As a climate scientist living in central Pennsylvania, it would be remiss of me not to comment on the recent Groundhog Day, because human action may soon change it forever.

The modern celebration, derived from an age-old European tradition, takes place every Feb. 2, in Punxsutawney, Pa., about 100 miles west of Penn State University, where I teach. According to legend, if the groundhog — who also goes by the name Punxsutawney Phil — sees his shadow, there will be six more weeks of winter weather. If he does not, there will be an early spring.

When Phil emerged from his burrow this year, he “spoke” to an event official in “Groundhogese,” and his prediction of more cold weather was then translated for the waiting public.

Sadly, it appears that global warming may soon add Phil to the ranks of the unemployed. Or, at least, the inaccurate. With the warming of 7 to 14 degrees Fahrenheit predicted over North America by the end of this century, if we continue to increase greenhouse gas concentrations at current rates, the answer will become simple: Spring will come early every year.

While this may seem like a pleasant outcome, it could in fact spell real trouble for people, plants, animals and entire ecosystems. Indeed, even with a climate shift of a couple degrees, there will be significant implications for our environment.

At our current rate of carbon emissions, climate change models consistently predict a significant rise in sea levels, which will dramatically increase flooding in coastal regions. And we would see other extreme weather events such as droughts and extended heat waves.

Living things have adapted to the timing of the seasons over many thousands of years. Here we are changing the timing of the seasons on time scales of decades. Plants and animals just don’t adapt well to changes in such short intervals. And modern society is unlikely to fare much better.

According to calculations by NASA’s Goddard Institute for Space Studies, the National Oceanic and Atmospheric Administration and the U.K. Meteorological Office, 2005 was the hottest year on record for the Northern Hemisphere. At roughly 1.3 degrees Fahrenheit above the historical average, the research also indicates that 2005 was either the hottest or second-hottest year in mankind’s history.

While some may quibble about whether 1998 or 2005 was warmer — and they are very close, depending on which compilation of records you use — that’s not the key point. What’s important, and what makes 2005 so remarkable, is that this anomalous warmth occurred during a year when there were no natural factors that could be blamed.

This year, we saw January average temperatures of 5 to 16 degrees warmer than average over most of America. This is a rare pattern indeed. Usually when one part of the United States, such as the East Coast, experiences unusually warm weather, some other region, such as the Rocky Mountain states, encounters unusually cold temperatures. This has to do with the natural “wiggles” of the jet stream that change from one month to the next. The pattern we’re seeing so far this year, however, where the entire nation is unusually warm, only occurs when the entire jet stream has migrated far north from its usual position.

As numerous scientists have noted before, there is no way to ascribe any single weather event, or even an entire anomalous season, to global warming and climate change. But what we can say is that the temperature pattern we’ve seen this January is similar to the kind of pattern that models predict as being normal in just a few decades, given “business as usual” scenarios of fossil fuel burning and greenhouse gas increases.

Global warming is thus likely to “load the dice,” making the kind of January temperatures that might seem remarkable by past experience increasingly probable, and hence more frequent.

In the movie “Groundhog Day,” Bill Murray’s character finds himself having to repeat the same day, Feb. 2, over and over again. At one point he exclaims, “It’s cold today; it’s cold every day.” Were the movie to be remade several decades in the future, the character might instead have to lament: “It’s warm this winter; it’s warm every winter.”

Michael E. Mann is an associate professor of meteorology at Penn State University and director of the Penn State Earth System Science Center.