Are Our Leaders Confused About Why Things Are Heating Up?
This past week we saw the devastation of fires that ripped through Northern California, Spain and Portugal. On one hand, these fires could be dismissed as seasonal. But on the other, some people in the climate movement, including Al Gore and California Governor Jerry Brown, blamed the fires on a changing climate. It turns out that both things may be true, but not in the way you might think.
You’ve probably heard of the “heat island effect.” It’s a phrase that usually refers to a city that is getting progressively hotter. The causes seem pretty simple: lots of asphalt and not a lot of trees. But upon deeper investigation, this phenomenon is at the root of a cascade of localized environmental phenomenon, including less rain, increased heat waves and the perfect conditions for large wildfires. And believe it or not, the heat island effect is far more prevalent outside of cities than in them. Here’s why…
The sun emits radiation, not “heat,” as we often think. If the sun’s radiation falls onto water, it can cause evaporation. But if it falls onto land, it has only three pathways. Solar radiation can be absorbed into the surfaces onto which it lands, it can be reflected back into the atmosphere turning into heat or, if it falls onto plants, it can cause photosynthesis and “evopotranspiration.” In a healthy ecosystem, most of the land is covered by some form of plant growth. This can include trees, shrubs, brush and grasses.
As solar radiation hits the leaves of these green living things, it is absorbed and transferred to chemical energy. It also causes water to be transpired through the leaves of plants. The water vapor cools the localized area and turns into dews, mists and fogs that contribute as much as 40% of the precipitation of an area. This is called the “small” or “short water cycle.” (As opposed to the “large” water cycle we learn about in school in which ocean water turns into clouds).
When we clear land of brush and instead create open and bare spaces, we stop the small water cycle. Less evopotranspiration means less light precipitation. Because plants are not absorbing solar radiation, that radiation now has only two pathways: absorption and reflection, both of which result in localized heat. Hence, the “heat island effect.” The problem is, when we clear massive regions of plants, the heat islands look more like vast solar ovens stretching for hundreds or even thousands of miles. The hotter the land itself and the hotter the air above it, the less condensation can occur. Essentially, bare areas push clouds away. Hot, bare areas beget more heat and the plants that do exist become more brittle, drier and more easily combustible.
Nowhere is this more prevalent than in most of the places we practice agriculture. Take California’s central valley as an example. It is an 18,000-square mile solar oven which has been denuded of its former oak savanna and wetlands. This is where the soil comes in. In a natural ecosystem, the soil will store between 100,000 gallons per acre all the way up to 200,000 gallons per acre depending on the soil type and ecosystem. That water is stored in the carbon formations in the soil created by microbes, just like a sponge stores water. In a healthy ecosystem with plants evapotranspiring water and soil that is moist, fires still happen, but they eventually burn themselves out.
The good news is we can restore the water cycle, restore the water holding capacity of our soils and regrow areas that have been damaged by fires so they are more resilient, moist and cool. The way to do this is by working through the lens of the soil. This means no bare spots (even between rows of trees, or in the case of Northern California, grape vines.) It means not tilling the soil, not applying heavy pesticides and diversifying crop species so the varying depth of plant roots push both carbon and water into the soils.
Two of the greatest examples of land regeneration are in France and in China. In France, the Landes Forest stands on an area that was completely denuded by early agriculture. Some of that denuded land still remains and the difference between the barren land and the forest that was later replanted is as stark as night and day. One can see it at the dune du Pilat et Landes de Gascogne where there is a sharp division between sand and forest.
Another example of ecosystem restoration comes through the work of John D. Liu who was involved in a multi-decade project at the Loess Plateau. The land of the region had been completely degraded by human intervention. It was dry and barren. Just rock and bare dirt. The Loess Plateau today is a thriving and beautiful ecosystem in which humans live and practice agriculture.
We can and should regrow California’s fire ravaged lands. And when we do it, we should make sure that the soil, the small water cycle and the plants are the focus. Doing so will ensure we have greater localized precipitation, lower temperatures and a more resilient ecosystem. Ultimately, we face big climate issues. But we can start locally, plant trees and other perennials, heal our soils and protect our loved ones and families using nature.
To learn more about what’s really in your food and get a complete guide to the new “regenerative diet,” pick up a copy of Josh’s new book, Kiss the Ground, How the Food You Eat Can Reverse Climate Change, Heal Your Body and Ultimately Save the World. More info at: www.KissTheGroundBook.com
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