The
planet is warming up. What does that mean for Rochester?
The
short answer is that nobody really knows.
A climate is a
complex thing. Change one little part of it and you may change the whole thing
— and in unpredictable ways. Still, that doesn’t mean scientists can’t make
some sound educated guesses about what could happen. And if any of those
guesses prove accurate, the Rochester of tomorrow
could be a very different place from the one we know today.
Despite the complexity of all the systems involved,
there are a few easy places to begin to understand the effects of climate
change in Rochester.
When it comes
to deducing what the weather of tomorrow might be like, it’s helpful to start
with the weather of today. That’s where Dr. Jose Maliekal comes in. A professor
at Brockport for the past 15 years, Maliekal has a PhD in meteorology, and
focuses many of his classes on climatology and climate change. He’s careful to
point out the inherent uncertainty in making predictions based on current
predictions.
Throughout
the course of an interview with City Newspaper, he kept adding qualifiers like
“You never know these things for sure” and “No one can say for sure.” Part of
that uncertainty comes from the fact that changing a single variable has the
potential to result in multiple outcomes, some of them radically different from
one another. Maliekal illustrates what he means with an example:
Say
you have a temperature increase. Warming increases evaporation, pumping more
moisture into the atmosphere. One of two things could happen to that water
vapor. First, it could form low-lying clouds. Those clouds, in turn, would have
a cooling effect, blocking radiation from the sun that would otherwise heat
things up. In that case, such a change would be self-correcting.
But
let’s say that instead of forming low clouds, the extra water in the atmosphere
forms high clouds. “High clouds tend to have a warming effect,” says Maliekal,
since they trap existing warmth and let more of the sun’s rays in. That “could
accelerate the warming trend we have in place,” says Maliekal. Instead of
self-correcting, the system would be self-reinforcing.
(A
process similar to the latter scenario has contributed to the global warming
now taking place, Maliekal says. Typically, the earth reflects about 30 percent
of the sun’s radiation into space. Some of that is reflected off the icy
surface of glaciers. With glaciers around the planet receding as temperatures
rise, there’s less ice to reflect radiation, and more gets absorbed by the
planet, further raising surface temperatures.)
It’s
complex possibilities like this that lead Maliekal to say that “no one can say
for sure what is going to happen,” before quickly adding “We do, however, have
some reasonable hypotheses about what could happen.”
So
what are those hypotheses? Here’s one of the more surprising ones: “Should the
climate change, there is the possibility that lake effect would increase,” says
Maliekal.
Lake-effect
snow is produced when there are extreme disparities in temperature between the
lake water and the atmosphere above it, he explains. If the LakeOntario is storing
more heat from the atmosphere during the spring and summer and losing less
during the fall and winter, its overall temperature will be warmer.
That
means that, assuming we still get periods of cold arctic air, there’s a higher
likelihood that the area will experience the temperature disparities that
create lake effect snow. (Not everyone agrees with Maliekal on this point. In
2000 the University of Michigan’s Peter
Sousounis authored a paper suggesting that the temperature could rise high
enough that even our cold spells might no longer be cold enough to trigger the
lake effect.)
But
there are plenty of other changes that are likely to be less pronounced, or
less surprising.
Ice
cover on the Great Lakes and smaller bodies of water is
dwindling, for example. (With the exception of the shallow Erie, the Great Lakes rarely freeze
over completely, but cover around the shorelines has been shrinking.) What does
that mean? “No one can say for sure,” says Maliekal.
The
same is true for the yearly hydrological cycles the Great Lakes go through.
The lakes tend to swell in the spring, with rains and snowmelt runoff, then ebb
to seasonal lows in the autumn months.
“Studies
have shown that in recent years there has been a shift in that pattern,” says
Maliekal. Both the spring rise and the fall drop are happening earlier in the
year. And no one’s sure what that trend might mean if it continues.
