By Charles “Chip” McGowan
Evaluating materials and products to meet projects’ performance requirements and code compliance is an ongoing task for specification professionals. Supporting modern construction goals, sustainable attributes, and outcomes are now part of this evaluation and specification process. Today, specifiers are increasingly being asked to examine the carbon footprint for each choice and their collective effect.
For roofing and wall cladding products, architectural zinc’s inherent metallic properties can help reduce the operational carbon footprint for residential and commercial buildings, and improve their energy-efficient, climate-resilient, long-lasting performance.
Carbon concerns and climate change
When global, national, and local governments, and other authorities having jurisdiction (AHJ) discuss reducing their carbon footprint, the inference is to reduce the effects of climate change as a result of the generation of greenhouse gases (GHGs) from various sources, including both commercial and residential construction.
To fathom the importance of lowering construction’s carbon footprint, one must grasp the extent of carbon concerns and climate change.
Carbon emissions, specifically emissions of carbon dioxide (CO2), are identified as GHGs. In conversations, the terms carbon emissions and GHG emissions are often interchangeable. In application, GHG emissions are typically measured in terms of “carbon equivalent” (CO2eq) and global warming potential (GWP). A 100-year GWP is standard, which represents the energy absorbed by a CO2eq GHG over 100 years.
CO2eq emissions absorb energy, trapping it in the atmosphere and reflecting it back as heat. The increased GHG levels and higher temperature cannot be sustained by the Earth’s natural environmental processes and are among the causes affecting the climate. These effects are demonstrated in more frequent, extreme temperature fluctuations and weather events, such as hurricanes, cyclones, tsunamis, severe storms, wildfires, droughts, and floods. Shifting patterns also result in record heat waves in formerly cold climates, and snow and hail in formerly warm climate zones. These changes have caused costly damage to critical infrastructure; disrupted food, water, and economic supply chains, and put people’s health, safety, security, and lives at risk.
According to the Canada Energy Regulator (CER), total GHG emissions in 2020 accounted for 609.7 million tonnes (672.1 million tons) of CO2eq. The geographical regions accounting for the highest emissions were:
- Alberta at 232.6 million tonnes (256.5 million tons).
- Ontario at 135.7 million tonnes (149.6 million tons)—with buildings accounting for 25.2 per cent of the province’s total emissions.
- Quebec at 69.1 million tonnes (76.24 million tons).
- Saskatchewan at 59.7 million tonnes (65.89 million tons).
- British Columbia at 56 million tonnes (61.75 million tons).
While Northwest Territories emitted only 1.198 million tonnes (1.321 million tons), buildings accounted for 23.4 per cent of its total emissions.
