http://www.palmbeachpost.com/news/most-of-keys-may-be-lost-to-sea-1660865.html

South Florida can't afford to ignore growing dangers from pollution-fueled climate change, according to new findings from the Natural Resources Defense Council.

Rising seas, more flooding from storm surge and saltwater seeping in and fouling drinking water supplies are among the looming threats from climate-altering pollution, according to the environmental group's nationwide review released Tuesday.

South Florida, and Miami in particular, is one of the most vulnerable parts of the country, and local governments need to play a larger role in dealing with the damaging effects of climate change, according to the NRDC.

"Ideological deniers of climate change debate facts, [but] cities don't have that luxury," said Dan Lashoff, director of the NRDC's climate center. "Plan, prepare and act. The sooner the better."

What causes climate change?

Manmade air pollution adds to the carbon dioxide and other greenhouse gases in the Earth's atmosphere that trap heat from the sun.

Increased levels of greenhouse gases are leading to higher temperatures, melting ice sheets and swelling oceans, resulting in rising sea levels.

What are the potential local effects of climate change?

The South Florida Water Management District estimates that sea levels could climb 5 to 20 inches during the next 50 years.

The NRDC report warns of a larger sea level threat for Miami - a 1.5- to 2.3-foot sea-level increase by 2050 and 3 to 5 feet by 2100.

The projections are more severe for the Florida Keys, which could lose more than 90 percent of land area to rising seas by 2100.

Across the region, water managers already have identified 28 flood-control structures along the southeast coast and six along the west coast at risk of not working properly because of rising sea levels.

What is being done locally to address climate change?

Palm Beach, Broward, Miami-Dade and Monroe counties have formed the Southeast Florida Regional Climate Change Compact to find ways to reduce pollution and adapt to the changes that climate change brings. The county leaders are working with university scientists to try to reach consensus on regional sea level-rise projections to help plan for how to deal with rising water.

The South Florida Water Management District is continuing to "evaluate the potential implications of sea level rise," according to a statement released Tuesday in response to the NRDC report

What are hurdles to addressing climate change?

Cost remains a hurdle.

Developing alternative energies to fossil fuels, improving coastal flood-control structures and relocating other infrastructure that could be inundated by rising seas - such as roads, water plants and even nuclear plants - all comes with steep costs.

"Consider the costs of not acting," said Michelle Mehta, the lead author for the NRDC climate change report.