The Next Emissions Story

If you’ve been following the emissions story the past few years, you will know that slower economic activity and the rise of renewables have started to seriously blunt the growth of global carbon. In the OECD, for example, CO2 output has surely peaked, with virtually no risk whatsoever that developed nations will return to the carbon output highs of last decade. Globally, emissions growth started to stall out 2-3 years ago. Because, even in the Non-OECD, China has begun to thwart marginal growth of fossil fuel consumption through a revolutionary buildout of wind and solar power. (see: Are We Finally Seeing Good Climate News from the US and China?)

The next emissions story therefore will not be about the growth of CO2, but rather, the difficulty in engineering a new phase of carbon output decline. Like the cyclist behind a belching bus (photo above), an encouraging adoption phase globally of wind, solar, energy efficiency, walkable urban space—and yes, cycling—is now running up against legacy, fossil fuel systems. If you are a climate scientist, the risk is now shifting, therefore, from the next phase of carbon growth to a long standoff between marginal growth from clean sources and fossil fuel dependency.

A better conversation about these risks can benefit, therefore, from a delineation between adoption and dependency. All too often, fluctuations in energy usage in dependent systems are mis-read as growth (or adoption). Oil use in the United States is a perfect example. Let me explain.

The adoption phase of oil—the uninterrupted sequence of years in which the economy required ever higher volumes of oil to grow GDP—ended roughly 40 years ago in the United States. Oil consumption last year, of 35.89 quadrillion btu, was first reached 40 years ago when, in 1976, US oil consumption crossed above 35 quadrillion btu for the first time. In the last 40 years, the US population has grown from roughly 220 million to 330 million people. GDP (nominal) has grown roughly 10X, from 1,877 T to 18,567 T. Ergo, oil use per capita, and, per unit of economic growth, has been in steady decline for four decades.

But a new phase began in US oil consumption starting four decades ago: the dependency phase. Understanding this dependency phase is crucial to a broader framework-understanding of where we are today in global coal dependency, oil dependency, and natural gas dependency.

Consider, for example, the chronic discussion of peak car. Animated by data points on per capita auto ownership, miles driven, and gasoline consumption in the United States, the conversation appears to be teetering always to a question of whether the next new growth phase is coming in the American automobile complex. But growth in the US automobile complex is largely off the table. Dependency, and the failure of the US to invest more aggressively in public transport (like the rest of the world) is the real question, the real problem.

The qualities of the peak car discussion can be found also in the discussion about peak coal. Because wind and solar are doing so much work now at the margin, and because solar costs are falling so dramatically, the risk of a new increase in global coal consumption has crashed. Coal growth is over, full stop. And yet, many climate models still embed a risk of future coal growth, in part, because we are too close in time to coal’s resurrection (1995-2010) when coal and coal infrastructure was cheaper, and easier to adopt, than renewables. But that era is now behind us as both China, and now India, see that solar is better, cheaper—and most important of all—faster. (see: India Will Crush You with Solar, 13 February TerraJoule.us newsletter).

The probability is high, very high, that global emissions have now peaked. Indeed, if the world puts together a few more years of flat emissions, there will be a temptation to declare an initial, first-goal victory. And that’s fine. The next goal in global emissions—covering 100% of marginal energy consumption growth, while at the same time getting to work on existing fossil fuel dependency—will be harder, or perhaps more pointedly, slower to achieve.

–Gregor Macdonald

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