Augusta could be a very different place in the not-so-distant future.

Imagine a Masters Tournament held in March to enjoy azaleas that fade before April, or alligators as far north as Appling, or dams and levees strengthened to repel frequent and more ferocious floods.

The scenarios sound whimsical, but they are not fiction.

Springtime is inching forward in the Southeast where - at least anecdotally - the azaleas that lure thousands of golf fans in April are less and less predictable; and the ornate wood ducks that hide within our swamps are breeding earlier - and more often.

But the imprecise phenomenon known as global warming goes far beyond our songbirds and flowers. It is serious business; scientists predict it will likely alter our world in dramatic ways.

"There are more consequences in more and more places," said Dr. James Wang, an atmospheric scientist with Environmental Defense, which monitors global warming issues worldwide.

Thousands of miles from Augusta is Greenland's spectacular Sermeq Kujalleq glacier, which has retreated seven miles since 1960 as warming oceans have melted ice frozen for tens of thousands of years.

In Wisconsin, six decades of careful study have documented precise changes: The first song of the northern cardinal is heard 22 days earlier than before - and the forest phlox and butterfly weed begin to bloom at least two weeks earlier.

Should people in Augusta care?

Absolutely, according to Dr. Wang, whose organization can cite studies predicting everything from floods and droughts to more hurricanes and vanishing coastlines along Georgia's barrier islands.

The truth remains subject to speculation, and likely will end up somewhere between the apocalyptic quatrains of Nostradamus and the paranoia of Chicken Little.

"Already, human-caused global warming has doubled the frequency of the deadly heat waves like the one that hit parts of Europe last year," he said. "You can look for some of that in Georgia, and also look for higher temperatures and more frequent, intense rainfall."

As temperatures warm, evaporation increases, he said, which means more water vapor in the atmosphere that returns to the earth as rain or snow.

Models used by the Intergovernmental Panel on Climate Change indicate rainfall in Georgia could increase as much as 40 percent in summer and fall, with sea levels rising as much as 25 inches near Fort Pulaski and Savannah by 2100.

Some local changes are already evident.

Sid Mullis, the director of the Georgia Extension Service office in Augusta, which advises farmers and gardeners on planting times and other issues, said brochures produced for this area in the 1960s and '70s are already obsolete.

"In our publication on vegetable gardens and fall gardens, the brochure says to plant in August," he said. "That may have been the case a long time ago, but now it's still way too hot. The stores don't even stock the plants as early as our brochures say to do it."

One of the more compelling - and most documented - local impacts of climate change has occurred among populations of wood ducks, which Savannah River Ecology Lab scientist Dr. Robert Kennamer has monitored for three decades.

His data show the colorful ducks now begin their breeding season a full month earlier than they did in the 1970s. Though the broader breeding window seemingly could mean more ducks, it also opens a longer season for parasites that can harm waterfowl. The result, he said, remains unclear.

Climate change is also known to affect another creature of the Southeast: the alligator, which has survived 200 million years of temperature changes and numerous ice ages.

Walt Rhodes, a South Carolina Department of Natural Resources wildlife biologist, has studied the creatures for more than a decade and learned that even subtle changes in temperature can affect the male-female ratio of young alligators.

"There's roughly a 6 degrees Celsius window for alligators to breed," he said. "At the two extremes, you get an all-female hatch."

Thus, the creatures are able to adapt to change by producing more females (which can reproduce) when temperatures begin to get too hot or too cold.

"That means alligators can change with the environment and move away from - or toward - the equator," Mr. Rhodes said. "Conversely, if we get into a cooling period, they would continue to shrink their range."

Subtle changes in the bloom of plants, or the laying of a particular bird's eggs, don't initially appear significant to some. But studies by the Pew Center on Global Climate Change indicate otherwise.

"The timing of important ecological events, including the flowering of plants and the breeding times of animals, has shifted, and these changes have occurred in conjunction with changes in U.S. climate," a report from the center states.

If all changes among species that are dependent upon one another are equal, the impact is minimal.

But if the effects vary, the consequences can be catastrophic.

For example, the Pew study said, if butterflies depend on nectar from a certain flower to reproduce, and climate change causes the butterflies to emerge before the needed flowers bloom, it could cause the species to vanish.

Dr. Wang said it is possible some of the changes already observed are broad cycles in nature not yet fully understood.

"It's still not complete or conclusive that all these recent events are influenced by global warming, but it's not out of the question either," he said. "But as time goes by we expect the changes we see to be more and more dramatic."

Global warming could be slowed by changes in greenhouse gas emissions, he said.

"If we slow down, that could slow climate change," he said.

Reach Rob Pavey at 868-1222, ext. 119, or rob.pavey@augustachronicle.com.