Climate Sustainability

Looking back at the present moment from a thousand years in the future highlights sustainability: we can’t keep indefinitely increasing harms we do to the Earth. Even small increases eventually add up. If we keep increasing the amount of land we use for housing, for example, by one percent per year, the increases will compound into a 20,959-fold increase in a thousand years.

There are many environmental increases that are not sustainable: the concentration of greenhouse gases in the atmosphere, the amount of land that’s used for human purposes, and the population of the planet, just to name a few.

Businesses profit from these increases. We keep building more housing and developers make big profits. We keep burning oil and gas and the oil companies make big profits. Businesses know that the status quo is not sustainable and therefore can’t last; they just want to be allowed to continue making money for a while longer — as much longer as possible. They’re like the fat guy who eats enough to gain a pound a month. He knows he has to cut back, but keeps putting off the date when he’ll start his diet in earnest so he can enjoy good eating a bit longer.

Sustainability seems to be still somewhat in fashion among environmentalists, though it’s getting a bit passé. Environmentalists are herd creatures. The Chief Development Officer of one of the world’s largest environmental organizations told me that foundation funders follow trends and fads like 13-year-old girls. And big environmental organizations tend to do what the foundations want them to. A lot of the issues that were once front-and-center, and from which the environmental community has largely moved on, are still important issues, like preservation of public lands, population, and nuclear weapons. Environmentalists seem to be moving on and not talking much about sustainability, though it’s an important lens through which to view many environmental issues.

The UN Sustainable Development Goals were adopted by all UN member states at the 2015 Sustainable Development Summit in New York. They include social and economic goals, such as ending poverty and hunger, in addition to environmental goals such as clean energy and climate action. In typical U.N. fashion, an entire mini-industry has sprung up around the effort, with conferences, synthesis reports, and sessions at the climate-change COPs. But the SDGs are wonderful goals, and they have my wholehearted support.

Growth Cannot Continue Forever

Even small yearly increases turn into huge increases when compounded over a long period of time. As mentioned above, a one-percent every year will compound into a 20,959-fold increase in a thousand years. So we can’t afford, over the long run, even small yearly increases in our impacts on the environment.

If our depletion of Earth’s resources was at a low enough level, we could afford to wait to start ramping our impacts down to a sustainable level. But that is not the case. We’re already using more land than we should be using, for housing, agriculture, and other development. We’ve depleted supplies of fresh water to the point of scarcity in many parts of the world. And we’ve already emitted enough greenhouse gases to seriously harm the planet. This is an emergency! We can’t instantly cut all these impacts back to the required level (zero, in the case of GHGs), but we can plan to ramp them all down to a sustainable level over the next few decades.

The two main drivers of human environmental impact are population and per-capita consumption. The product of these two numbers is roughly proportional to humans’ environmental impacts.

Population

It used to be OK for environmentalists to discuss population, but recently it’s become fraught with racial implications and thus taboo. The idea seems to be that rich white environmentalist men in developed countries shouldn’t be telling poor women of color in developing countries how many babies they can have. When framed this way, I agree. This formulation also gets to the other aspect that make the issue uncomfortable: if we decided that global population needed to be reduced, how could we do this in a way that is fair, equitable, and non-racist?

Religions traditionally oppose population control, for doctrinal reasons, and because they extend their influence by increasing the ranks of the faithful. They encourage their believers to breed. The basis for this seems to be that they want to leave the decision whether to create a new human life to God. This reasoning should have no place in formulating public policy.

World human population is about 7.8 billion as of this writing. The UN’s medium projection is that this figure will increase to 10.9 billion by 2100. Much of this growth will be in Africa. The 2100 projection exceeds most estimates of the carrying capacity of the Earth — between 4 billion and 9 billion persons. The good news from the UN’s report is that they expect population growth to slow down considerably by the year 2100. The bad news is that the population level projected for 2100 may be unsustainable.

Why shouldn’t we consider what would be the optimal population for this planet? If we could gradually reduce the population to 5 billion, say, we would put a lot less strain on Earth’s limited resources, and everyone could have a better life. Is there a downside to such a plan? We need to stabilize the population because growth can’t continue forever. At some point, if we keep growing, we will exhaust the Earth’s limited resources.
My upcoming book, Earthling, will have a chapter on the many ethical issues relating to population.