Other likely
changes to the local environment come with more obvious consequences. For instance,
Maliekal says that Rochester, like the
rest of the Great LakesBasin, will become
a drier place overall. That will lead to higher extremes, he says. We’ll
experience both “slightly prolonged droughts and increased flooding.”
The
higher temperatures and relatively scarcer availability of water will affect
agriculture, but it will also affect water levels in the Great Lakes. They could
drop by as much as 3 feet in the next 50 years.
That
change may, in fact, be the one that has the biggest impact on daily human
activity in the Great Lakes basin. Ironically, while ocean
shorelines around the world will be encroaching on human settlements as sea
levels rise, here in the Great Lakes water levels
will likely fall. In fact, Environment Canada, the branch of the Canadian
government that tracks these things, estimates that the outflow of the St. Lawrence
River, which drains all of the Great Lakes basin, could
diminish by as much 20 percent.
The
reason for the divergent fate of coastlines between oceans and inland bodies of
fresh water like the Great Lakes is that the
lakes are well above sea level (LakeOntario’s elevation
is 243 feet). And they won’t receive any outflow from the melting glaciers and
polar ice caps that will swell the world’s oceans. None of those are in the Great Lakes’ watershed.
And
while droughts and lower water levels will become the norm, some of the water
we still get could become more of a problem, since it will come more often in
the form of extreme events, like thunderstorms. That, combined with a drier
landscape, will mean more frequent and destructive flooding. With more floods
and storms, erosion will become a larger problem than it is today, threatening
things like agriculture and the value of waterfront homes.
Lower
levels on the Great Lakes could also have an impact on
commercial navigation. That in itself won’t mean much to Rochester, which hasn’t
relied on commercial shipping as an important part of our economy in a long
time. But the pressures on shipping could have some indirect impacts on this
region. Environment Canada warns that
dredging channels to keep commercial shipping moving apace might stir up
dangerous toxic chemicals. Since plenty of the Great Lakes navigational
infrastructure is upstream from Rochester, our
community’s LakeOntario public water
intakes would be at risk.
Lower
lake levels in the Great Lakes could also hit one other sector
pretty hard: hydroelectric power generation. If water outflows decrease,
massive projects like those along the Niagara River and Gorge near Buffalo and
along the St. Lawrence in Massena could see their ability to generate power
diminished, even while energy demands, if they follow today’s trends, continue
to spiral upward.
Besides the
change in lake levels, there’s one other area that stands to see a dramatic impact:
the region’s flora. In fact, plants are already starting to undergo changes as
a result of warming that’s already occurred.
Grapes
are blooming an average of 6 days earlier than they did in the 1960s, while the
average bloom dates for apples has shifted 8 days earlier over the same period.
For lilacs, it’s four days earlier. (At that rate, we’ll be looking at an April
Lilac Festival in the not-too-distant future.)
Plant
ecologist David Wolfe has witnessed, and in some cases documented, these
changes. Wolfe is a professor at Cornell’s School of Agriculture, and it
shouldn’t come as a surprise that farmers are among the most concerned about
these trends.
“Agriculture
is very dependent on the weather,” says Wolfe. “This might be a harmless
thing,” he adds, but his list of concerns seems to undermines that.
For
starters, believe it or not, there’s the problem of frost.
“One
concern is that if the weather’s getting better earlier, you could actually
have increased frost damage,” says Wolfe. Sound counterintuitive? It’s not.
While average temperatures are getting warmer, coaxing flowers to bloom
earlier, that doesn’t mean that extreme temperatures will become any less
extreme. (Last week’s temperatures that flirted with the freezing mark illustrate
his point.)
That
means that plants germinating and flowering ever earlier run an increasingly
higher risk of being killed or damaged by late spring frosts.
The
changing temperatures also hold the potential to play havoc on traditionally
cold-weather crops in another way. It’s a process called “vernalization.”
That’s a fancy scientific term for something akin to hibernation in some
plants.
