The Timing Of Seasonal Events

The loggerhead sea turtle is another species being documented as subjected to the negative effects of global warming. John Weishampel, an associate professor at the University of Central Florida, has analyzed long-term records of a 25-mile (40-km) length of Florida coast, which represents one of North America's key breeding grounds for the loggerheads and has discovered that the turtles today are coming ashore to lay their eggs about 10 days earlier than they were in 1989. Suspecting global warming as the cause for the change in breeding behavior over the past 20 years, he analyzed water temperature data that was collected offshore and found that temperatures had increased by 1.5°F (0.9°C) over this time period.

Weishampel's findings are consistent with findings of other scientists worldwide who are studying different ecosystems for the same reasons. Based on a study published in Global Change Biology in 2007, as global temperatures continue to rise, more discoveries are made indicating that the timing of seasonal events in the life cycles of both plants and animals are making dramatic changes—shifting out of sync with longtime patterns.

Trees worldwide are budding earlier in the spring and losing leaves later in the fall because rising temperatures are causing spring warm-up to occur earlier and summerlike temperatures to linger later in the fall. Animals are also exhibiting natural shifts by migrating, mating, producing young, and emerging from hibernation earlier in the spring. Other animals have also been similarly affected. Based on a report from the Pew Center for Global Climate Change in November 2004, more than three dozen scientific reports have linked global warming to ecological changes in the United States. The shifts are consistent across species, ecosystems, and geographic regions throughout the country. The following list summarizes the findings of the reports:

• Plants in Washington, D.C., are flowering 4.5 days earlier than they did 30 years ago.

• Mexican jays in southern Arizona breed about 10 days sooner than they did in 1971.

• Barn swallows nationwide are nesting nine days sooner than they did in 1959.

• In Michigan's Upper Peninsula, birds are returning from their winter migrations earlier in the spring.

• The Eastern Seaboard's Cape May warbler has shifted its range to the north, and if the trend continues, in a century there will be no more Baltimore orioles in Baltimore.

• American robins are arriving to breed two weeks earlier than they did in the late 1970s in response to warmer temperatures in their low-latitude winter habitat. Currently, when the birds arrive, it is still winter. They must wait for the snow to melt before they can feed themselves and their young.

"The yellow-bellied marmots are also responding to higher spring air temperatures by leaving hibernation dens more than a month sooner than they did a few decades ago. But if the mismatch between cues at lower and higher elevations keeps growing, these animals could be in trouble," says biologist David Inouye, of the University of Maryland.

In each case, the species' behavioral change coincides with a temperature increase during the same period.

Camille Parmesan, a biologist at the University of Texas, says, "Climate change is happening right here, right now, and changing life in your own backyard."

Parmesan also says that a major concern is that "any given species is unlikely to respond to changing climate in the same way as others that share its habitat. When this happens, vital links among interdependent species—such as a plant and its pollinator—can be broken, a loss of

Was this article helpful?

0 0
Guide to Alternative Fuels

Guide to Alternative Fuels

Your Alternative Fuel Solution for Saving Money, Reducing Oil Dependency, and Helping the Planet. Ethanol is an alternative to gasoline. The use of ethanol has been demonstrated to reduce greenhouse emissions slightly as compared to gasoline. Through this ebook, you are going to learn what you will need to know why choosing an alternative fuel may benefit you and your future.

Get My Free Ebook

Post a comment