Life helps climate cool

Nice to see an article today by Rob Lewis on the impact that life can have on cooling our climate, and that builds on some of my writings. He writes:

"This little drawing is by Alpha Lo, author of the Climate Water Project, provided as part of a three-piece series he’s written called Biodiversity Regulates Climate. Lo takes the reader on a mind-bending tour through the laws of thermodynamics and entropy to show how a biologically run climate makes perfect physical sense. Such laws can be difficult to grasp, but Lo brings them down to (and into) Earth, condensing the discussion into a single phrase which he repeats throughout like a mantra: energy flows, matter cycles.

Let’s look at Lo’s drawing with this mantra in mind. Most of us already know that plants, through photosynthesis, transform sunlight into chemical energy which then flows into and powers the plant’s growth. If we drew a deer beside the plant and a cougar beside the deer, we’d see the energy flow laterally, into and through the living landscape, as matter cycles from plant to deer to cougar. But in Lo’s drawing energy doesn’t flow into the system but out, sent on a U-turn straight back up to the sky.

And what is cycling? Water, in all its phases, up and down, liquid to vapor to ice to liquid again. The water cycles round and round and heat flows up: a plant-driven heat pump. Here’s how it works.

The cycle begins in the soil, which, if healthy and naturally vegetated, soaks up rainwater like a sponge while at the same time feeding aquifers. That’s good because the plant, grass or tree will need that water in the hot summer when the sun is strongest. And a lot of water is needed, over 100 gallons per day for a typical tree. About 90% of that water is brought to the undersides of its leaves, and exuded through pores in a process much like sweating called transpiration. Anyone who’s worn a sweat dampened t-shirt in the wind knows the cooling effect of evaporating water.

The process is cooling because the phase change from liquid to vapor requires heat. At the moment liquid water evaporates to vapor, heat flows into the vapor as kind of potential, called latent heat. Since water vapor is lighter than air, the vapor rises, eventually condensing to clouds and back to liquid again, as rain, at which point the heat is released, only higher in the amosphere. As the small water cycle wheels around, it pulls heat from the lower atmosphere where CO2 is more concentrated, to the upper atmosphere where CO2 is slightly thinner, the air is colder and the heat is that much closer to space and final escape. It’s estimated a typical tree has the cooling power of two 5-star hotel refrigerators, but rather than sending the heat out the window into someone else’s air, it sends it up out of the living space.

It’s a living heat pump with a beautiful logic—the more water cycled the more heat removed. Add the fact that the more life growing in a landscape the more water it can cycle, and you arrive at simple formula: to cool the planet grow and protect more life."

You can read the rest of Rob Lewis's article here https://theclimateaccordingtolife.substack.com/p/the-earth-is-not-a-person-sleeping