To avoid real action at CO2 producing economies at home, the industrialised countries have come up with other ideas on how to decrease global CO2, e.g. by reducing CO2 elsewhere or declaring forests
as 'carbon sinks' to reduce CO2 concentration in the atmosphere.
'Carbon sinks' reduce CO2 not by cutting emissions but by soaking it up: Grow a big forest and get rid of tons of carbon bound in the trees. But this CO2 could anytime be released again if the trees are burnt or cut down. Even worse, naturally grown forests, rich in biodiversity, might be replaced by monoculture plantations, which appear to be more effective in soaking up CO2.
However, planting trees rather than reducing emissions from fossil fuels will not save the global climate. For one thing, it is scientifically proven that the biosphere cannot store all the carbon we could release, which is currently underground in the form of oil, gas and coal ("saturation"). Also, there are huge uncertainties and accounting problems involved with the use of sinks to meet the targets. And if, as science indicates, forests globally will become sources of greenhouse gases rather than sinks --how can we be sure that a forest project will actually reduce the amount of greenhouse gases in the atmosphere in the long run?
Planting trees is also not necessarily environmentally friendly: a monoculture plantation soaks up much more carbon than an old-growth forest but might destroy biodiversity. In the long term, we cannot rely on trees and soil to soak up carbon, but we must stop burning fossil fuels.