Climate change optimism for Earth Day

It's Earth Day, so in the spirit of celebration, instead of dwelling on the bad news (like the report that 9 out of 10 attendees at the recent Copenhagen scientific conference on climate change don't expect us to be able to avoid increasing the planet's average temperature by a "dangerous" 2°C -- I said I wouldn't dwell, but I reserve the right to mention), let's consider things from an optimist's point of view.

Which optimist should we choose? How about New York Times columnist John Tierney? Not because he's a particularly well-regarded climatologist. He's not even a scientist at all. Like me, he thought about going down the science road, but decided that communications was more his thing. Unlike me, however, he remains extraordinarily upbeat about the human species' ability to ensure everything works out just fine, thanks to technology. His latest column is typical.

In that column he makes two predictions:

1. There will be no green revolution in energy or anything else. No leader or law or treaty will radically change the energy sources for people and industries in the United States or other countries. No recession or depression will make a lasting change in consumers' passions to use energy, make money and buy new technology -- and that, believe it or not, is good news, because...

2. The richer everyone gets, the greener the planet will be in the long run.

His reasoning has a lot to do with the supposed trend toward decarbonization that comes with increasing levels of prosperity. Just as we in the Western world went from wood to coal to oil to nuclear, reducing our carbon emissions at each step, so will the still developing nations. Eventually we'll be green by default. Because that's the way things work.

Tierney cites of the work of Rockefeller University's Jesse Ausubel, who directs the Program for the Human Environment:

"The long-term trend is toward natural gas and nuclear power, or conceivably solar power. If the energy system is left to its own devices, most of the carbon will be out of it by 2060 or 2070."

This trend, says Ausubel, has been at work since 1850 and there's no reason it should stop now. If he's right, then that is good news. Let those infallible market forces just do their thing and we'll manage to avoid a good portion of the global warming that our fossil fuel emissions are causing.

I have no reason to doubt that Ausubel, and Tierney (although Joe Romm calls him "easily the worst science writer at any major media outlet in the country" for uncritically quoting propaganda for the Competitive Enterprise Institute among other missteps) are right. In the long run, anyway. Sooner or later, even China will stop building coal-fired power plants because they're just plain nasty and clean alternatives make more sense.

That's my optimism for the day.

Now, and I promise I won't dwell on it, I feel compelled to add a little dose of doubt. Tierney and Ausubel may be right in the long run, but that doesn't mean we should stop worrying and learn to love the free market's solution to climate change. What about the precise details of the trend they're predicting?

First of all, note the schedule Ausubel provides. "Most" of the decarbonization will be complete by 2060 or 2070. What exactly does he mean by "most"? Will that be soon enough? Most climatologists I've come across estimate that we need to be more or less carbon neutral by 2050 to avoid straying into the risky territory associated with tipping points that could set off the really inconvenient warming. Calls for an 80% cut by 2020 might be a bit on the overly cautious and ambitious side (see the Earth Policy Institute's plan), but depending on the shape of the decarbonization curve, waiting until 2060 or 2070 to reach 80 or 90% reductions doesn't exactly eliminate serious risk.

Indeed, the shape of that curve is critical. Are we talking about a linear reduction, in which we reach 50 percent cuts around 2030 or 2035? If so, that might be good. But like climate itself, the adoption of technology is rarely a linear process. More like a gradual growth in the early stages, building to a critical threshold after which it accelerates rapidly. It takes time to build power plants, for one thing, meaning little change until they all come online. For CO2 reductions that means most of the reductions could be experienced in the final decade or so, which in turn means that by 2050 we could still be emitting significant amounts of greenhouse gases.

We might end up decarbonized just a few years too late. Tierney's optimism will have been well-founded, but moot. The thermal inertia associated with anthropogenic global warming isn't going to make allowances for any "natural" evolution in technology.

Again, Tierney could be right in a general way but tragically wrong on the specific. That decarbonization curve he's counting on isn't and won't be monotonic. There are dips and bumps along the way, too. Just when, exactly, will China and India stop building more coal-fired plants? If nuclear is a next step, how do we ensure developing countries can afford to build what is now in the western world the most expensive way to produce energy of all the non-renewable alternatives?

I'd be a lot more comfortable if we had wider margins of error to allow decarbonization to express itself fully in time. As it is, there's not a lot of room for unanticipated variables or even anticipated ones. And another thing: just because things have always worked in one manner, that's no reason to assume they will continue to do so.

But hey, at least we have some theoretical optimism to get us through the day.