cientific inquiry to understand our world has been an integral part of Western civilization for the past two centuries. One important scientific finding is that the surface atmosphere of our planet is getting warmer. Among global environmental scientists, there is a working consensus that our planet has warmed almost .7 °C over the past century.
The scientific conclusion is that this observed warming is largely attributable to the increasing human production of greenhouse gases, particularly carbon dioxide and methane. As levels of greenhouse gases in the atmosphere increase, more of the sun’s radiant heat is absorbed rather than reflected, and global warming occurs. Other factors have also been examined for their potential contribution to the observed global warming (e.g., solar flares, soot dispersal, planetary orbital oscillations, volcanoes). However, data do not support these other factors as major causes of this phenomenon.
There is also a broad consensus among global warming scientists that as human-produced greenhouse gases continue to accumulate, further global warming and resulting changes in climate are inevitable. The changes include such realities as increased melting of ocean ice, glaciers and permafrost, rising sea levels, greater rainfall and changes in rainfall patterns, continued ocean acidification, proliferation of extreme weather events, alterations in habitat for many species, etc. Today’s scientific challenge is twofold: to predict future rates of global warming with precision and to better understand how different interacting factors will work to slow or further accelerate the rate of global warming and climate changes. In 2007, the UN Intergovernmental Panel on Climate Change cautioned that if the current global warming trend increases by more than 2 °C, a tipping point could be reached beyond which a variety of feedback loops would accelerate the warming process, resulting in more severe climate changes.
Within Canada, there is much indecision and division about these scientific developments.
A small number of individuals and organizations still deny the evidence of global warming or, if they accept that global warming is indeed occurring, reject it as the cause of climate changes. Some attack the personal integrity or motivation of scientists who have published their research findings. Some contend, usually without presenting supporting data for scientific debate, that humans are not responsible for the increase in the global temperature and the observed warming and climate change trends are due to other causes beyond human control. Many see little value in independent scientific research related to this issue.
The largest segment of the Canadian population accept the science-supported claims that global warming is occurring but is not as accepting about the predicted impacts for climate changes. Many are indecisive about or reluctant to make decisions to reduce global warming or to deal with potential climate changes threats. Some question the reliability of current scientific projections of global warming and related climate changes and view calls for significant alterations in behaviour aimed at reducing the human production of greenhouse gases as unnecessarily alarmist. Many point out that taking measures to reduce current greenhouse gas production would be economically costly, socially disruptive and inconvenient for many citizens. They question why Canadians should economically handicap themselves by unilaterally reducing their greenhouse gas production when there are no international agreements binding all countries to do so. Others cite potential economic benefits from climate change in northern Canada brought about by global warming. Many wish the scientific messengers would just go away.
A smaller but growing segment accept scientists’ conclusions that both global warming and climate changes are occurring. They worry that global warming, especially in the Arctic, is accelerating faster than predicted by some early scientific models. They fear that resulting climate changes will be increasingly economically and agriculturally disruptive, will contribute to international instability, and will threaten the lives of large portions of the human population within the next two to three decades. Many support a mix of personal, business and governmental actions to reduce human greenhouse gas production – improved efficiency in energy use, increased renewable energy reliance, reductions in use of fossil fuels, establishment of carbon taxes, strengthened protection of forests, exploration of eco-engineering options, etc. Most want more public funding for independent scientific research into global warming and related climate changes.
Public and political debate in Canada about evolving scientific findings and predictions are essential to any rational planning to deal with global warming and climate changes. The current paucity of such public discussion, particularly by elected politicians, does not bode well for the future.