2018/03/26: the more we grow, the more we eat away at the web of life on which we all depend.
We have known about this problem for decades now, but we've been told not to worry: As technology improves and becomes more efficient, we'll be able to keep growing the economy while nonetheless reducing our impact on the natural world. The technical term for this is "green growth," which requires absolute decoupling of GDP from material use. According to the theory, we can speed this process along by incentivizing innovation; if we tax carbon emissions and material extraction, we can spur companies to invest in more efficient tech.
Here's the magic number: 50 billion tons. That's how much of the Earth's materials and life forms we can safely use each year. That includes everything from wood to plastic, fish to livestock, minerals to metals: all the physical stuff that we consume. Right now, we're using about 80 billion tons each year-way over the limit. So for growth to be green, we need to somehow get back down to 50 billion tons despite expanding the GDP.
When green growth theory was first proposed, there was no evidence on whether it would actually work-it was purely speculative. But over the past few years, three major studies have set out to examine this question. All have arrived at the same rather troubling conclusion: Even under best-case scenario conditions, absolute decoupling of GDP growth from material use is not possible on a global scale.
Why the bad news? The main reason is that tech innovation just doesn't work the way most of us assume. We know that Moore's law says that chip performance doubles about every two years-but this doesn't apply to material use. There are physical limits to material efficiency, and once we start to reach them then the scale effect of growth drives material use back up in the long run. For instance you might be able to produce a wooden table more efficiently, but you can't produce a table out of nothing. In the end you'll need a minimum amount of wood, and once you reach that limit, then any growth in table production is going to come along with a corresponding growth in wood use.
It would be hard to overstate the impact of these results. Right now, our only plan for dealing with the ecological emergency that's staring us in the face is to hope that tech innovation and green growth will mitigate the coming disaster. Yes, we're going to need all the wizardry we can get-but that alone is not going to be enough. The only real option is in fact much simpler and more obvious: We need to start consuming less.