We have
now been told five times. The world is warming and we are warming it. The first
time we were told this was in 1990 when a report published by the newly formed
Intergovernmental Panel on Climate Change announced that climate change was real
and that it could have huge impact on future generations. This report spawned
interest on both sides of the question. Science turned its attention to the
problem and an entire industry was created of experts and others who wanted to
prove science wrong with respect to the causes of climate change.
The
second time we were told was in 1995, when the Second Assessment Report was
published. In addition to presenting the science behind claims that climate
change was indeed a fact, this report calmly illuminated the economic and social
dimensions of the problem.
The Third Assessment Report in 2001 told us
again that there was a sound physical science basis for concerns over climate
change and that the world was vulnerable to a wide range of impacts if it did
not mitigate the effects of greenhouse gases on the composition and behaviour of
our planet's atmosphere.
In 2007, the IPCC Fourth Assessment Report
further responded to questions posed by science concerning the validity of the
claim that humans were indeed the cause of the warming and added further depth
to analyses of impacts and the need for adaptation as a consequence of our
failure to adequately mitigate the problem through the reduction of greenhouse
emissions.
Now, in 2013, we have been told again. Perhaps the most
interesting thing about IPCC's Assessment Report 5 is its calm rigor. It is not
that the previous IPCC reports weren't the object of rigorous research and
wordsmithing. They were. It is a hallmark of the scientific method that IPCC
reports bear the stamp of the highest possible standards of research rigor and
objectivity. As a result of three full years of carefully examining the research
outcomes funded by the Canadian Foundation for Climate and Atmospheric Science,
I appreciate the scientific method more than ever and confidently trust the
outcomes of this report.
What I have observed in my work is that every
time another scientist challenges any aspect of contemporary climate science –
and this happens continually – researchers are forced by the long established
conventions of the scientific method to take that challenge seriously. To
determine if such challenges should be considered, researchers must re-examine
all the knowledge that has been collected and validated with respect to climate
to date so as to test the legitimacy of any given counter claim. This means
testing that counter claim against all the data that has been collected relative
to that claim to determine if what is known currently still stands up in the
face of new questions, new perspectives and new information.
Even when
known deniers and cranks challenge any aspect of the growing body of climate
science, researchers are bound by the scientific method to invert the entire
established knowledge infrastructure on this planet to see to if any given
challenge deserves consideration. This is how science advances over time. On
matters related to climate we have been doing this for forty years.
The
Fifth Assessment Report will provide the clearest view yet of the state of
scientific knowledge with respect to climate change. A total of 209 lead authors
and 50 review editors from 39 countries and more than 600 Contributing Authors
from 32 countries contributed to the preparation of the Working Group I report
alone in Assessment Report 5. That group sorted through and addressed 54,677
critical comments in preparation of the report. Two other working groups will
have done the same.
Once again, every critical objection to the
supposition that the burning of fossil fuels is warming our global climate has
been subjected to analysis and fierce scientific debate. What has happened once
more is that after running objections again and again through the entire
knowledge system we keep arriving back at the same conclusions.
The
global thermometer, it appears, is as indifferent to the psychological tricks of
advertising and unrelenting public relations as it is to economic theory. The
temperature readings keep coming in, but no matter how many times we check them,
the picture that is forming of our circumstances and our future doesn't change.
Our world is warming up and, at the moment at least, it looks like it is going
to warm up a lot more with consequences for everything that matters about where
and how we live today. Five times we have been told. Maybe it is time to
listen.
Bob Sandford is the EPCOR chair of the Canadian Partnership
Initiative in support of the United Nations Water for Life Decade and a member
of the Forum for Leadership on Water.