CALS 500

August 30, 2021

The IPCC 6^th Assessment Report confirms unequivocal evidence on the magnitude and speed of climate change (IPCC, 2021, p.5) presenting unprecedented risks to ecosystems, our society, and our economy.  Vulnerable populations and Indigenous peoples are disproportionately impacted by climate change, and will bear the highest of impacts (Alston, 2019, para. 11 & Boyd, 2019, para. 48) raising significant human rights concerns. Mainstream architectural practice has not yet fully recognized the urgency of the climate crisis, the disproportionate climate impacts on the most vulnerable in society, and the necessity of design for both adaptation and mitigation.

While mitigation measures such as increasing energy efficiency are broadly understood, efforts towards low or zero carbon buildings are the exception in practice, and adaptation literacy is low. Accelerating the transition to a low-carbon and climate-resilient built environment requires enhanced literacy on climate change and its associated risks, tools to link building science and climate science, and design for climate risk adaptation and mitigation.

Canada’s Climate is Changing

Globally, the concentration of atmospheric CO₂, the primary driver of climate warming, is now greater than Earth has experienced for over 800,000 years (Emanuel, 2020, p. 48). If we continue our current emissions’ intensive growth, by 2100 we will quadruple atmospheric CO₂ equivalent over pre-industrial levels. This level of atmospheric CO₂ 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., 2019a, 125). Canada’s Changing Climate Report (Bush et al., 2019b) provides future projected warming scenarios using different Representative Concentration Pathways (RCPs). By 2100 the low warming scenario (RCP2.6) forecasts an average Canadian temperature of 1.7^o Celsius (C) over 1986-2005 (p. 6). The high warming scenario (RCP8.5) forecasts an approximate 6.3^o C 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. How then do design professions respond?

Climate Action Includes Mitigation and Adaptation

Effective climate action requires both adaptation and mitigation practices and the speed at which we reduce atmospheric greenhouse gas (GHG) emissions (mitigation) directly influences the magnitude of future climate risks and scale of adaptation necessary.

Mitigation in building design refers to actions that reduce the release of GHG emissions and in turn future warming. To hold warming to below 2^o C requires a rapid transition to net-zero carbon new and existing buildings, including both operational and embodied carbon in materials. Land use changes are the second largest driver of global warming. As we consider the embodied carbon in building materials and the land impacts of material harvesting and extraction, the importance of retrofitting existing buildings over new builds becomes much more evident.

Adaptation to climate change is defined as an “…adjustment in the ecological, social, or economic systems in response to actual or expected climatic stimuli and their effects and impacts.” (IPCC, n.d.). Architects engage in adaptation when they design projects with improved resilience to the projected future climate change and its impacts. This requires asking questions such as: how will average temperature and precipitation trends change over the lifespan of this building; what range of extreme weather events may impact this project; how will climate change impact human health and comfort, building energy use, energy and water availability, and building envelop performance; how will the design of this project anticipate these changes?  

As current building codes are based on outdated historical climate data, architects and allied design professionals must look to climate science projections to guide planning and set project design parameters. An increasing number of tools are now available to bridge climate science to building science. 

Tools to Bridge Climate Science and Building Science

The RCPs identify potential projected climate warming pathways, but how do we translate this to improve the resilience of buildings and their sites? ClimateData.ca offers temperature and precipitation projections based on the RCPs for Canadian cities (ClimateData.ca, n.d.). For example, Figure 1 below highlights projected increases in Cooling Degree Days (CDDs) for Calgary based on different RCPs scenarios. This graph can be used to support a science-informed discussion on what level of warming a project should be designed for to maintain human health and comfort over a 50–80-year building lifespan. By 2100 under a high warming scenario, Calgary may see an increase of well over 700% in CDDs from a 2005 baseline, while the low scenario estimates a 50% increase. Both scenarios are linked to significant increases in wildfire risks with resultant impacts on air quality. A precautionary approach would be to design for the high impact scenario, particularly for core health care and other social service buildings where the consequences of an inability to maintain necessary indoor air quality and temperatures are high.

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. The inset box provides Cooling Degree Day data for the selected year, in this example 2100 and a 2005  (ClimateData.ca, n.d., harvested August 30, 2021)

Low-Carbon and Climate-Resilient Buildings

Architects swear an oath to protect the public. Given the severity of climate change impacts and resultant risks to human health and human rights, architects have a direct responsibility to advance a rapid transition to a low-carbon and climate-resilient built environment. The Marrakesh Partnership provides a framework to keep global warming under 2^o C and preferably 1.5 ^o C in alignment with the Paris Agreement. Within the built environment there are two focuses areas (Marrakesh Partnership, 2021, p. 2). The first is whole-life carbon mitigation, which encompasses both operational carbon and embodied carbon in building material flows across the full life cycle from extraction through ultimate material reuse and recycling. The second is adaptation and resilience, which addresses the importance of strengthening the resilience of the built environment to chronic and acute climate change impacts.

Figure 2 demonstrates the pathway to low-carbon and climate-resilient buildings, which necessitates a focus on both whole-life carbon mitigation and design for adaptation. One without the other leaves assets and communities at risk.

The built environment is a significant contributor to anthropogenic CO₂ emissions, conversely it is also a powerful pathway to the mitigation of future warming and increased resilience to climate change impacts. 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 to integrate climate-science in building design is a key step to accelerate the transition to a low-carbon and climate-resilient built environment.

References

Alston, P. (2019). Climate change and poverty: Report of the Special Rapporteur on extreme poverty and human rights. UN Human Rights Council. https://digitallibrary.un.org/record/3883131?ln=en

Boyd, D.R. (2019). Safe Climate: A Report of the Special Rapporteur on Human Rights and the Environment. UN Human Rights, Office of the High Commissioner. Report to UN General Assembly.  https://www.ohchr.org/Documents/Issues/Environment/SREnvironment/Report.pdf

Bush, E., Gillett, N., Watson, E., Fyfe, J., Vogel, F., Swart, N. (2019a). Understanding Observed Global Climate Change; Chapter 2 in Canada’s Changing Climate Report. Government of Canada. https://changingclimate.ca/site/assets/uploads/sites/2/2020/06/CCCR_FULLREPORT-EN-FINAL.pdf

Bush, E., Gillett, N., Bonsal, B., Cohen, S., Derksen, C., Flato, G., Greenan, B., Shepherd, M., Zhang, X. (2019b). Canada’s changing climate report – Executive summary. https://changingclimate.ca/site/assets/uploads/sites/2/2019/03/CCCR_ExecSummary.pdf

Climatedata.ca. (n.d.). Climate Data for a Resilient Canada. 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

Intergovernmental Panel on Climate Change. (2021). Summary for Policymakers. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf

Intergovernmental Panel on Climate Change. (n.d.). What do adaptation to climate change and climate resilience mean? https://unfccc.int/topics/adaptation-and-resilience/the-big-picture/what-do-adaptation-to-climate-change-and-climate-resilience-mean

Marrakesh Partnership. (2021) Climate Action Pathway: Human Settlements Action Table https://unfccc.int/sites/default/files/resource/HS_ActionTable_2.1.pdf

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