Shedding light on climate change

Shedding light is complicated, no matter how you look at it. In particular I have been looking at albedo, (reflected sunlight). Albedo is measured on a scale of zero to one (0 to 1, and there are phone apps for that).

How albedo affects climate depends on water vapor. The dark green low-albedo of a rainforest traps light energy near the ground, increasing humidity by triggering the cooling effect of respiring plants. At the same time, by trapping the heat near the soil surface, the atmosphere above cools, increasing the likelihood of cloud formation. Clouds have a relatively high albedo — which reflects the solar energy into space and further cools the air temperatures below, leading to lower temperatures. Lower temperatures hold less water vapor, increasing the likelihood of precipitation, hence “Rain-Forests”!

Examples of the best, most efficient spots to cool the planet are areas where albedo is high and humidity is low, like the polar ice caps and the light sands of dry deserts. The reflected energy can escape the atmosphere because humidity (water vapor) is low. Any change in albedo has significant impacts on previously stable environments.

Besides fossil fuels, manmade changes in albedo are how dirty snow, greener deserts, bare soil, and logged forests all contribute to climate change. The power relationship of albedo and water vapor, together make up the “Iron Man” suit that CO2 puts on, to be such a powerful driver of global warming on our blue water planet.

— Richard Roth, Chico