I remember a teacher I had in acupuncture school saying that the Earth, being an organism, was of course subject to all the same principles as any other organism in nature. And as we’ve all sort of known for a long time, our planet is not exactly in perfect health. “It suffers from Yin deficiency,” my teacher said. “Its resources are being used up. Humans are taking far more from it than they are putting back in.”

Yin deficiency. Resources being used up. More being taken out than is being put in. That’s how it works. Yin is like fuel, like potential energy; yang is kinetic energy, energy in use. The energy in the entire universe may be infinite, or close to it, but individual organisms need to collect as much energy-producing fuel as they use up, or eventually their energy will run out. And when organisms start getting close to running out, there will be signs of trouble. There will be illness.

Yin is cool and calm by nature, so one of the most clear signs of advanced or advancing Yin deficiency is heat. My teacher made this comment about the Earth about 20 years ago. In the years since, we’ve seen glaciers melting and records breaking for high temperatures year after year. A few days ago, San Francisco broke its record for the highest temperature EVER recorded there, and in my home this week, we’ve been told to stay indoors if possible to avoid inhaling the smoke from some of the roughly 1,000 wildfires currently burning in the western U.S. The temperature of the sea is rising, and we’re watching the most catastrophic hurricane season in American history.

Chinese Medicine also has the term “Yang excess.” This basically means too much energy in use, too much happening at once. That causes heat too. So if you have both an excess of Yang, and a deficiency of Yin at the same time, you end up with a dangerous amount of heat.

These are simple lessons to learn, but important ones: You’ve got to feed your body (or your garden or your planet) good food if you want it to keep giving. And if, at the same time, you put a lot of hot, toxic materials into your body or your environment, you’re going to eventually go up in flames in some form or another. Fortunately, imbalances can almost always be corrected and re-balanced, though when you wait too long to address them, successful treatment becomes a lot more difficult.