Economic Growth

The other factor in causing environmental harm is consumption. We all consume too many resources, at a rate that is not sustainable. This is much truer for folks like me who live resource-heavy lifestyles in developed countries. GDP is a good proxy for consumption, though not exactly right, since some income is saved and not spent for consumption.

Worldwide, GDP has grown by roughly a factor of 20, since 1950, roughly a 4% average annual increase. That’s a big benefit for us — our lives have been improved by all the extra goods and services we’re receiving. Economists and politicians consider GDP growth the leading measure of economic health. The economy is strong when it is growing.

But economic growth, to the extent it’s based on population and consumption growth, is unsustainable. Developers make a lot of money building new houses on vacant land. Where I live, in Southern California, developers are sprawling out huge developments into river valleys and grasslands, which should be left as open space. In a sustainable world, we would not allow new houses to be built on vacant land because we can’t indefinitely increase the land we use for housing. If the population weren’t growing, we wouldn’t need any new housing anyway — just replacement housing.

In a sustainable world, economic growth will come from increases in efficiency; we can get more outputs from the same inputs if we are more efficient. Other than that, the economy will be steady-state, and the yearly GDP increases will be very modest. This would be bad for business, but good for humans and the planet.

Will Technology Save Us?

There is a school of thought holding that we ought not to worry so much about the environment, because technology will save us. Look how much we’ve advanced in the last thousand years, with the invention of cars and planes, TV and the Internet, steel and skyscrapers, and computers. There is no way a person in the year 1010 could have envisioned all this or anticipated how this technology would solve long-standing problems. Just trust that technology will take care of everything.

As an example those who think technology will save us point to Paul Ehrlich’s 1968 book, The Population Bomb. They call out its prediction of worldwide famine in the 1970s and 1980s due to overpopulation. But the agricultural green revolution came along and allowed farmers in developing countries to greatly increase their yields, so Ehrlich’s dire predictions never came to pass. As technology saved the day for agriculture, they expect it to fix the climate crisis and other environmental problems.

The oil and gas companies are touting negative-emissions technologies, as they claim that carbon management will become an important part of their business. We shouldn’t worry, they say, because they’ll come up with technology to solve the climate crisis, so we don’t have to stop burning fossil fuels. This is pretty pie-in-the-sky. The IPCC refused to consider negative-emissions technologies in their Production Gap Report, due to “multiple feasibility and sustainability constraints.” (p.14). Until a negative-emission technology is proven to be effective and affordable, there is no technological solution to climate change in sight, and we must assume that none will be developed. The precautionary principle says we shouldn’t count on uncertain solutions to environmental problems.

Reversibility

Human’s ability to do long-term harm to Earth came with the industrial revolution, starting in the 19th century. Before that, we’d changed the planet through agriculture, but that change is easily reversible: leave the fields alone for 50 years and they’ll revert back to close to their natural state. During thousands of years before the industrial revolution we became accustomed to exploiting Earth’s resources without worrying about whether it would harm the planet, because we saw those resources as inexhaustible. We didn’t need to even think about sustainability.

But now we do. Now we are pumping enough carbon into the atmosphere that we’re heating up the planet, with all the follow-on consequences: increased storms and droughts, the loss of many species of plants and animals, and sea-level rise, among others. These changes are, in effect, irreversible. Species take millions of years to regenerate. CO2 cycles out of the atmosphere very slowly; it takes hundreds of years.

When people in 3030 look back a thousand years to 2020, they will see a critical time when we could have stopped burning fossil fuels and therefore stopped the accumulation of greenhouse gases in the atmosphere. There is no question we will stop burning fossil fuels eventually, because burning them is not sustainable. We have already caused over 1˚C of heating; this is the global average, and warming in the Arctic is already twice this. The impacts and costs will keep getting worse until we stop. At what point will we stop? We seem to be on a path to 4˚C of heating, which would be catastrophic, not just for us, but for many generations to come. There’s still time to limit the heating to 2˚C if we act decisively now.