If we are going to cut carbon emissions by 90 percent from their levels in the 1990s, we’re going to have to make a lot more clean energy than you think.

Question: What is the scale of the energy challenge? 

Nate Lewis: What distinguishes energy from most other technologies is the sheer, imposing scale of energy demand. Right now we use energy at an average rate of 14 trillion watts. That rate is going to double almost all projections, say, within our lifetimes to something like 25 trillion watts. Even if we save as much energy as all the energy we use now combined, you still have to make as much clean energy as all the oil, coal, gas, and nuclear power on our planet combined within our lifetimes, if we are really going to think about cutting carbon emissions as carbon dioxide by 80% or 90% from their 1990 levels. 

Question: How is it possible to save as much energy as you're talking about? 

Nate Lewis: Energy efficiency is something that we, as individuals, can absolutely do now. It’s not like trying to vote or influence public utilities commissioners to buy wind energy for your municipality. We can, as individuals, make choices about what mileage cars we buy, about substituting a light car for a heavy car, about weatherization, about insulation, about retrofits in buildings, and in our homes where all studies show that one could save 70 percent of the energy now consumed in an average home by using best practices on insulation, on dual paned windows, on good attic insulation, on heating, ventilating air conditioning systems, and things like that. So, we should be doing those things because if we don’t save energy, like our lives depended on it, we make a difficult problem nearly impossible. 

Question: Is it a matter of behavioral shifts, or technological shifts? 

Nate Lewis: We can probably save most of this energy with just technological shifts. Now, this is something that many people don’t necessarily get their grips around mentally that saving energy doesn’t mean taking the bus all the time and giving up my car. It doesn’t necessarily mean downsizing my home or getting rid of my swimming pool heater. It does mean being smart about how we use our precious energy sources. It means insulating our homes better so we use less energy. It means more passive solar heating and lighting so we don’t have to turn on that furnace or turn on as many light bulbs. It means getting light emitting diode (LED lights) instead of incandescent lights. Almost all of these things, after the initial capital investment, actually save people money as well as saving them energy. It’s just that we have to get in the mentality of thinking a little bit more in the long-term as opposed to the short-term. “I can’t afford that light bulb because it’s $4.00 and the incandescent one is 50 cents,” even though over the life of the bulb, it’s smarter to buy the more expensive compact fluorescent or LED bulb than it is to buy the cheaper one upfront. 

Question: What about coal use? 

Nate Lewis: So there’s no question that coal is where the rubber meets the road in energy policy. First, coal is the cheapest source of electrical power in most regions of the world. Especially in places like China where they put on last year a mind-boggling 2 Gigawatts of coal-fired electric power a week, every week for an entire year. On the other hand, there are things we can do about that. 

One, in the short-term, we could decide to pay a little bit more for our electrical power and then instead take that money and use renewable energy. We could actually first save energy so we don’t have to build any new coal-fired power plants to meet demand. We could build more nuclear power plants; we have many options. We just have to get into the mentality that we value our atmosphere. There’s a price to be paid for emitting carbon dioxide to it. And when we figure that price in the math, then maybe it’s not always the case that coal is the cheapest long-run way to make power, maybe we value our planet a little bit in the arithmetic too. And if we do that, then you come up with a different calculus.