“They
need a certain number of days during the winter where the temperature remains
low,” says Wolfe. And those days have to be consecutive, not spread out over
the course of a winter, Wolfe says. Exactly how many days, and what the
threshold temperature is, varies from plant to plant, but the basics remain the
same. The plant requires those conditions to produce the hormones it needs. If
that doesn’t happen, the plant’s growth — and the crop it yields — can
suffer. Apples are one prominent local crop that is subject to this biological
requirement.
Blueberries
and winter wheat are two other examples. And like the ever-earlier bloom dates,
this effect is already happening now.
“For
years with warmer winters we get lower apple yields,” says Wolfe. “I think this
past winter was [mild] enough to have that kind of effect.”
The
way in which global warming is occurring specifically in Western New
York exacerbates this problem. While average temperatures have
increased about 1.1 degrees Fahrenheit globally in the past century, they’re up
by 1.8 degrees here. Look just at winter temperatures, though, and the increase
in average temperatures jumps to 2.8 degrees, says Wolfe.
Of
course, all that warming isn’t all bad. There are a few positive outcomes to be
had, like extended growing seasons, which may eventually allow crops
historically grown further south to thrive here. And one industry in particular
stands poised to reap a good deal of benefits:
“There’s
anecdotal evidence that this is actually good for grapes,” says Wolfe.
While
North
America has a few native varieties of grape, he notes, these are
too sweet to be favored by serious winemakers for anything more than a few
novelty wines. Instead, the wine industry favors the traditional European
strain of the fruit, vitus vinifera.
In the past, that might have been a problem.
“They
have a little trouble with our historical winter climate,” Wolfe says of the vitus vinifera grape. Temperatures of 12
degrees below Fahrenheit or lower damage the vines of the imported variety, he
explains.
“We’ve
had very, very few winters where it got that cold” since the 1970s, says Wolfe.
That’s about the same time wine production really took off in the Finger Lakes, he says.
Still, the
downsides for agriculture probably outweigh the benefits. One reason: in addition to the
challenges to plants that are built into their own biology, warming will bring
a whole host of changes that they may be ill-equipped to deal with.
One
of the gravest potential threats along these lines is invasive species. Insects
and plant diseases, which can wipe out species of plants, and other plants
species, which can out-compete them, may be able to move into a territory as
climatic conditions change.
“Insects,
diseases, and weeds that are currently south of us will be with us,” says
Wolfe.
That’s
a potential threat to all plant species, but typical agricultural crops may be
among the most vulnerable, since “a lot of crop species have been genetically
programmed to remain a certain size,” explains Wolfe. That genetic programming
puts crop plants at a disadvantage when competing with wild plants, which can
rapidly adapt to changing conditions.
To
make matters worse, “weeds will benefit a lot from warming temperatures” and
higher levels of carbon dioxide, says Wolfe. “People would have to use more
herbicide, since weeds would be healthier,” he adds, a practice that has its
own environmental effects.
Another
possible problem for plants is the change in precipitation patterns.
“It’s
more difficult to predict precipitation than temperature,” says Wolfe. Like
Maliekal, he expects to see a general decrease in store for this region, with
the exception of extreme events during the summer months.
“Although
you might get the same amount of water as in the past, if you get it all in a
few chunks you could see some short-term droughts,” he says. And in areas that
are outside the lake-effect belt, a decrease in snow cover could deprive the
soil of insulation. That’s means more freezing and thawing through out the
course of the winter. While that’s not good for plants, it could be even more
disruptive for microbes that live in the soil. Their complex relationship with
plants who share their soil is still a mystery.
“We
don’t really know what it does, but it has an impact,” he says.
Yet
another potential problem for plants is the increased heat itself. Plants,
especially cold-weather crops, can suffer from something called “heat stress,”
which as the name implies, weakens the plant and can potentially reduce crop
yields. It also means the plants will require more water, hence more
irrigation, even while supplies of the precious resource will be dwindling.
(Although
not as well versed on the animal side of farming, Wolfe says that the dairy
industry will face similar problems, since cattle like a cool climate and are
also vulnerable to heat stress. Temperatures between 45 and 70 degrees
Fahrenheit are optimal for milk production. “Farmers can probably adapt,” he
says, “but it becomes expensive.”)
