We have completed another year of meteorological
extremes and records: fires, famines, floods, droughts, tornadoes, hurricanes,
blizzards and heat waves. Less visible, but more ominous, is the decrease in
biodiversity, the loss of Arctic ice, glacial melting, escalating
concentrations of greenhouse gases (ghg) and increasing ocean temperatures and
acidity levels.
Climate and weather are complex natural phenomena but
the way global warming (or “global weirding” as climatologists are calling it)
is playing out is fairly simple. Increasing levels of atmospheric ghg, such as
carbon dioxide and methane, are trapping heat close to the earth and warming
the oceans, air and land. In the words of climatologist Gerald Meehl, ghg are
the steroids of climate change.
This warming trend is increasing surface evaporation
and because warm air holds more water vapour, the lower atmosphere now has a moisture
content 4 percent more than 40 years ago. The increased heat and water vapour
in the atmosphere provides the fuel and energy that power the destructive winter
and summer storms that are becoming more prevalent each year.
Global warming is also shaping changes in the upper
atmosphere. The inconsistency of air masses and the variability of circulation patterns
are creating winds that are increasingly unpredictable. These winds are
altering the nature of precipitation, triggering more rain and snow in some
places and less than normally expected in other areas.
As ever higher concentrations of ghg – created largely
by burning fossil fuels – drive up temperatures, climate and weather
fluctuations will increase. Welcome to the “new normal.” The stable climate
enjoyed by the planet for 12,000 years is over.
Ghg are heading skyward in another way. The
International Energy Agency announced last year that global emissions in 2010
were the highest in history. Any hope of restricting global temperature
increases to 2 degrees C is vanishing rapidly. This limit is recognized by
governments and scientists around the world as the threshold which, once passed,
could catapult us into climate chaos.
The Arctic is already in climate freefall. Sadly, for
the majority of the Canadian population, it is a case of out of sight, out of
mind. For the north, heating at more than twice the global average, 2011 was the
warmest year on record. The region is poised to experience the first irreversible
climate tipping point on the planet because it is so environmentally sensitive.
The warming and the warning signals are in the north. We ignore them at our
peril.
A dramatic development in the north is the record loss
of the older, thicker Arctic sea ice and its replacement by thinner ice that
melts quickly each summer. The melting process is being expedited by milder
incoming ocean currents, changing wind patterns and by the albedo effect.
Albedo (from Latin for “whiteness”) is the amount of
solar energy reflected into space. As the polar ice sheets with their high
reflectivity melt, more solar radiation is absorbed by the dark surface of
exposed water. The warming water melts more ice, exposing ever more water to
the sun’s rays, thus perpetuating the melting cycle. The process is
self-reinforcing and unstoppable.
Like the Arctic sea ice, the freshwater ice shelves of
Ellesmere Island are rapidly disappearing. Ice shelves, unlike glaciers, are
platforms of ice, anchored on land but protruding into the ocean. As they break
up and move into open water, the remnants become roving “ice islands” and a
threat to shipping. The Ellesmere ice shelves are the only ones in Canada and
since 2000 they have lost half their area.
Thomas Homer-Dixon explained in a Globe and Mail article a year ago how the heat build-up in the
north is also affecting Arctic air masses which in turn have destabilized
traditional wind patterns, such as the west-east flowing jet stream. The
shifting jet stream now frequently flows north-south in winter dragging bitter
Arctic air into the mid latitudes of North America, Europe and Asia. Meanwhile,
the north is experiencing relatively warm winters.
Another problem related to the polar warming trend is
the release and reconstitution of toxic chemicals that have been trapped in
snow and ice for years. These chemicals, originally carried north by winds and
ocean currents or dumped by the military, include DDT and PCBs that are
internationally banned today.
A disconcerting development was the discovery in the
spring of 2011 of a large Arctic ozone hole for the first time. The occurrence
of a northern ozone hole is still puzzling atmospheric scientists but it
appears to be the result of a lingering problem of long lasting chlorine
compounds exacerbated by increasing ghg emissions and upper atmosphere
temperature fluctuations.
