Chapter 5: We Are Destroying Forests & Grasslands

We humans have been destroying natural ecosystems ever since the rise of modern agriculture some 10,000 years ago. Once we learned how to cultivate plants and domesticate animals at scale, we began clearing land to make room for agriculture. Since then, we have destroyed approximately half of the world’s forests and grasslands. Similar trends apply to other equally vital ecosystems, like mangroves and wetlands.

Although we have been cutting trees down since the rise of modern agriculture, there was a ceiling to how much damage humans could inflict, since for much of this time we had no machines and there were fewer people. But in the 1700s our rate of deforestation began escalating and continued to do so until the 1980s, when we reached peak global deforestation. Half of all the forests cut down in the past 10,000 years were removed in the past century.

Since then, the rate of deforestation has slowed, meaning the pace at which we cut down forests has decreased. But we are still cutting them down—from 1990 to 2020 we destroyed over 1 billion acres of forest. In recent years, we still cut down a football field worth of trees every two seconds. As tree populations continue to decline, some tree species are nearing extinction. Botanic Gardens Conservation International completed a project in 2021 called The State of the World’s Trees, in which they found that a full one-third of all remaining tree species are teetering on the edge of existence.

A similar story has unfolded for grasslands. Consider the Tallgrass Prairies of North America, one of the most diverse ecosystems on Earth. At their peak, these prairies covered nearly 170 million acres, a vast grass sea stretching from Canada to the Gulf of Mexico. By 2003, around 87% of Tallgrass Prairies had been lost, with many of the surviving tracts in fragmented or degraded conditions. Today, the destruction continues—the National Park Service estimates that only 4% of these ecological treasures remain.

Agriculture is the biggest cause underlying this issue. We clear vast tracts of forests and grasslands to grow row crops and graze livestock. We use a shocking 50% of all habitable land (defined as land that is not covered by glaciers, beaches, or bare rock) for agriculture. More shockingly, we use 70% of all available fresh water on Earth to irrigate this agriculture, and half of that water is wasted due to evaporation and poor management practices.

That’s not all. These farming operations drench their crops in fertilizers, which pollute waterways, kill life in lakes and oceans (we call these dead zones—there is one within the Gulf of Mexico that is the size of New Jersey!), create smog, and damage the ozone layer. The fertilizers and other misguided practices lead to the death of life in soil, resulting in dirt, which easily washes and blows away. In the United States, farming operations lose 20 tons of dirt per acre per year due to erosion alone. Over time, the land becomes barren and is abandoned. A study from Stanford University estimates that there are 1 billion acres of abandoned farmland across the globe, 99% of which have occurred in the last 100 years. This land sits in ruin.

The worst part? We clear all this land, waste all this fresh water, kill soil, and use myriad chemicals to grow our food only to waste it. In the US and other affluent countries 40% of all food produced is squandered. The global average is around 17%. Meanwhile, each day, 25,000 people, including more than 10,000 children, die from hunger.

Food in general—the way we grow it, transport it, prepare it, and waste it—plays a large role in many of the issues we now face, including what some consider to be the most concerning metric: it contributes 19–29% of annual CO₂ emissions. We will address CO₂ in more detail in Chapter 8.

Let’s turn our attention to the sub/urban landscape of the United States, where we have cleared forests and grasslands to grow a different type of crop: lawns. We seed, cut, fertilize, and irrigate a whopping 63,000 square miles of lawns, an area nearly the size of Georgia. We grow more lawns than corn and devote one-third of all residential water use to keep them hydrated. Yet they produce no food! We will discuss this in more detail in Chapter 16, where we learn how to replace lawns with gorgeous, native meadows.

We also cut down forests to harvest wood. When these are ancient, untouched ecosystems, which we call primary forests, the harm is irreparable. Because these ancient forests are thousands, if not millions, of years old (the Tarkine Rainforest in Tasmania has remained largely unchanged for 40 million years), they provide disproportionately more benefits in terms of soil, food, shelter, water, and carbon sequestration as compared to young forests. No money in the world can replace the Amazon, Tarkine, and the Congo Basin. Unfortunately, we are losing these ancient forests quickly; in 2022, we cut down over 10 million acres of tropical primary forest. This is an area larger than the state of Maryland!

The net result is not good. In what is a mere two seconds on the Cosmic Calendar, we have badly damaged Earth’s ability to perform photosynthesis. Worse yet, these issues are not likely to get better any time soon. The human population is still growing and we are still cutting down trees to make way for agriculture, build sub/urban spaces, and harvest timber.

We know from Section 1 that photosynthesis is crucial to soil formation, fresh water availability, food and shelter for life, and carbon sequestration. Without trees and their photosynthesis superpowers, other systems begin to collapse. Indeed, we are seeing this with soil and fresh water availability.