All
this potential for change is troubling, since all of us depend on agriculture
for our food.
Food
costs may go up a bit, but Wolfe says he doesn’t foresee huge price spikes. And
some food production may actually come back to the area for a variety of
reasons. In addition to higher fuel costs, which may make shipping fruit from California (not to
mention New Zealand) less
profitable, our area will have relatively more water than many other
breadbasket regions.
And
as the temperature continues to inch upward, crops’ ranges will swing
northward. (How does a nice crate of Finger Lakes oranges
sound?) While many of us will not see such changes in our lifetimes, that
doesn’t mean farmers can ignore them for now.
“Farmers
are going to have to adapt,” which may include making expensive investments in
new equipment, says Wolfe. “Farmers who are growing cabbage today might be
growing something else.”
That
sounds fine in theory, but at some point farmers are going to have to make the
leap from one crop to another, and the process could be messy. Farmers will
essentially have to make guesses about whether to change crops and when.
“Some
will guess right and some would guess wrong,” he says. Those decisions may
await farmers in the not-to-distant future, perhaps in as little as 10 to 20
years, Wolfe says.
Yet
despite that assessment, he’s still relatively upbeat about the future of
agriculture here.
“I
don’t think it’s totally doom and gloom for agriculture,” says Wolfe. “It’d be
a little more doom and gloom” for the southeastern United
States, he says, but farmers here will be
able to adapt for the most part.
“The
agricultural community is poised to take advantage of this opportunity,” he
says.
If
all this still sounds remote and abstract, consider the parallel effects that
changes in vegetation will have on the average homeowner. Grass and other
ornamental plants will be subject to the same problems of heat stress and its
attendant demand for more watering. And they’ll all face the same onslaught of
healthier weeds and invasive plants, insects, and diseases. (More pesticide,
anyone?)
Another
nasty surprise that a warming trend has in store for us: “Almost certainly the
allergy season will be coming earlier,” says Wolfe, since major culprits like
ragweed do quite well in heat.
It’s less
clear how natural ecosystems will handle the shift in climate.
“The
fabric of our forests and natural ecosystems is going to change,” says Wolfe.
But it’s difficult to predict exactly how.
“It’ll
happen slowly, I think,” says Wolfe. “Over 10 to 50 years, we’re likely to see
a big change.” That’s the time period it takes for a new generation of trees to
grow up.
Some
of those changes may be subtle, but others probably will not. Maples, for
instance, which are responsible for almost all the brilliant colors we witness
here each fall, could be out-competed here. (Imagine a fall of dull brown and
wan yellow.)
Like
the farm, lawn, and garden ecosystems tended to by humans, natural areas face a
host of new pest and competitors.
“They
could become more and more dominated by invasive species,” says Wolfe.
And
like the climate itself, ecosystems are complex, which means small shifts can
leave them vulnerable to big changes.
“One
of the complicating factors is that every species is different” in its
sensitivity to climatic changes, says Wolfe. “That creates the problem of
synchrony.” Wolfe is talking about the timing of the finely-tuned mechanisms
that ecosystems evolved over time to sustain themselves. For example, if
flowering plants continue to bloom earlier each year, but the bees they rely on
to pollinate them don’t adjust as quickly, those plants might not be able to
reproduce.
“That
would be devastating to a plant,” Wolfe says. Such looming possibilities mean
that ecosystems “could be pretty badly disrupted.”
Hot
flashes
What
to expect — when you’re expecting climate change:
•
More (or less) lake effect snow
•
Uglier fall foliage
•
Fewer (and less healthy) apples and apple orchards
•
Better wine and more varieties of it
•
A bigger, badder allergy season
•
More expensive food
•
More local food
•
More floods
•
More droughts
•
More bugs
•
Fewer (and more scraggly) lawns
•
Scarcer water
•
Less hydroelectric power
This article appears in May 3-9, 2006.
