The terawatt challenge
This brought a smile to my face. Here’s the beginning of an intro into a recent Science paper on climate change:
Slowing climate change requires overcoming inertia in political, technological, and geophysical systems. Of these, only geophysical warming commitment has been quantified.
It’s true. How do you quantify the degree of political inertia around climate change? It seems endless. The authors of the paper, led by Stanford University doctoral student Steven Davis, go on to explain different scenarios of energy production and their impacts on global warming.
They start with an interesting proposition. If we just age out all our existing CO2 spewing infrastructure — all the coal-burning power plants, motor vehicles, etc. — we’d limit atmosphere concentrations of CO2 to 430 ppm, and mean warming to about 1.3 degrees C. We’ll call this the “Cuban Revolution model” of mitigating global warming, after the 1959 uprising that essentially froze the Caribbean island in time with no new cars and taped-up infrastructure.
Of course that’s never going to happen. But the scenario serves a point when we talk about as-is scenarios that bring us to 500 ppm CO2. The sources of the most threatening emissions have yet to be built, the authors explain. So the question becomes, what is the threat of climate change from existing devices relative to those that have yet to be built? What are the sources of “infrastructural inertia” in our economies?
Take fossil fuel combustion, as a major example. Burning fossil fuels in an as-is scenario from 2010 to 2060 would result in a rise to 430 ppm CO2, and a temperature increase of 1.2 degrees C. By comparison, expanding the fossil fuel infrastructure at a rate predicted by the IPCC report would result in a CO2 concentration of 600 ppm, and a temperature rise of 2.4 to 2.6 degrees C.
(As an important aside, climate stabilization benchmarks have us aiming toward 450 ppm and 2 degrees C rise).
What this brings you to is nothing revolutionary. The world needs to deploy technology to meet increasing energy demand that emits less CO2. The new power we produce needs to come from these kinds of technologies. It’s a tall order, considering that China has been building two new coal-fired power plants, per week.
“…satisfying growing demand for energy without producing CO2 emissions will require extraordinary development and deployment of carbon-free sources of energy,” the authors write. They estimate that carbon-free sources will need to cover us for about 30 terawatts (TW) by 2050. The world’s current total energy consumption is 12 TW.
This new energy stream has been called the “terawatt challenge,” by the late Nobel Laureate Richard Smalley, who called for a “new oil” that will be the basis for energy prosperity in this century. We have a long way to go. Most renewable energy models foresee contributions of just a couple TW, a fraction of what’s needed to power the globe.