Climatic changes... and the results of those changes ... could occur within decades or even sooner, and they are becoming a greater
concern for scientists, according to a new paper from the National Academy of
Sciences.
"The most challenging changes are the abrupt
ones," said James White, a professor of geological sciences at the
University of Colorado in Boulder and chair of the report committee. White and
several coauthors of the paper spoke at a press conference Tuesday morning.
The
paper focuses on those impacts
due to climate change that can happen most quickly. Among these are
the rapid decline in Arctic sea ice (above) that scientists have seen in the last
decade and increased extinction pressure on plants and animals caused by the
rapidly warming climate.
Many such changes, according to Tony Barnosky, a
professor in the Department of Integrative Biology at the University of
California, Berkeley, are "things that people in this room will be around
to see." He emphasized that scientists are "really worried about what's
going to happen in the next several years or decades."
"The planet is going to be warmer than most
species living on Earth today have seen it, including humans," said
Barnosky. "The pace of change is orders of magnitude higher than what
species have experienced in the last tens of millions of years."
Other, more gradually occurring changes can still
have abrupt impacts on the ecosystem and human systems, such as the loss of
fisheries or shifts in where certain crops can be cultivated. Rapid loss of ice,
for example, would mean that sea levels rise at a much faster rate than the
current trend, which would have a significant effect on coastal regions. A
3-foot rise in the seas is easier to prepare for if it happens on a 100-year
horizon than if it happens within 30 years.
"If you think about gradual change, you can see where the road is and where you're going," said Barnosky. "With abrupt changes and effects, the road suddenly drops out from under you."
"If you think about gradual change, you can see where the road is and where you're going," said Barnosky. "With abrupt changes and effects, the road suddenly drops out from under you."
The paper did offer two bits of good news. One, scientists
don't believe that climate change is likely to shut down the Atlantic
jetstream, a possibility that had been discussed in some scientific research.
They also don't believe that large, rapid emissions of methane from ice and
Arctic soil will pose a serious threat in the short term, as had been
considered previously.
"Giant methane belches are not a big
worry," said Richard Alley, a professor of geosciences at Pennsylvania
State University and committee member. "These really are systems that will
affect us in the future, but they don't look like they're going to jump really
fast."
The paper recommends increased investment in an
early-warning system for monitoring abrupt impacts, such as surveillance
programs to facilitate closer tracking of melting ice and methane releases, for
example. Right now, investment in those systems is lacking in the U.S., and
monitoring programs have been cut in recent years.
"The time has come for us to quit talking and
actually take some action," said White. He noted that in the modern age,
there are cameras everywhere, yet "remarkably very few of those watching
devices are pointed at the environment."
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