Canadian regions will experience climate change fallout differently, but a global consortium of scientists is warning residents everywhere that severe conditions and extreme events are going to be more frequent and intense. The Intergovernmental Panel on Climate Change’s (IPCC) newly delivered compendium of physical science factors and their projected outcomes is the first installment of a three-part assessment report planned for release before the end of 2022.
The report — which is the product of 234 researchers based in 66 countries and was subject to more than 78,000 expert and government review comments prior to public release — synthesizes findings from a range of scientific disciplines and draws on ongoing advancements in global and regional climate simulation to track the evolving momentum of climate change. It outlines expected impacts of 1.5-degree and 2-degree increases in the global mean temperature and details the weather-related forces most likely to be in play in regions and topographies worldwide.
“The innovations in this report, and advances in climate science that it reflects, provide an invaluable input into climate negotiations and decision-making,” says Hoesung Lee, the chair of the IPCC, which is a United Nations body, established in 1988 to provide world leaders with regularly updated scientific insight on the risks and implications of climate change.
“We now have a much clearer picture of the past, present and future climate, which is essential for understanding where we are headed, what can be done and how we can prepare,” concurs Valérie Masson-Delmotte, co-chair of the working group that produced the new report.
A “virtually certain” shift toward warmer temperatures is projected across North America, whereas current wet or dry propensities are expected to become even more pronounced. In Canada, scientists foresee accelerated warming in the far north, with attendant thawing of permafrost, glaciers and polar ice releasing vast stores of sequestered carbon that further escalates damaging trends. Western provinces are in line for harsher droughts and heightened forest fire risk, while increased precipitation spurs more river and flash flooding to the east.
Pacific and Atlantic regions will be vulnerable to a deemed “virtually certain” rise in sea level, causing more flooding in low-lying areas and more erosion, particularly along sandy shorelines. Threats to ocean ecosystems also have flow-through risks for coastal populations and key economic sectors.
For now, scientists are somewhat less definitive about changes in wind speed and related eventualities. “Tropical cyclones, severe wind and dust storms in North America are shifting toward more extreme characteristics, with a stronger signal toward heightened intensity than increased frequency, although specific regional patterns are more uncertain,” the report notes.
Meanwhile, cities are identified as the hotspots of climate change where built form, human activity and sparse vegetation combine to engender urban heat islands. Urban dwellers are expected to suffer amplified daytime temperatures and enjoy a lesser degree of nighttime cooling. They could be exposed to higher levels of air pollution due to heat-related increases in ground-level ozone, and flash flooding is likely to be more problematic as impermeable surfaces channel cascading water to lower-lying catchments. Although these trends are already well established, scientists now have “high confidence” they will worsen.
“Compared to present day, large implications are expected from the combination of future urban development and more frequent occurrence of extreme climate events, such as heatwaves, with more hot days and warm nights adding to heat stress in cities,” the report states.
“Climate change is already affecting every region on Earth in multiple ways. The changes we experience will increase with additional warming,” reiterates Panmao Zhai, co-chair of the IPCC working group.
In laying out the extent of the challenge, the scientific team seeks to bolster commitment for an aggressive response. Following this study of the physical science basis for climate change, the pending two reports in the series focus on adaptation and mitigation.
“Stabilizing the climate will require strong, rapid and sustained reductions in greenhouse gas emissions and reaching net zero CO2 emissions,” Zhai urges. “Limiting other greenhouse gases and air pollutants, especially methane, could have benefits both for health and the climate.”