There are two main strategies involved in tackling climate change. First, we could try to slow or stop the pace of global warming by curbing our greenhouse-gas emissions. And second, there's adaptation — we can try to revamp our existing infrastructure to protect ourselves against some of the effects of a warmer planet.

That should do the trick. (Washington Post)

Many experts say we'll need to do both. Even if the world could zero out its emissions tomorrow, scientists have found, we've already loaded enough carbon-dioxide into the atmosphere to raise global temperatures by about 1.4°C over pre-industrial levels.* That's less drastic than what will happen if we keep burning fossil fuels at our current pace, but even a mild temperature increase will likely mean more heat waves, droughts, sea-level rise. A certain level of adaptation will be necessary no matter what we do about emissions.

And the fallout from Hurricane Sandy has provoked some politicians into taking adaptation more seriously — even if it's hard to link a single hurricane to climate change. "These are extreme weather patterns. The frequency has been increasing. It is something we’re going to have to start thinking about,” said New York Gov. Andrew Cuomo after surveying the flooding in lower Manhattan. "The construction of this city did not anticipate these kinds of situations. We are only a few feet above sea level."

So how far along is the United States in thinking about climate adaptation? Not very far at all. A new comprehensive survey from October 2012 finds that some states and cities around the country are beginning to draw up plans, but they're nowhere near adequate. "Most adaptation actions to date appear to be incremental changes," the survey notes, "not the transformational changes that may be needed in certain cases to adapt to significant changes in climate."

Climate-change adaptation can take a variety of forms. Louisiana has written up a plan to restore and protect its coastline from further erosion at the hands of sea-level rise over the next 50 years. Texas is trying to improve its drought-response plans. Governors out West have begun talks on how global warming might affect water allocation in the Colorado River. New York City has to think about how to deal with fiercer storm surges in the years ahead as ice sheets melt and sea levels rise.

But the adaptation survey, led by Rosina Bierbaum of the University of Michigan, found that many of these plans were hobbled by poor funding and various legal impediments. Another problem is that climate models still aren't as adept at predicting precise impacts in small areas, which makes preparation difficult in some cases. (It's easier for climatologists to forecast that droughts in North America will become more severe and persistent than to predict exactly where they'll take hold.)

What's more, the survey notes, there are surprisingly few studies looking at the cost-effectiveness of various adaptation strategies. As John Carney points out over at CNBC, New York City isn't going to be able to harden its infrastructure against every single natural disaster ever. Some actions just won't be worth the price tag. (It wouldn't be terribly cost-effective to move all of Manhattan further inland, for instance.) The same is true for all regions. So a lot more work needs to be done to figure out what, exactly, cities and states can do to become more resilient against various climate impacts.

As Mireya Navarro reported in September in the New York Times, that's something that New York City was beginning to study. After all, as sea levels rise, storm surges and flooding from even small storms will get more severe. One 2009 commission warned that New York's subway system was unprepared for such flooding. Another study recommended movable barriers at places like under the Verrazano-Narrows Bridge or at the upper end of the East River. 

But the process has been fairly slow-going, Navarro explained: "Planning experts say it is hard to muster public support for projects with uncertain or distant benefits."

Adaptation measures may get a more urgent look in New York City now that Hurricane Sandy has seized everyone's attention. But plenty of other cities and states are also moving at a sluggish pace in planning for climate-related threats. And, in some areas, the federal government has been encouraging construction on coastal property that's most at risk from sea-level rise. Adaptation only tends to garner attention after a big disaster. But it's often cheaper to act long before then.


* A quick explanation for that 1.4°C number. The planet has already warmed about 0.8°C on the surface over the past century. But we haven't yet seen the full warming effects from all the carbon dioxide we've put in the air — there's typically a delay of a few decades thanks to the thermal inertia of the oceans. According to a 2005 study in Science, there's already an additional 0.6°C or so of warming in the pipeline, no matter what else we do. And, of course, if we keep emitting greenhouse gases, temperatures will go up even further. 

Further reading:

— Why Hurricane Sandy should get us thinking more about climate-related disasters

— How the United States is preparing for sea-level rise. (We're not, for the most part.)

— What we know about climate change's effects on drought and wildfires

— And, actually, there's technically a third strategy for dealing with global warming: geoengineering to cool down the planet. But most scientists agree that this is still risky and unproven.