09/03/2010: Have your say on geoengineering

Geoengineering is activities to counter or reverse climate change. A survey commissioned by the Natural Environment Research Council gives you an opportunity to find out more about nine possible geoengineering techniques that could do this and asks you to say what you like and dislike about each.

This survey is currently open from 5 March 2010 to 12 April 2010.Take part here: http://geoengineering.dialoguebydesign.net

Here are some of the issues and technologies that the survey looks at:

• Carbon dioxide removal techniques (CDR)
• Air capture - Using ‘artificial trees’ to remove CO2 from the air
• Iron fertilisation - Algae grow by adding iron to the ocean. The algae absorbs CO2 from the atmosphere and sink from the upper ocean
• Liming the ocean - Adding lime reduces the acidity of the oceans, making them absorb more CO2
• Biochar - By turning dead vegetation into a fine charcoal and burying it, the CO₂ in the plants will remain locked away rather than released into the atmosphere
• Afforestation- Planting more trees to absorb more CO₂
• Solar radiation management techniques (SRM)
• White roofs - Painting surfaces of man-made structures to be more reflective would reflect heat and could lower temperatures
• Mirrors in space - Giant mirrors would act as a sunshade to reflect sunlight away from the earth and prevent warming
• Cloud whitening - Spraying seawater droplets into the air would increase cloud cover, increasing reflectivity
• Sulphate particles - Sulphur sent into the atmosphere would reflect the suns rays back into space