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Report:  Climate Change Already Underway in US


With international climate talks under way in Bali, Indonesia, [12/3-14] the non-profit Pew Center on Global Climate Change released a report examining the impact climate change is having on different regions of the United States. The study argues that federal, state and local decision-makers must work both to mitigate global warming and to adapt to its consequences.

The report looks at specific impacts of climate change in four regions of the United States. It finds that Midwestern heat waves and Western wildfires are both likely to become larger, more frequent and more intense as the result of climate change.

"Gulf Coast wetland loss and Chesapeake 'dead zones' are likely to be exacerbated by climate change making them more difficult to restore," adds Pew Center for Global Climate Change president Eileen Claussen.

The case studies consider how non-climate factors like population growth, development, and land management interact with the problems of a warming planet. For example, along Louisiana's Gulf of Mexico coastline, wetlands play an important role in the quality of life, helping to sustain the U.S. economy and protecting people and property from the dangers of storm surges.

Continued coastal development coupled with the anticipated rise in sea levels could drown the wetlands according to report co-author Robert Twilley, professor in the Department of Oceanography and Coastal Science at Louisiana State University.

"The significance of this is that under storm events such as hurricanes, these open waters increase the risk of coastal communities to flooding events and coastal hazards," Twilley says.

The Gulf Coast is also critical to domestic oil production. Twilley says what happens to the wetlands directly affects offshore industry and land-based operations in the region.

"Some of the companies that are forward-thinking about this risk see where corporate sustainability is co-dependent on environmental sustainability," he says. "They see the investments in our restoration program as investments in their industry as well."

Looking at evidence of climate change in the American west, the report notes that over the past decade, earlier spring snowmelt and hotter, drier summers have led to more wildfires. Report co-author Dominique Bachelet who directs Climate Change Science at the Nature Conservancy, says the "deadly combination of human behavior and climate change has created a scenario where we will likely see more severe wildfires like the ones we've seen in 2007."

Carbon dioxide, a greenhouse gas, also promotes tree growth. But that may cause problems, unless the growth is managed properly to lessen fire risk.

Bachelet says the situation is made worse when the forest ecosystem is fragmented by roads and buildings.

"When you build roads, the roads open up a way through the forest to bring warm, dry air, and that may dry up the surrounding under story near the roads," she says. "And that makes the forests more vulnerable to fire."

The report also focuses on the Chesapeake Bay, on America's mid-Atlantic coast. The Chesapeake Bay is the largest and most productive estuary in North America. Agricultural runoff, largely from farms, but from cities too, has led to hypoxia, or an inadequate level of oxygen in the coastal waters. That's created dead zones, which affect fisheries and recreation in the region.

Report Co-author Donald Boesch, University of Maryland professor of marine science and President of the University of Maryland Center for Environmental Science, says climate change will exacerbate the situation.

"Many of the anticipated changes, for example increased spring flow during the spring and winter, warmer temperatures, calmer summer winds, and increasing [coastal water] depth due to sea level rise would move the ecosystem in the directon of worsening hypoxia," he says.

A growing number of scientific studies document these kinds of changes, according to the Pew Center on Climate Change. President Eileen Claussen wants decision makers who read the report to understand that while climate change is a global problem, its effects are felt locally.

"Every planner, every developer, every policy maker, will have to factor climate change into the equation, beginning now," she says.

Claussen says getting the right policies in place now is essential to reducing the risk from current and future climate-change impacts.

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