Time to begin 'adapting' to climate change?

At the World Bank in Washington, officials have posted some new "help wanted" signs. The bank is looking for a few good specialists (two, to be precise) to focus on adapting to global warming.

It's a small beginning, perhaps. Still, the ads represent one signal that adaptation is emerging from the political doghouse to take its place among the front-rank options for dealing with climate change.

At least in the developed world, the idea that people should start figuring out how to deal with the projected effects of warming – changing temperature and rainfall, shifts in growing seasons, more bouts of severe weather, and rising sea levels – has been overshadowed by calls to reduce carbon-dioxide emissions. Some environmentalists have viewed adaptation either as a white flag on the issue or as a refuge of contrarians who pooh-pooh the broad consensus that human activity is warming the climate.

But last week's release of a report on the science of global warming – with its projections of warming based on emissions already in the air, as well as on potential future emissions trends – has helped underscore the need. "Climate change is here and now," notes Ian Noble, a senior climate-change specialist at the World Bank. "We have to adapt."

In some cases, adaptation can be politically wrenching.

Australia, for example, is facing the worst drought in a century. The drought's length and severity is consistent with some projections of global warming, several scientists note. The national government has proposed a controversial, $2.5-billion (Australian) plan to wrest control of the withering Murray-Darling river basin – the country's largest river system – from the four states in eastern Australia that draw water from it. Meanwhile, Queensland has adopted regulations that since last March have required each new home in the state to draw nearly 40 percent less water than pre-2006 homes. In some towns, building codes specify the installation of large holding tanks to capture and store rain for use in gardens and to flush toilets.

If Australia represents the dry end of the adaptation spectrum in the developed world, New Orleans and the Gulf Coast may well represent the wet end. The region is still struggling to recover from hurricanes Katrina and Rita in 2005. The tragedy surrounding those two storms underline just how maladapted major population centers in the region are to today's conditions, let alone those that might hold in 2050 or 2100, experts say.

The latest draft of Louisiana's master plan for a "sustainable coast" contains several provisions, which are a direct response to the prospects for rising sea levels, increased hurricane intensity, and other effects of global warming, notes Jonathan Porthouse, executive director of the interagency planning team.

In the group's view, coastal Louisiana will be one of the first regions to feel global warming's imprint. Ironically, the potential for reductions in freshwater supplies in the western part of the state – already facing a water-management challenge – may grow, Mr. Porthouse says. The Mississippi River drains water and sediment from 40 percent of the US, he notes. Changes in flow upstream could have a serious effect on efforts to restore Louisiana's wetlands as well as on the fresh water available to the state.

One element that should help guide the region's adaptation measures is a hydrology model developed over the past two years at the University of Louisiana at Lafayette. "We're at the point now where we can play what-if games in the virtual world to see what would be effective ... it's now starting to bear fruit," he says.

"The reality is that we should be adapting" and tackling carbon-dioxide emissions at the same time, notes Roger Pielke Jr., a science-policy specialist at the University of Colorado at Boulder.

As early as 1992, he says, the US National Academy of Science recognized that adaptation needed to play a key role in humanity's response to global warming.

Some analysts argue that demoting adaptation efforts to the status of "poorer cousin" to emissions reductions in the public debate has cost precious time.

"We've known for 100 years that if you pump enough CO2 into the atmosphere, you're going to get global warming," says Daniel Sarewitz, a science-policy specialist at Arizona State University in Tempe. Despite the conviction that humans are warming the climate expressed in the report from the Intergovernmental Panel on Climate Change, specific aspects of the science remain riddled with uncertainties. This holds especially true for models trying to project regional effects, he says.

"We spend all this effort trying to understand climate dynamics, but the major variables are the interactions within society and between society and climate," he says, referring to everything from populations exploding along vulnerable coastlines to decisions about what types of crops to plant.

For example, Dr. Noble notes that in the Indian state of Andhra Pradesh, efforts to encourage growers to replace groundwater- gulping rice with grains that grow better in a drier climate are hitting a wall. "Farmers know that they'd be better off growing millet or sorghum," he says. "But there's no market for millet. If they have to live on what they produce, they'd rather produce rice than millet."

And while some of the highest-profile adaptation challenges may come from severe weather events, Noble adds that "ordinary" weather events can still pose enormous hardship, particularly in the developing world.

If "normal" rain comes in less-frequent but more-intense storms, one storm "could wash away half your crop. That doesn't qualify as a disaster, so you don't get disaster relief," Noble says. In that case, adaptation measures could range from runoff control efforts to government policies establishing crop insurance where it doesn't exist now. It also means building roads and bridges far more resilient in the face of flooding.

Ironically, many measures needed to adapt to global warming come from the same toolkit disaster planners and development agencies use today. "Adaptation means doing the things you do now, but doing them much better," he says.