Pennsylvania
is likely in store for more frequent and intense bouts of drought,
flooding and extreme weather because of rapid climate changes, a Penn State University climate expert said Friday, hours after the release of an international report on global warming.
The
fourth study issued by the Intergovernmental Panel on Climate Change
claims humans are almost certainly the main cause of global warming
since 1950. It also spells out a host of potentially devastating
consequences if escalating levels of carbon dioxide and greenhouse
gases remain unchecked.
But even immediate action to curb
global warming may have little effect on reversing some of those
short-term outcomes, said Michael Mann, Ph.D., a professor of
meteorology and geosciences and director of the Penn State Earth System Science Center.
“Even if we were to stop increasing the concentration of greenhouse
gases in the atmosphere, we would see several more decades of warming
of the oceans,” Dr. Mann said Friday afternoon during a conference call
with state journalists. “It’s virtually certain that we can’t reverse
the changes we’ve seen. The key now is to slow that down so we can cope
with it.”
Dr. Mann, who worked on the last IPPC report issued about five years ago, said Pennsylvania
citizens can already see the impact of climate change. He also spelled
out several areas where global warming could significantly affect the
state:
• Drought and flooding. Warmer, drier summers would lead to more
persistent and intense droughts, threatening the state’s
multibillion-dollar agriculture industry.
Conversely, warmer ocean temperatures may trigger greater portions of intense rainfall, as storms over the Atlantic Ocean pick up and retain more moisture than before, Dr. Mann said. He pointed to the June floods that ransacked eastern Pennsylvania as a prime example.
Meanwhile,
warmer sea-surface temperatures are believed by many scientists to
increase the intensity of some storms and hurricanes in the Atlantic.
• Weather extremes. More intense summer heat waves would threaten urban populations in cities like Philadelphia and Pittsburgh. Warmer winters and earlier springs also could devastate the state’s plant and animal populations, which rely on seasonal cues.
• Sea level rises. Evidence that the Greenland ice sheet is melting at an accelerated rate means sea levels could rise by three feet within the next century, Dr. Mann said.
Decades
of greenhouse gases and carbon dioxide emissions may have sealed the
short-term fate for the state, as well as the planet as a whole,
meaning those more intense droughts, floods and weather oddities are
virtually inevitable, he said.
But
people can take steps to ensure that more drastic consequences don’t
occur. Persistent global warming could cause further melting of ice
sheets, triggering catastrophic rises in sea levels that could alter
the topography of the East Coast, he said.
“If we warm the system any more, we’re basically committed. We will ultimately force the melting of the Greenland
ice sheet. That’s something we probably can’t afford to allow to
happen,” Dr. Mann said. “Most scientists studying this problem believe
we can still avert that.”
The climate change report also
comes a day after Gov. Ed Rendell unveiled a new plan to curb energy
dependence and cut energy costs across the state. His “Energy
Independence Strategy” pushes energy conservation and the use of
alternative fuels, hoping to cut energy bills for Pennsylvania citizens by $10 billion over the next 10 years.
The state plans to create new laws, regulations and an $850 million
Energy Independence Fund. The governor is expected to spell out a
comprehensive strategy in the next three months.
Pennsylvania produces more global warming pollution than every state but Texas and California, according to PennEnvironment, a Philadelphia-based environmental advocacy group.
“Sections of this report read like the Book of Revelations. But there’s
still time to protect future generations if Congress and our state’s
leaders in Harrisburg put strict limits on global warming pollution,”
Nathan Willcox, energy and clean air advocate for PennEnvironment, said
in a news release.
A review of the past two months of unusually warm weather seems to bolster the case for climate change.
The average temperature in December was 6.5 degrees above the normal
31.4 degrees. Last month finished 5.1 degrees above the normal 26.3
degrees, according to Accuweather senior meteorologist Bob Smerbeck.
A dozen days in January topped the daily normal temperature by at least
10 degrees. That includes a staggering 64 degrees on Jan. 6, which was
30 degrees above the normal temperature.
Meanwhile, snowfall totals were about a third of the average 13 inches.
Overall, though, this January failed to crack the top five warmest on record, Mr. Smerbeck said.
All but one of those five have been registered since 1990.
