Action on global warming? No new science required..

Power Struggle
by Bradford Plumer
Do we need a technological breakthrough to avert the climate crisis?

A substantial body of evidence suggests that the world can make huge emission cuts in the next few decades without needing to wait for grandiose new technologies to arrive. In 2004, two Princeton scientists, Stephen Pacala and Robert Socolow, published a much-discussed paper in Science laying out 15 carbon-cutting strategies that have already been field-tested, which they dubbed "wedges." Solar power constituted one wedge, nuclear another, stricter fuel-economy standards for cars a third, reversing deforestation a fourth, and so on. The world, Pacala and Socolow showed, could cut emissions dramatically and still satisfy growing energy demand by deploying just seven of those wedges on a grand scale. (That's no mean task: One "wedge" of nuclear power, say, would mean building 21 new plants each year between now and 2050.) While some experts now believe we need even more wedges to meet the ipcc targets, several research efforts have reached similar conclusions: By combining everything we now have on hand, we can tackle a sizeable chunk of the problem at a reasonable cost. A 2008 McKinsey Global Institute analysis pegged the investments needed by 2030 at around 0.6 to 1.4 percent of global GDP and noted that the impact on the world's economic growth rate would be minimal, "even with currently known technologies."

The IPCC lists a wide array of technologies either available now or very likely to surface in the near future that could help reduce emissions. The former category includes (among other things) nuclear power, hydropower, wind power, geothermal, fuel-efficient vehicles, hybrids, biofuels, public transit, reforestation, and landfill methane recovery. The list of just-around-the- corner strategies includes carbon sequestration for coal-fired plants, advanced nuclear plants, tidal and wave power, cellulosic biofuels, and advanced electric vehicles. While no single solution will make more than a modest dent in the world's emissions--none of those items has the vast potential of, say, artificial photosynthesis--when combined together, they should steadily chip away at carbon emissions.

One particularly promising example is solar thermal power, in which large arrays of mirrors heat a liquid that can either generate electricity or be stored for when it's cloudy or dark. Such plants are being built now, and, if Congress passed a carbon price that made them more competitive with coal and natural-gas plants, they'd become even more prevalent and the price would continue nudging downward: The National Renewable Energy Laboratory has already estimated that these plants will be able to compete with existing natural-gas plants by 2015, and solar-power expert Ken Zweibel has estimated that they could, in theory, supply up to 69 percent of America's electricity by 2050. It would require a fair amount of government support and infrastructure investments, as well as further R&D, but not a whole new level of science. In the short term, meanwhile, one of the biggest reductions in emissions will come from making buildings and homes more energy-efficient, which typically requires no fancy new technology at all--just smarter regulations.

It's true that, eventually, existing technologies will hit a wall. If electric cars powered by lithium-ion batteries become widespread, for instance, then world lithium supplies could conceivably dwindle. Or, at a certain point, the need for cost-effective electrical-power storage could become a serious issue. (Right now, Denmark gets nearly 20 percent of its electricity from wind, but can only "store" that power by exporting the excess to Sweden and Norway, which send back hydropower when the wind isn't blowing-- a clever workaround that will prove less feasible as renewables spread.) "There are a bunch of things we know how to do now, and we want to use all the incentives we can to get those things out there," says Argonne's George Crabtree. "But, eventually, their impact will saturate, as soon as they're fully deployed--and that's where you'll need serious innovation."

By mid-century or so, we really may need the sorts of artificial leaves and futuristic batteries we can barely begin to imagine right now. And it is far less outlandish to expect that, by that time, science will be able to deliver such breakthroughs. But all of those sci-fi technologies decades from now won't mean much if we've long since blown past our carbon budget. That means doing as much as we can now--and fast.



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