President Obama travels to the Everglades on Wednesday to mark Earth Day in a place that showcases the delicate dance between water, land and survival.
In the Everglades, after all, a rise of just a few inches in the level of water or land can make the difference between a cypress swamp and a hardwood hammock, and all the plant and animal life they support.
Little wonder, then, Obama picked this special place to highlight the growing dangers of climate change, the mounting peril it poses and the urgent need to cut the dangerous carbon pollution that's driving this widening scourge.
Like most of Florida itself, the Everglades lies low and flat. Averaging about three feet above sea level, it's largely enveloped by rising ocean. Nearly the size of Connecticut, it slopes gently downward toward the sea from freshwater inland rivers and lakes fed by heavy seasonal rains.
Known for the shallow and slow-moving waters seeping through vast open prairies of saw grass, the Everglades actually hosts nine distinct habitats, from hardwood stands of live oaks and mahogany to forests of slash pines and palmetto palms; from coastal lowlands, marshes and mangroves to estuaries rimming the shores of the Gulf of Mexico and Florida Bay.
Famously home to exotic orchids, pink flamingos, alligators and the endangered Florida panther, the Everglades also feeds essential nutrients to the coastal waters and mud banks, shallow sea grass flats and the pink shrimp, lobsters and bonefish that thrive in those fertile waters.
And the Everglades is the primary source of fresh water for the porous limestone that forms the great Biscayne Aquifer that provides drinking water to some 7 million people.
All of that is in the crosshairs of rising seas, saltwater intrusion, drought, extreme heat and more unless we act now to curb the worst impacts of climate change.
At risk is not only the Everglades, a haven for anglers and the largest American wilderness area east of the Rocky Mountains, but also Florida's diverse economy, more than $200 billion worth of coastal real estate, and the drinking water for one in every three Floridians.
Early warnings have already appeared.
Sea level in South Florida has risen about 10 inches since 1930, as warmer temperatures, globally, melt glaciers and other land-based sheets of ice that add water to the world's oceans.
Average global land and sea temperatures have risen about 1.4 degrees Fahrenheit since record keeping began in 1880 - and the mercury continues to rise. Globally, 2014 was the hottest year on record. The first quarter of this year was the hottest ever. And the 16 hottest years ever recorded have all occurred since 1997.
In the Everglades, rising seas have transformed freshwater lakes and marshland into saltwater flats along parts of Cape Sable. High tides and storm surge tear at the roots of mangroves, speeding coastal land loss. As sea level rises, tidal flows reach further up natural creeks and canals, where salt water erodes the banks and leeches away nutrients from the mud, marl and peat that support oysters and great flocks of wading birds.
In parts of the Everglades, scientists have begun to notice higher water levels inland, a sign that rising seas could be forcing saltwater into the porous limestone and pushing back on fresh water inside, as rising temperatures increase surface evaporation and freshwater use.
Most scientists believe global sea level will rise by as much as another two feet by the end of this century, and very possibly more.
That would mean disaster for the Everglades, much of which would be submerged in saltwater, killing off plants, driving off animals and contaminating fresh water above and below ground.
We can stop the worst from happening if we take action now to reduce the carbon pollution produced when we burn coal, oil and gas, beginning with the power plants that account for 40 percent of our carbon footprint nationwide.
President Obama has a plan to cut power plant emissions 30 percent by 2030. We can do even better than that, but we need to get started now. The president's Clean Power Plan will help.
The plan lays out carbon reduction targets tailored to each state's energy mix. States decide how to reach the goals and power companies figure out the most cost-effective way to get the job done. Some will get more power from the wind and sun, for example, tune up aging generating equipment or promote efficiency so our families and businesses can do more with less waste.
It's a good plan that deserves our support. It will strike a blow against the central environmental challenge of our time. And it will help protect future generations, special places like the Florida Everglades and all that depend on it to survive.