Early birds, early blooms show effects
of global warming in Michigan
Published February 7th, 2005
Ice chunks the size of Manhattan are breaking loose in
Glacier National Park is losing its glaciers.
Everywhere scientists look in polar and colder climates,
they see evidence of warming temperatures.
But is global warming affecting places with more moderate
climates such as Michigan?
Yes, scientists say, but in more subtle ways.
Many migratory bird species are arriving here earlier
in the spring and some flowers are blooming earlier than
"There isn't a lot of hard data since there weren't
a lot of studies done earlier that we can compare to now,"
said Steven Bertman, professor of chemistry at Western
"What we do have is serendipity. If someone did
a study 30 years ago, we can use it, but it wasn't necessarily
done for climate change. They weren't that prescient."
David Karowe, WMU associate professor of biological sciences,
who teaches a graduate-level class on climate change,
said plenty of temperature data exists here but hasn't
been carefully analyzed.
There are a number of factors, however, that could skew
results, he said. Bigger cities, for example, are "heat
islands" that didn't exist in the past and could
contribute to the seemingly higher averages.
A better measure, he said, are the biological and ecological
changes that are already observable here.
"Biological events like when flowers bloom and when
birds arrive are strongly correlated with temperature,"
Jeff Price, director of climate-change-impact studies
for the American Bird Conservancy, noted in a recent National
Wildlife Federation publication that a long-term study
in Michigan's Upper Peninsula found that 15 spring migrants,
including the rose-breasted grosbeak and black-throated
blue warbler, were arriving up to 21 days earlier in 1994
than in 1965.
Terry Root, of the Center for Environmental Science and
Policy at Stanford University and formerly at the University
of Michigan, said in a recent published interview that
80 percent of the bird species she has studied are arriving
in breeding grounds earlier in the spring -- consistent
with expectations linked to global warming.
Some of the species she studied are native to Michigan.
Karowe said that, even at this very early stage, "we're
starting to see widespread changes in ecosystems, apparently
in response to climate change."
One of the most worrisome possibilities, he said, is
that "different species may advance their timing
to different extents, resulting in a disruption of normal
and beneficial synchrony within ecosystems."
For instance, he said, there's some evidence that the
timing of the flowering of annual plant species has advanced
faster than perennial plants.
If insects that normally pollinate these flowers hatch
at the wrong time, the plants may have a tougher time
getting pollinated as global warming continues, he said.
In April 2003, the Union of Concerned Scientists and
the Ecological Society of America released a report on
the potential impact of climate change in the Great Lakes
states, including Michigan, based on an analysis by a
number of university and government scientists.
They predicted that Michigan will be warmer and drier
over the next century. By 2030, Michigan's climate will
resemble Ohio's today, they said, and by the end of the
century it will be more like northern Arkansas is now.