July 2021

July 20, 2021

The evidence of climate warming is unequivocal (IPCC, 2014a, p.4). A significant source of global greenhouse gas (GHG) emissions is building construction and operations, which represent nearly 40% of total global energy use and carbon dioxide (CO₂) emissions (International Energy Agency, 2019, p. 9). This weighs heavy on me as an architect. Architects protect public safety and play a key role in shaping the built environment, but practice is not yet aligned with climate science. The following climate science primer for Canadian architects.

Canada’s Changing Climate

The scale of human generated climate change is unprecedented. The concentration of atmospheric CO₂, the primary forcing factor of climate warming, is now greater than Earth has experienced in over 800,000 years (Emanuel, 2020, p. 48). If this path continues, by 2100 we will quadruple atmospheric CO₂ equivalent over pre-industrial levels. This level has not been seen for 50 million years, a time when sea level was 70 meters higher than today, and alligators inhabited Greenland. (Emanuel, 2020, p. 29).

Canada is warming at twice the global average with the north warming fastest followed by the western provinces (Bush et al., 2019, 125). Canada’s Changing Climate Report highlights climate change to date and future projections depending on the choices we make (Bush et al., 2019). These projections are illustrated through Representative Concentration Pathways (RCPs) scenarios. By 2100 the low warming scenario under RCP2.6 forecasts an average temperature of 1.7^o Celsius over 1986-2005 (p. 6). This is the only scenario that can hold average warming to below 2^o Celsius relative to pre-industrial levels and meet the aspirational goals of the Paris Agreement (p. 6). This scenario requires significant reductions in global CO₂ emissions over the next few decades and attaining near zero annual anthropogenic CO₂ emissions by 2100 (IPCC, 2014b, p. 20). The high warming scenario under RCP8.5 forecasts an approximate 6.3^o Celsius average warming over 1986-2005 (p. 6). Under this scenario the Canadian climate and ecosystems will be unrecognizable. Such changes will impact human and ecosystem health as well as the ability of our built infrastructure to provide fundamental safety and protection.

Tools to Bridge Climate Science to Practice

Climate science can be overwhelming with its many acronyms, complex scenario graphs, and evolving models. The following are a few frameworks and tools that make it easier to bridge climate science to practice.

The RCPs provide a picture of potential climate warming pathways based on different GHG concentration scenarios. But how do we translate this to improve the resilience of buildings and their sites? The new Climate Data for a Resilient Canada website offers temperature and precipitation projections based on RCPs for Canadian cities (Climate Data for Canada, n.d.). For example, Figure 1 below highlights projected increases in ‘cooling degree days’ for Calgary based on different RCPs scenarios. This graph can be used to support a science-informed discussion on what level of warming the project should be designed for to maintain human health and comfort over a 50–80-year building lifespan.

Figure 1

Illustrates projected increases in cooling degree days for Calgary, Alberta

Note. The red line is RCP8.5 Median, green is RCP4.5 Median, blue is RCP2.6 Median, and grey is Modeled Historical. Inset boxes with degree data appear based on the year highlighted (Climate Data for a Resilient Canada, n.d., harvested July 18, 2021)

The Shared Socioeconomic Pathways (SSPs) are another helpful framework to aid climate policy planning. The SSPs offer five scenarios with narrative descriptors of possible futures. Each differ in their socioeconomic assumptions such as the rate of population growth, urbanisation, and technological development (Hausfather, (2018) What are the SPPs? section, para. 4). The socioeconomic variables help expand climate policy from an emphasis on technological change (e.g., more stringent building energy codes) to include socioeconomic change (e.g., access to education as a determinant of fertility and population growth) (E. Pond, personal communication, July 14, 2021). RCPs and SSPs provide possible trajectories to help us understand potential futures under varying conditions. When combined with a precautionary approach, these trajectories can help inform climate-responsive design.

Adaptation Versus Mitigation

Adaptation is “an adjustment in the ecological, social or economic system in response to observed or expected changes in the climatic stimuli and their effects and impacts in order to alleviate adverse impacts of change…” (IPCC (2001) as cited in Adger et al., 2005, p. 78). Architects engage in adaptation when they design projects with improved resilience to climate change and its related impacts. Adaptation also refers to the adaptative capacity of individuals, groups, and organizations (Adger et al, 2005, p. 78). The profession of architecture will itself need to adapt to maintain relevancy in a rapidly changing climate. Mitigation refers to actions taken to reduce GHG emission reductions and in turn future warming. To meet the RCP2.6 pathway, a rapid transition to net-zero carbon buildings is needed, including both operational and embodied carbon in materials.  

The built environment is a significant contributor to anthropogenic CO₂ emissions, conversely it is also a powerful pathway to mitigation of future warming and adaptation to the impacts of our changing climate. Climate scientists have provided the evidence of unprecedented levels of climate change and tools to help bridge climate science to building science. Increasing climate literacy and awareness of available tools among architects and other design professionals is a necessary step to closing the gap between the rate of climate change and the building industry’s response.

References:

Adger, W.N., Arnell, N.W., and Tompkins, E.L. (2005). Successful adaptation to climate change across scales. Global Environmental Change, 15(2), 77-86. https://doi.org/10.1016/j.gloenvcha.2004.12.005.

Bush, E., Gillett, N., Bonsal, B., Cohen, S., Derksen, C., Flato, G., Greenan, B., Shepherd, M., Zhang, X. (2019). Canada’s Changing Climate Report: Executive Summary. Government of Canada. https://changingclimate.ca/site/assets/uploads/sites/2/2019/03/CCCR_
ExecSummary.pdf

Climate Data for Canada. (n.d.). Climate data to help build a more resilient Canada V1.8 [Interactive data trends]. Retrieved July 17, 2021, from https://climatedata.ca/

Emanuel, K.A. (2020, May 15). Climate Science, Risk & Solutions. Massachusetts Institute of Technology. https://climateprimer.mit.edu/climate-science-risk-solutions-1220.pdf

Hausfather, Z. (2018). Explainer: How ‘Shared Socioeconomic Pathways’ explore future climate change. Carbon Brief. https://www.carbonbrief.org/explainer-how-shared-socioeconomic-pathways-explore-future-climate-change

Intergovernmental Panel on Climate Change. (2014a). Summary for Policy Makers:Climate Change 2014 Synthesis Report Fifth Assessment Report. https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_summary-for-policymakers.pdf  

Intergovernmental Panel on Climate Change. (2014b). Climate Change 2014: Synthesis Report https://www.ipcc.ch/site/assets/uploads/2018/02/SYR_AR5_FINAL_full.pdf

International Energy Agency and the United Nations Environment Programme. (2019). 2019 Global status report for buildings and construction: Towards a zero-emissions, efficient and resilient buildings and construction sector. https://www.ipcc.ch/site/assets/
uploads/2018/02/iphttps://www.unep.org/resources/publication/2019-global-status-report-buildings-and-construction-sector