Huge study documents changes from climate warming
Pastor Dale Morgan
Huge study documents changes from climate warming*
By Doyle Rice, USA TODAY
A landmark new climate study released today reports that global warming
is already changing the life cycles of thousands of animals and plants —
as well as hundreds of physical systems — worldwide.
It documents rapid glacier melts in North America, South America and
Europe; trees and plants sprouting leaves much earlier in the spring in
Europe, Asia and North America; permafrost melting in Asia; and changes
in bird migration patterns across Europe, North America and Australia,
all in response to rising global temperatures.
While previous studies have looked at single phenomena or smaller areas,
this is a new analysis on a continental scale looking at data that had
not been previously assembled together in one spot, says lead author
Cynthia Rosenzweig, a scientist at NASA's Goddard Institute for Space
Studies in New York.
By analyzing data from each of the Earth's seven continents and the
oceans, the study paints a clear picture of a world that's been
undergoing rapid transformation in just the past few decades due to
climate change.
"Humans are influencing climate through increasing greenhouse gas
emissions, and the warming world is causing impacts on physical and
biological systems attributable at the global scale," Rosenzweig says.
"These are things that are happening now, not projections of future
changes."
The study appears in this week's British scientific journal Nature.
Rosenzweig and her colleagues compiled data on about 28,800 plant and
animal systems and 829 physical systems, all of which showed documented
changes over the past few decades.
The study found that 95% of the observed physical changes, and 90% of
the biological changes, are consistent with what would be expected from
warming temperatures.
Some of the physical changes include:
•Melting glaciers on all continents, specifically in Alaska, Peru, and
the Alps.
•Earlier break-up and thinning of river and lake ice in Mongolia.
•Declining mountain snowpack in western North America.
•Earlier spring runoff in North America.
Some of the observed effects on living things include:
•Movements of species to higher latitudes and altitudes throughout the
Northern Hemisphere.
•Population of emperor penguins has declined by 50% on Antarctic Peninsula.
•Rapid advance of spring arrival of long-distance migratory birds in Europe.
"It was a real challenge to separate the influence of human-caused
temperature increases from natural climate variations or other
confounding factors, such as land-use changes or pollution," says study
co-author David Karoly, a climate scientist at the University of
Melbourne in Victoria, Australia. However, scientists reported in the
study that "these temperature increases at continental scales cannot be
explained by natural climate variations alone."
Rosenzweig says that the 1970 — 2004 time period was selected because it
coincides with the rapid recent warming of the planet. During that time,
the Earth's temperature rose by about 1 degree F. She points out that a
global temperature rise of 2 to 11 degrees by 2100 — as predicted by the
Intergovernmental Panel on Climate Change in 2007 — only "heightens the
concern of what's happening now."
The data show that changes are most notable in North America, Asia and
Europe — mainly because many more studies have been done there, says
Rosenzweig.
On the other continents, including South America, Australia and Africa,
documentation of changes in physical and biological systems is sparse,
although there is strong evidence there of human-influenced warming itself.
The study builds upon the consensus of the IPCC, which in 2007 declared
manmade climate warming "likely" to have discernible effects on
biological and physical systems.