Tag Archives: decoupling

What’s new with “decoupling”?

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Decoupling is the idea that environmental impact per unit of economic growth is declining. If it were to decline fast enough, in theory, it would be possible for growth the continue indefinitely at the same time absolute impact is declining. This article tries to measure the rate this may or may not be happening, and concludes the long term trend is not even close to being on a path where we could turn the corner and see absolute impact stabilize, let alone decline.

While globally, CO2 emissions per unit of GDP are declining, the decoupling rate from 1995 to 2018 was only -1.8 percent annually. To achieve net zero by 2050, the rate would have to accelerate to -8.7 percent, assuming population and GDP growth projections as given, or by a factor of almost five.

Bruegel.org

This seems about right to me. The idea that we need to choose between “growth” and sustainability in the long term, of course, is logically flawed. If impacts continue to grow, there will come a point where the system breaks and human welfare is no longer able to increase.

There are a few flaws in the decoupling argument. “Growth”, as usually measured by GDP, is a measure of gross economic activity, which includes both benefits and costs to humanity. So in comparing impacts (costs) to GDP (sum of benefits and costs), you have an equation with too many unknowns, unless you can come up with some agreed-upon reasonable measure of costs. If you can do that, you would simply subtract costs from benefits to get net benefits, and figure out whether those are growing or not. They may or may not be growing right now. Even if they are, you need to consider whether they can continue to grow in the future, or whether the underlying system is eventually going to break and no longer be able to support further growth. You also need to consider risks of really bad things happening, as well as the odds of really good things like major technological breakthroughs happening. I would also point out that at the moment we are using carbon emissions as a proxy for sustainability more generally, but there is a lot more that should be considered in a holistic view of a sustainable long-term human-planet system.

More from Less by Andrew McAfee

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More from Less: The Surprising Story of How We Learned to Prosper Using Fewer Resources―and What Happens Next is a new(ish) entry in the decoupling/dematerialization debate. The argument is that we (i.e. the United States) are gradually using fewer natural resources and producing less pollution each year while still growing our economy and quality of life.

This is the point in the post where I have to admit I am reviewing a book I haven’t read. I read the description of the book on Amazon, and this review in Foreign Policy. I would imagine that an MIT scientist (the author, Andrew McAfee) would get the math right. I would imagine he probably understands the difference between stocks and flows. But the general public, and even well- but narrowly educated people typically do not. First we have to decrease the rate at which our footprint is growing, which it sounds like this book might make a case that we have. That is good. But our footprint is still too big to sustain our way of life indefinitely, and still growing. Second, we have to start shrinking our footprint. I don’t think we have, and I am not sure this book makes that case. It is still too big to sustain our way of life indefinitely. Third, we have to shrink it to a level that can sustain our way of life indefinitely. We have to complete these three steps in order, and complete them all before it is too late to save our civilization and our planet’s ecosystems in roughly their current state. It’s unfair because I am literally judging the book by its cover, but it sounds like it makes a case that we might have completed only the first step.

The Foreign Policy article argues that it doesn’t even make that compelling case because it ignores trade and external impacts. In other words, the environmental impact of our domestic consumption and economic activities is happening in developing countries, plus the oceans and atmosphere. It’s surprising to me if he made that obvious a mistake, but again, I would have to read the book to find out. It is unlikely my employer and family and need for some minimal amount of physical rest will afford me an opportunity to do that soon. So if you read it, let me know what you find out!