February 03, 2011 - The climate change
models have always predicted that one of the outcomes to expect
from a warming climate is more extreme weather events. And,
looking at world events in recent years, there certainly seems to
be an increase in storms, floods, droughts, extreme temperatures
and large forest fires.
But perhaps this is just a perception brought about by our much
increased interconnectedness. Are we just better informed about
events going on around the globe, so it seems like they are
The one institution in society that has to know exactly what is
going on with respect to extreme weather events is the insurance
industry. Their whole economic survival depends on guessing in
advance the risk of large damaging weather events. If they get it
wrong it can cost them billions. It's no surprise then that they
track and enumerate such occurrences.
The graph below was recently published by Munich Re, one of
world's largest reinsurance companies. It clearly shows that
natural catastrophes have increased substantially over the last 30
years with a trend line on the upswing. These data include all
natural events not just those related to climate and/or
But look! Geophysical events such as earthquakes, tsunamis and
volcanic eruptions show no pattern of increase. All the increase is
due to meteorological, hydrological and climatological events which
have all more than doubled. From an insurance point of view it
certainly looks like the climate is changing.
So why is it that when an extreme weather event occurs
scientists declare that you can't say that any particular weather
event was the result of climate change? James Hansen, the
preeminent climate scientist from NASA, recently
blogged (.pdf) on that question this way:
Finally, a comment on frequently asked questions of the sort:
Was global warming the cause of the 2010 heat wave in Moscow, the
2003 heat wave in Europe, the all-time record high temperatures
reached in many Asian nations in 2010, the incredible Pakistan
flood in 2010? The standard scientist answer is "you cannot blame a
specific weather/climate event on global warming." That answer, to
the public, translates as "no".
However, if the question were posed as "would these events have
occurred if atmospheric carbon dioxide had remained at its
pre-industrial level of 280 ppm?", an appropriate answer in that
case is "almost certainly not." That answer, to the public,
translates as "yes", i.e., humans probably bear a responsibility
for the extreme event.
In either case, the scientist usually goes on to say something
about probabilities and how those are changing because of global
warming. But the extended discussion, to much of the public, is
chatter. The initial answer is all important.
So it is very important to be conscious of how you structure the
message if you want to engage in the great climate change debate.
But one thing seems apparent in these confusing times of sceptics,
deniers, trolls and obfuscators. Gaia doesn't care what we hairless
apes think. She will just keep whacking us with weather until we
Gord Miller is the Environmental Commissioner of