The sleeping giant of Arctic climate change, however,
is the melting permafrost. One quarter of the land mass of the northern
hemisphere comprises frozen water, soil and rock. Embedded in the frozen
organic matter are huge volumes of inert carbon dioxide and methane.
Similar to the albedo effect, the melting permafrost
is an alarming example of a destructive feedback cycle. The thawing organic
material, amplified by microbial activity, releases vast quantities of carbon
dioxide and, especially, methane. This action will accelerate the warming
process and intensify the melting of the permafrost and that, in turn, will further
increase emissions of the two gases in a destructively uninterrupted cycle. As Professor
Homer-Dixon points out, “when warming becomes its own cause” we are in deep trouble.
Scientists estimate that methane emissions in the
north have risen by 30 percent in the past 5 years. Once the permafrost has
melted completely the released carbon dioxide and methane will double
atmospheric ghg concentrations to 800 ppm and that could very well make the
planet uninhabitable for human life. No wonder that climate scientists regard
the melting permafrost as a ticking time-bomb that could nullify all our best
efforts to curb global warming.
As the climate changes, so does the vegetation. The
tree line, for example, is moving rapidly north preceded by an increasing
variety of plants and shrubs that were once foreign to the area. As the climate
warms and the vegetation changes, the migration of birds, insects and animals
follows – an average of 18 kilometres over the past decade according to a York University study. Roosting robins on Baffin Island are one example of
numerous species that are migrating northwards as the Arctic warms. The Inuit
do not even have names for many of the new arrivals.
The fragile Arctic is our climate canary in the
coalmine. The canary is an apt symbol for the climate changes affecting the
north. Ironically, this songbird sentinel of coalminers – though not yet itself
a migrant to the north – may suffocate, not from subterranean methane, but from
surface methane emitted by the melting permafrost. Coal is the common element,
or perhaps villain, in this avian analogy: both its mining and burning produce the
gases that are melting the Arctic.
Longer ice-free periods along the Hudson Bay littoral
are responsible for an increasing incidence of malnutrition among polar bears
at a crucial time in the spring when they normally feed on ring seal pups.
Professor Ian Stirling, a world renowned polar bear expert, estimates that the
iconic animals will have disappeared from Hudson Bay by 2040 largely because of
the impact of deteriorating ice conditions on their hunting and feeding practices.
Again we appear to have a climate culprit in the
decimation of most of the major caribou herds across North America. Like the
polar bears, the arrival of an earlier spring – 3 weeks earlier in the past 30
years – is also affecting the feeding habits of the caribou. The pregnant cows
are now arriving at the grazing lands, after an arduous migration, weeks after
the new shrubs are at their peak nutritional level.
According to Liv Solveig Vors of the University of
Alberta, warmer summers are producing an increased incidence of mosquitoes,
flies and parasites that both torment and weaken the caribou. The thawing
permafrost is slowing down their migrations, imposing further stress on
weakened animals and making them easy prey for predators.
Some native species will adapt to the climate of the
“new north” but others will be unable to adjust to the rapid changes and extinction
rates will escalate, resulting in a tragic loss of genetic diversity.
Climate change is also disrupting the life of
communities in the north. The melting permafrost is causing building
foundations to collapse and roads to buckle in the summer. Many villages are
dependent on ice roads for their supplies but the warming trend is preventing
safe crossings of lakes, rivers and muskeg. The shorter season for ice roads has
resulted in emergency airlifts of food to northern communities at considerable
expense.
The changing ecosystem of the north has had a dramatic
impact on the lifestyle of the indigenous people. In recent years, hunting,
trapping and fishing have offered fewer economic benefits but they have
nevertheless provided subsistence opportunities and an accompanying sense of
dignity, identity and independence. As the wild life declines and traditional
lifestyles are transformed, these communities are becoming increasingly
demoralized.
How sadly ironic that our first climate refugees may
be from the north and not, as anticipated, from the warmer areas where millions
will soon be displaced by rising sea levels, drought and famine. We should hang
our heads in collective shame at the prospect of fellow Canadians abandoning
their traditional homelands because of the impact of our excessive lifestyles
on the climate of the north – a climate that has shaped and sustained their
unique way of life over many centuries.
