sink

In a climate change context, any process, activity, or mechanism - whether natural or artificial - that removes a greenhouse gas, an aerosol, or a precursor of either from the atmosphere, reducing its concentration in the air. Following the Kyoto Protocol - signed on December 11, 1997, and in force since February 16, 2005 -, there began to be increasingly frequent talk of carbon (or CO₂) sinks, both natural ones (oceans and young forests) and those proposed by geoengineering.