the atmosphere only for a few weeks, reducing BC emissions may be the fastest means of slowing climate change in the near-term. Addressing BC now can help delay the possibility of passing thresholds, or tipping points, for abrupt and irreversible climate changes, which scientists warn could be as close as ten years away and could have catastrophic impacts. It may also buy critical time to address CO2 emissions, which should remain the anchor of immediate climate mitigation efforts, but which policymakers have so far failed to address quickly enough.

Estimates of BC