When someone claims that we can cool the earth safely and naturally in a decade, you would think people would be interested, right? This would be especially so when this claim comes from climate scientist Walter Jehne. I picked up Walter’s ideas from a good friend who was very patient with me because I was a bit slow to get it. Since then I have been searching for other scientists, practioners and authors who support Walter’s thinking and I have found a few.
I am encouraged when I talk with people about the idea that the best solutions for mitigating climate change are to found in nature, and the way we work with the land. A lot of people just get it, and there is no need to elaborate.
I am even more encouraged with two new recent publications that support the notion of direct cooling.
Working with plants, soils and water to cool the climate and rehydrate Earth’s landscapes
This document, by Stefan Schwarzer of the University of Geneva published by the UN Environmental Programme is available here.
The article states that around 50% of the solar energy reaching the ground is used in evapotranspiration. This heat returns to air enabling some of the heat able to escape to space. Thus vegetation cools, and when we remove it from the earth, the earth warms up. This diagram from page five of the report shows how vegetated land is significantly cooler than bare land. Read the article for a full explanation.
The impact of vegetation is also evidenced by infrared imaging. This image of a mixed landscape shows a 20 degrees centigrade difference between ashphalt and forested areas. This report deserves to be widely read.
Planting forests may cool the planet more than thought
This Princeton University article from a research team led by Amilcare Porporato is published on the Phys.org website. Essentially it claims that forests also cool by producing clouds – and those clouds cool by intercepting and reflecting solar radiation through the albedo effect. It was previously postulated that temperate deciduous forests might have a warming impact as dark coloured forests absorb heat because of their low albedo.
So more vegetation = more cooling. Trees cool in several ways:
- they sequester carbon
- they promote soil microbial activity, thus building soil’s capacity to sequester more carbon
- they create the biotic pump creating “flying rivers” transporting rain across thousands of kilometres
- they transfer heat back into the atmosphere where some dissipates into space
- they support a healthy hydrological cycle
- their aerial exudates nucleate rain.
To rapidly repair climate damage we need to look much wider than carbon dioxide.
More reading: This website includes more information on direct cooling here.