Cooling Off With Compost

A simple farming technique could help mitigate the effects of climate change on crops:

The technique in question is called “no-till farming,” and it simply involves leaving the debris from previous crops on the surface of the fields rather than plowing the fields and exposing the soil underneath. Observations of test agricultural fields indicate that no-till practices have several effects. To begin with, the debris tends to retain moisture, which limits evaporation; since evaporation cools the surface, this tends to have a warming effect. But this warming is extremely limited on the hottest days, when the intense heat drives evaporation even when plant debris is present.

The agricultural debris also has an effect on albedo, the amount of sunlight that gets reflected back from the Earth’s surface. After a rain storm, the tillage was about as dark as the soil underneath it. But on drier days, the plant material reflected significantly more sunlight than the soil. This effect was amplified further on the hottest days, which are typically cloud-free, which allows the reflected sunlight to escape into space.