Publications Library

This report provides an assessment of how climatic design data relevant to the National Building Code of Canada and the Canadian Highway Bridge Design Code might change as the climate continues to warm.

We describe in this paper a semi-parametric bivariate extreme value approach for studying rare extreme precipitation events considered as events that result from a combination of extreme precipitable water (PW) in the atmospheric column above the location where the event occurred and extreme precipitation efficiency, described as the ratio between precipitation and PW. An application of this framework to historical 6-h precipitation accumulations simulated by the Canadian Regional Climate Model CanRCM4 shows that uncertainties and biases of very long-period return level estimates can be substantially reduced relative to the standard univariate approach that fits Generalized Extreme Value distributions to samples of annual maxima of extreme precipitation even when using modest amounts of data.

This is the November 2020 issue of the PCIC Update. It includes the following stories: A Preview of Winter? A Record Wet and Cool Spring and Summer in BC; Studying how Changing Precipitation May Affect Landslides in BC; Supporting BC Salmon Management; PCIC Corporate Report Released and Vancouver Island Agriculture Planning Report Released. This issue's staff profile is on Dr. Md. Shahabul Alam. The issue concludes with the PCIC staff news and a list of recent publications by PCIC researchers.

This report places the conditions in British Columbia (BC) over 2019 into climatological context. It finds that: a moderate El Niño likely contributed to a slightly warmer than normal 2019 in BC; anomalous warmth peaked in spring, forcing rapid melt of a near-normal winter snowpack; precipitation in summer and fall was above-to-much-above normal across the province; trends in temperature are positive for the period 1950 – 2019 with minimum temperatures (Tmin) increasing faster than maximum temperatures (Tmax), and that precipitation shows no significant trend over the same period.

Background 
Food- and water-borne pathogens exhibit spatial heterogeneity, but attribution to specific environmental processes is lacking while anthropogenic climate change alters these processes. The goal of this study was to investigate ecology, land-use and health associations of these pathogens and to make future disease projections. 

Methods
The rates of five acute gastrointestinal illnesses (AGIs) (campylobacteriosis, Verotoxin- producing Escherichia coli, salmonellosis, giardiasis and cryptosporidiosis) from 2000 to 2013 in British Columbia, Canada, were calculated across three environmental variables: ecological zone, land use, and aquifer type. A correlation analysis investigated relationships between 19 climatic factors and AGI. Mean annual temperature at the ecological zone scale was used in a univariate regression model to calculate annual relative AGI risk per 1 °C increase. Future cases attributable to climate change were estimated into the 2080s.

Findings
Each of the bacterial AGI rates was correlated with several annual temperature-related factors while the protozoan AGIs were not. In the regression model, combined relative risk for the three bacterial AGIs was 1.1 [95% CI: 1.02–1.21] for every 1 °C in mean annual temperature. Campylobacteriosis, salmonellosis and giardiasis rates were significantly higher (p < 0.05) in the urban land use class than in the rural one. In rural areas, bacteria and protozoan AGIs had significantly higher rates in the unconsolidated aquifers. Verotoxin-producing Escherichia coli rates were significantly higher in watersheds with more agricultural land, while rates of campylobacteriosis, salmonellosis and giardiasis were significantly lower in agricultural watersheds. Ecological zones with higher bacterial AGI rates were generally projected to expand in range by the 2080s.

Interpretation
These findings suggest that risk of AGI can vary across ecosystem, land use and aquifer type, and that warming temperatures may be associated with an increased risk of food-borne AGI. In addition, spatial patterns of these diseases are projected to shift under climate change.

Cold climate regions offer various ecosystem services. The water quality parameters such as dissolved oxygen (DO), water temperature (Tw), and dissolved organic carbon (DOC) have considerable impacts on the aquatic ecosystem species. Any impairments in water quality such as elevated water temperature, and low DO concentrations can limit the survival of aquatic ecosystems and its species, such as walleye, northern pike and salmon. Therefore, a good understanding of the aquatic ecosystem of rivers is essential for effective and sustainable river basin and watershed management of fisheries and aquatic resources. The objectives of this study is to improve a watershed scale module of water quality (DO, DOC and Fecal coliforms (FC) in the SWAT model to examine the spatiotemporal patterns and their impacts on aquatic ecosystem and water quality processes in the Athabasca River Basin (ARB), Alberta, Canada. The calibration and validation results of DO, DOC and FC show that the improved Soil and Water Assessment Tool (SWAT) model achieved successfully with a varied range (satisfactory to vey-good) of accuracy at the daily temporal scales. The results showed that concentrations of DO for the selected stations (spring and summer) reduced far below the thresholds for ecosystems survival. In concurrent reduction with DO, the FC concentration considerably varied in the different monitoring stations of ARB. These results highlight that DO, DOC and FC variability in the ARB may drive changes in water quality and ecosystem services that have to be understood on the specific research scale for designing adaptive management scenarios. This study reveals that the new SWAT model can be applied to other similar regions of the worlds.

The primary objective of this study is to assess the implications of increasing outdoor air
temperatures due to climate change on the thermal comfort of multifamily residential
buildings in the Lower Mainland, and to identify cost-effective design measures that will
maintain thermal comfort under future climate conditions.

A variety of climate adaptation and mitigation measures (CAMMs) suitable for both new
and existing, high and low rise multifamily residential buildings are explored using future
climate projections. Ideally, solutions are identified that improve thermal comfort without
sacrificing parallel societal objectives to reduce energy consumption and greenhouse gas
emissions. It is also desirable that identified solutions improve the resiliency of buildings
to maintain comfort during increasingly common extreme weather events such as
unusually high temperatures, wildfire-induced poor air quality, or power outages.

