Carbon has been building up in the atmosphere. Presently, much emphasis is given on mitigation at ‘source’. But a substantial amount of carbon still remains unabsorbed and enters the atmosphere, causing global warming. This is where ‘sinks’ come in. Our objective should be to maintain a balance between the worldwide sources and sinks of CO2 so that further build-up stops. This has to be our first guiding principle to avoid global warming and prevent climate change. (Correspondence)