As the world is not prepared to stop putting carbon dioxide in to the atmosphere, we need to also take carbon dioxide out again. Planting trees does this, although it also releases carbon dioxide stored in soil, so it is less effective than preventing the destruction of existing trees.

Even planting trees in order to chop them down and burn them in a wood-burning power station has the net effect of taking carbon dioxide out of the atmosphere, if the power station is fitted with carbon capture and storage, because the trees absorb more carbon while growing than the power station then emits.

The prestigious Royal Society produced a report in September 2009 looking at 'geo-engineering', which includes both removing carbon dioxide and other ways of cooling the planet. The Society concludes that the most promising method of geo-engineering is to capture CO2 from ambient air (carbon scrubbing). However, they point out that "at this stage no cost-effective methods have yet been demonstrated and much more research and development is needed".

The Royal Society still calls for us to try to cut emissions sufficiently so that geo-engineering will not be necessary, but it is becoming increasingly clear that it will be necessary. That is why 2% For The Planet calls on the government to spend 1% of national income on research into carbon scrubbing, to invite us all to voluntarily donate a further 1% of our own incomes to the research fund and to encourage other governments to do the same. Alternatively, a Tobin-style tax on financial transactions (also known as the 'Robin Hood' tax) of 0.05% could raise around 400 billion US dollars per year. The money also needs to be spend on carbon capture and storage and on preserving the rainforest.