Last updated February 8, 2018 at 9:57 am
Simple actions could lower extreme temperatures by 2-3 °C according to new research.
One of the ways to cool the planet is to increase the reflectivity of the Earth’s surface, it’s albedo – the amount of light reflected from a surface.
By reflecting more solar radiation, the amount of heat absorbed by a building (or road, or pavement) can be reduced by as much as 95%.
This reduces air-conditioning costs, and can reduce the urban heat island effect.
The new study, published in Nature Geoscience, examined what effect increasing reflectivity of buildings and agricultural areas could play in mitigating climate change at a regional scale.
How do you increase solar reflectivity?
There are a few methods that the authors modelled to test the effect on solar radiation:
- No-till farming (leaving crop residues behind after harvest, which are more reflective than tilled soil)
- Timing of crop planting and harvests (eg double cropping in a year)
- Planting more reflective plant varieties
- Using greenhouses
- Increasing urban albedo with the use of reflective paints on buildings, roads and pavements.
The benefits of these methods is that they have limited negative side effects compared to geoengineering solutions like pumping aerosols into the upper atmosphere.
They can be implemented at a regional level, and these methods are much less likely to risk the international conflicts that could come from countries trying to implement global climate geoengineering plans.
They can even have co-benefits of improving soil productivity and improving crop yields for methods like no-till farming and double cropping, or reduced energy use for building with more reflective coatings. Best of all, we know they work, because we’ve seen them in action before. White roofs are common in the Mediterranean, and studies in Melbourne have shown high albedo paints will always provide a significant reduction in cooling requirements and increased comfort in older industrial buildings.
Regional scale climate engineering
This type of climate engineering in highly populated areas and agricultural areas over North American, Europe and Asia could reduce extreme temperatures there by up to 2-3°C.
“We must remember land-based climate engineering is not a silver bullet, it is just one part of a possible climate solution, and it would have no effects on global mean warming or ocean acidification.” Says lead author Prof Sonia Seneviratne of ETH Zurich.
“Regional land-based climate engineering can be effective but we need to consider competing demands for land use, for instance for food production, biodiversity, carbon uptake, recreational areas and much more before putting it into effect.”
“There are still important moral, economic and practical imperatives to consider that mean mitigation and adaption should still remain at the forefront of our approach to dealing with global warming.”