COPENHAGEN — According to conventional wisdom, we are voraciously using the world’s resources and living way beyond Earth’s means.
This narrative of decline and pessimism underlies much of today’s environmental discourse, and is often formulated in a simple fashion: By 2030, we will need two planets to sustain us, owing to higher living standards and population growth. If everyone managed to live at American living standards today, we would need almost five planets.
But this received wisdom is fundamentally wrong.
Environmental campaigners use the so-called “ecological footprint” — how much area each one of us requires from the planet — to make their point. We obviously use cropland, grazing land, forests and fishing grounds to produce our food, fiber and timber, and we need space for our houses, roads and cities. Moreover, we require areas to absorb the waste emitted by our energy use. Translating all these demands into a common unit of physical area gives us an opportunity to compare it with Earth’s productive area — and thus to get a sense of how sustainable we are.
For more than a decade, the World Wildlife Fund and other organizations have performed complicated calculations to determine individual “footprints” on the planet. The WWF points out that we are already living beyond Earth’s means, using around 30 percent too much. And it will get worse. They tell us that the recent financial crisis “pales in comparison to the looming ecological credit crunch,” which could presage “a large-scale ecosystem collapse.”
The message has been received, loud and clear. We are using up too much of the planet’s area. But wait a minute. How can we do that? How can we actually use more area than there is on Earth?
Obviously, any measure that tries to aggregate many different aspects of human behavior will have to simplify the inputs; the ecological footprint is no different. For example, when we talk about American lifestyles needing five planets, we assume that technology is frozen, whereas it is likely that worldwide land-use productivity will increase dramatically. Likewise, organic farming actually leaves a larger footprint than its conventional cousin.
Yet, despite such shortcomings, it is clear that areas we use for roads cannot be used for growing food, and that areas we use to build our houses takes away from forests. This part of the ecological footprint is a convenient measure of our literal footprint on Earth. Here, we live far inside the available area, using some 60 percent of the world’s available space, and this proportion is likely to drop, because the rate at which the Earth’s population is increasing is now slowing, while technological progress continues. So no ecological collapse here.
There is just one factor that keeps increasing: our carbon emissions. It is not at all obvious to anybody how to convert CO2 to area. The WWF and some researchers choose to get around this by defining the area of emissions as the area of forest needed to soak up the extra CO2. This now makes up more than 50 percent of the ecological footprint, and will grow to three-quarters before mid-century.
In essence, we are being told that we ought to cut emissions to zero, and to plant trees to achieve that, meaning that we would have to plant forests today on 30 percent more than all of the available land, and plant forests on almost two planets by 2030. This is unreasonable.
Is it really necessary for us to cut all emissions? Just cutting about half of all emissions would reduce greenhouse gas concentrations in the medium term. More importantly, planting forests is one of the least area-efficient and technology-intensive ways to cut carbon. Solar cells and wind turbines require less than 1 percent of the area of forests to reduce CO2, they become increasingly efficient, and they can often be placed on non-productive land (such as wind turbines at sea and solar panels in deserts). Measured this way, the scary eco-crunch disappears.
Due to technology, the individual demand on the planet has already dropped 35 percent over the past half-decade, and the collective requirement will reach its upper limit before 2020 without any overdraft.
When we really examine the “ecological footprint” calculations, we discover that the only thing the world is running out of is space to plant a colossal amount of imaginary forest that we wouldn’t have planted anyway, to avoid CO2 emissions that we can prevent through much smarter and cheaper means.
That our profligate consumption requires five planets is a catchy story, but it is wrong. The planet we have is more than enough.
Bjorn Lomborg is author of “Cool It: The Skeptical Environmentalist’s Guide to Global Warming.”
