The Canadian Federation of Earth Sciences Scientific Statement on Climate Change – Its Impacts in Canada, and the Critical Role of Earth Scientists in Mitigation and Adaptation

• Published in: Geoscience Canada
• Main Authors: Burn, Christopher R., Cooper, Mark, Morison, Stephen R., Pronk, Toon, Calder, John H.
• Format: Text
• Language: English
• Published: The Geological Association of Canada 2021
• Subjects: climate change; flooding; fossil fuels; geological record; greenhouse effect; ice sheets; permafrost degradation; sea-level rise; geo; envir; Canada; glacier*; Ice; permafrost
• Online Access: https://doi.org/10.12789/geocanj.2021.48.173; http://id.erudit.org/iderudit/1081445ar

The Canadian Federation of Earth Sciences (CFES) has issued this statement to summarize the science, effects, and implications of climate change. We highlight the role of Earth scientists in documenting and mitigating climate change, and in managing and adapting to its consequences in Canada. CFES is the coordinated voice of Canada’s Earth Sciences community with 14 member organizations representing some 15,000 geoscientists. Our members are drawn from academia, industry, education, and government. The mission of CFES is to ensure decision makers and the public understand the contributions of Earth Science to Canadian society and the economy.Climate change has become a national and global priority for all levels of government. The geological record shows us that the global climate has changed throughout Earth’s history, but the current rates of change are almost unprecedented. Over the last 70 years, levels of common greenhouse gases (GHGs) in the atmosphere have steadily increased. Carbon dioxide (CO2) concentration is now 418 parts per million — its highest of the last three million years. The chemical (isotopic) composition of carbon in the atmosphere indicates the increase in GHGs is due to burning fossil fuels. GHGs absorb energy emitted from Earth’s surface and re-radiate it back, warming the lower levels of the atmosphere. Climatic adjustments that have recently occurred are, in practical terms, irreversible, but further change can be mitigated by lowering emissions of GHGs.Climate change is amplified by three important Earth system processes and effects. First, as the climate warms evaporation increases, raising atmospheric concentrations of water vapour, itself a GHG — and adding to warming. Second, loss of ice cover from the polar ice sheets and glaciers exposes larger areas of land and open water — leading to greater absorption of heat from the sun. Third, thawing of near-surface permafrost releases additional GHGs (primarily CO2 and methane) during decay of organic matter previously preserved frozen ...