Why the Earth Will Heal
By Nayyer Ali MD
In my previous column I discussed how we are well on our way to solving the issue of greenhouse gas emissions and climate change. This is one of two major ecological challenges facing us this century. The other is preserving and restoring nature.
Since the environmental movement first became a political force in the 1960’s, there has been an immense sense of impending catastrophe among activists. In the 1980’s I recall dire predictions that the Amazon rain forest would be completely wiped out by 2020 due to deforestation, while many famous and beloved species like tigers, African elephants, rhinoceros, lions, polar and grizzly bears, bald eagles, the pandas of China, and gorillas would all be driven extinct. More recently, there have been some environmentalists putting forth the notion that the Earth faces a sixth mass extinction, on par with previous mass extinction events like the one that killed off the dinosaurs.
What is driving this? It is us. Humans. In the last 120 years, our numbers have soared all over the globe, from 1.8 billion people in 1900 to over 8 billion today. These billions need space to live, and more importantly, land to grow the food to feed us. This massive rise in human population over the last 12 decades has driven us to commandeer from nature vast tracts of land, driving species all over the Earth to the brink of extinction as we eat away their habitat.
This process, if it continued for another 120 years, would likely drive a major extinction crisis. But the worst has actually passed. We are already beginning the process to restore balance to the ecosystem, and make sure that the animals and plants that we share this planet with will have the room to not only survive, but thrive.
There are two main drivers of this process. First is that we have recognized that species can be put at risk by deliberate hunting, and we have moved aggressively to bring that to an end. Whales are protected around the world, and trade in endangered species like elephants and tigers is illegal. While illegal poaching still goes on, the industrialized slaughter of the past has been curtailed. Fishing in the open ocean has been an issue but adopting best practices in fisheries management allows fish stocks to rebuild while giving fishermen a reliable catch. In the US, fisheries are so well managed since 2000 that almost 90% of fish stocks are now at sustainable levels.
But the far bigger improvement is in agriculture. Humans use about half of all the habitable land surface of the Earth, but almost all of that is for food and grazing. In fact, about 30% of that land is for crops and the other 65% is for grazing livestock. The amount of land needed for human habitation is actually quite small.
There are roughly 8 billion people on Earth, and they could be comfortably housed in a land area of only 400,000 square miles, an area that is a little less than Texas and California combined. How is that possible? Because humans don’t really need that much space. For example, Paris houses about 50,000 people per square mile, while Manhattan has 70,000. Karachi has 65,000 people per square mile. Even the spread-out cities of California hold 5-10,000 people per square mile. To house 8 billion people at 20,000 per square mile divides out to 400,000 square miles. If Pakistan reaches a population of 360 million people (and it probably won’t end up that high) that still would require only 12,000 square miles of land to house people at half the density of Karachi. Which amounts to a trivial 3% of the land area of Pakistan.
Humans are impinging on nature not because of our houses and factories and office buildings, but because of our agriculture and livestock. If we use less land for that, then we can return a massive amount of land to nature. What makes that inevitable is that agricultural productivity is rising inexorably a few percent a year, while population growth has slowed down tremendously. What this means is that the amount of land we need for food and meat is going to start declining very soon and will continue to drop for decades to come. More and more land will be returned to nature as humans concentrate agriculture on the best and most productive lands.
This actually happened already in Europe and the US. A hundred and fifty years ago much of New England and New York had been deforested and converted to farmland. But soils are poor and growing seasons short compared to more southern states and the Midwest, and many of those farms have returned to nature. In the last century humans converted more and more land to agriculture to feed our rising population. This was compounded by our rising living standards, which drove much higher meat consumption. But the growth in total farmland has stopped in the last twenty years, and in the next decade we will start to see a decline in total agricultural land around the world. Poor farmers with low productivity in many Third World countries have been steadily raising their yields as they apply more fertilizer, use better seeds, and learn the latest techniques. If the world’s farmers reached the productivity of American or European farms, the amount of land that could go back to nature would be vast.
While raising productivity of traditional agriculture will have a huge impact on human land use, looking further down the road, the renewable energy revolution will also have a huge impact in a different way. For growing food, we basically need two critical inputs, water and light. If you can obtain both at a cheap price, food can be grown indoors in a building with stacks of plants going as high as you want. As solar and wind provide incredibly cheap electricity, it will be possible to obtain all the water you need from desalination, and all the light you need from LED lamps. Drug dealers have grown marijuana indoors for decades with these kinds of systems, and more recently more expensive farm products like specialty vegetables are being grown in vertical farms in some cities. But once water and light are cheap enough, this will extend to staples like wheat and rice. Food can be grown 24/7 without pesticides and herbicides, and with multiple growing seasons year-round, even in the desert or in the middle of a northern winter. This process of moving agriculture indoors will allow us to spare even more land for nature. By the end of this century, a large fraction of the human footprint on this Earth will be diminished.
There is another major trend that will further accelerate this process. This is the development of alternative sources of meat. There are two ways this is being done. First is the creation of meat-like vegetarian foods, like Beyond Beef and the Impossible Burger. These items are just the first generation, and better and more tastier versions will come along in years to come. But some of us will still want real animal muscle to eat. For that, scientists are developing lab grown animal muscle tissue for beef, lamb, pork, and chicken. The first lab grown hamburger patty cost 300,000 dollars when it was created in 2013. The current cost is about 12 dollars. Within the next decade, lab grown meat will become a commercial product, which will allow us to enjoy meat without the need for land for grazing animals, or for the cruelty of factory farming. While lab meat is still unlikely to create a chicken leg or a filet mignon, it will be a viable source for ground meat, which is how much of meat products is consumed.
If we can return even 25% of the land humans use today back to nature over the next 80 years, we will go a long way toward healing our ecosystem. It would not be a surprise at all if we exceed that number by a very comfortable margin.
