The “limits to growth” question is receiving a lot of attention this week. On Monday, the Wall Street Journal had a front-page feature length story (“New Limits to Growth Revive Malthusian Fears”) that looked at a number of possible resource constraints, including water and food.
Today, Andrew Revkin of the New York Times writes in his blog (Dot Planet) about an eye-opening presentation made by Dr. Daniel G. Nocera at the first Aspen Environment Forum this week in Colorado. A professor of energy at the Massachusetts Institute of Technology, Dr. Nocera talked about the energy choices we face, if we don’t develop far more efficient solar technologies.
As Revkin reports:
Dr. Nocera said human activities, in energy terms, right now are essentially a “12.8 trillion watt light bulb.” Our energy thirst will probably be 30 trillion watts, or 30 terrawatts, by 2050 with the human population heading toward 9 billion.
If that energy is supplied with coal and oil, an overheated planet is almost assured, he said. Finding other options is a huge challenge, he added. To illustrate, he provided one hypothetical (and impossible) menu for getting those 18 additional terawatts without emissions from coal and oil:
- Cut down every plant on Earth and make it into a fuel. You get 7 terawatts, but you need 30. And you don’t eat.
- Build nuclear plants. Around 8 terawatts could be gotten from nuclear power if you built a new billion-watt plant every 1.6 days until 2050.
- Take all the wind energy available close to Earth’s surface and you get 2 terawatts.
- You get 1 more terawatt if you dam every other river on the planet and reach 30.
As he summed up, “So no more eating, nuclear power plants all over, dead birds everywhere, and I dam every other river and I just eke out what you’ll need in 40 years.”
Revkin blog post is entitled, “All Energy Roads Lead to the Sun.” If so, let’s hope that there aren’t too many bumps, detours and tolls on all those roads.