The results of this study will support development of design guidelines, policies and
standards that ensure new building provide residents with thermally comfortable
environments, as well as programs that improve the thermal comfort of existing
residential buildings. This study will also guide best practises for incorporating
projections of warmer future climate conditions into building energy modelling and
design.

Understanding and quantifying the global methane (CH4) budget is important for assessing realistic pathways to mitigate climate change. Atmospheric emissions and concentrations of CH4 continue to increase, making CH4 the second most important human-influenced greenhouse gas in terms of climate forcing, after carbon dioxide (CO2). The relative importance of CH4 compared to CO2 depends on its shorter atmospheric lifetime, stronger warming potential, and variations in atmospheric growth rate over the past decade, the causes of which are still debated. Two major challenges in reducing uncertainties in the atmospheric growth rate arise from the variety of geographically overlapping CH4 sources and from the destruction of CH4 by short-lived hydroxyl radicals (OH). To address these challenges, we have established a consortium of multidisciplinary scientists under the umbrella of the Global Carbon Project to synthesize and stimulate new research aimed at improving and regularly updating the global methane budget. Following Saunois et al. (2016), we present here the second version of the living review paper dedicated to the decadal methane budget, integrating results of top-down studies (atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up estimates (including process-based models for estimating land surface emissions and atmospheric chemistry, inventories of anthropogenic emissions, and data-driven extrapolations).

For the 2008–2017 decade, global methane emissions are estimated by atmospheric inversions (a top-down approach) to be 576 Tg CH4 yr−1 (range 550–594, corresponding to the minimum and maximum estimates of the model ensemble). Of this total, 359 Tg CH4 yr−1 or ∼ 60 % is attributed to anthropogenic sources, that is emissions caused by direct human activity (i.e. anthropogenic emissions; range 336–376 Tg CH4 yr−1 or 50 %–65 %). The mean annual total emission for the new decade (2008–2017) is 29 Tg CH4 yr−1 larger than our estimate for the previous decade (2000–2009), and 24 Tg CH4 yr−1 larger than the one reported in the previous budget for 2003–2012 (Saunois et al., 2016). Since 2012, global CH4 emissions have been tracking the warmest scenarios assessed by the Intergovernmental Panel on Climate Change. Bottom-up methods suggest almost 30 % larger global emissions (737 Tg CH4 yr−1, range 594–881) than top-down inversion methods. Indeed, bottom-up estimates for natural sources such as natural wetlands, other inland water systems, and geological sources are higher than top-down estimates. The atmospheric constraints on the top-down budget suggest that at least some of these bottom-up emissions are overestimated. The latitudinal distribution of atmospheric observation-based emissions indicates a predominance of tropical emissions (∼ 65 % of the global budget,

Some of our global source estimates are smaller than those in previously published budgets (Saunois et al., 2016; Kirschke et al., 2013). In particular wetland emissions are about 35 Tg CH4 yr−1 lower due to improved partition wetlands and other inland waters. Emissions from geological sources and wild animals are also found to be smaller by 7 Tg CH4 yr−1 by 8 Tg CH4 yr−1, respectively. However, the overall discrepancy between bottom-up and top-down estimates has been reduced by only 5 % compared to Saunois et al. (2016), due to a higher estimate of emissions from inland waters, highlighting the need for more detailed research on emissions factors. Priorities for improving the methane budget include (i) a global, high-resolution map of water-saturated soils and inundated areas emitting methane based on a robust classification of different types of emitting habitats; (ii) further development of process-based models for inland-water emissions; (iii) intensification of methane observations at local scales (e.g., FLUXNET-CH4 measurements) and urban-scale monitoring to constrain bottom-up land surface models, and at regional scales (surface networks and satellites) to constrain atmospheric inversions; (iv) improvements of transport models and the representation of photochemical sinks in top-down inversions; and (v) development of a 3D variational inversion system using isotopic and/or co-emitted species such as ethane to improve source partitioning.

The data presented here can be downloaded from https://doi.org/10.18160/GCP-CH4-2019 (Saunois et al., 2020) and from the Global Carbon Project.

The oil sands industry in Canada uses soil–vegetation–atmosphere-transfer (SVAT) water balance models, calibrated against short-term (less than 10 years) field monitoring data, to evaluate long-term (≈60 years) reclamation cover design performance. These evaluations use long-term historical climate data; however, the effects of climate change should also be incorporated in these analyses. Although statistical downscaling of global climate change projections is commonly used to obtain local, site-specific climate, high resolution dynamical downscaling can also be used. The value of this latter approach to obtain local site-specific projections for mine reclamation covers has not been evaluated previously. This study explored the differences in key water balance components of three reclamation covers and three natural sites in northern Alberta, Canada, under future, site-specific, statistical, and dynamical climate change projections. Historical meteorological records were used to establish baseline periods. Temperature datasets were used to calculate potential evapotranspiration (PET) using the Hargreaves–Samani method. Statistical downscaling uses the Long Ashton Research Station Weather Generator (LARS-WG) and global circulation model (GCM) projections of temperature and precipitation. Dynamical climate change projections were generated on a 4 km grid using the weather research and forecasting (WRF) model. These climate projections were applied to a physically-based water balance model (i.e. Hydrus-1D) to simulate actual evapotranspiration (AET) and net percolation (NP) for the baseline and future periods. The key findings were: (a) LARS-WG outperformed WRF in simulating baseline temperatures and precipitation; (b) both downscaling methods showed similar directional shifts in the future temperatures and precipitation; (c) this, in turn, created similar directional shifts in future growing season median AET and NP, although the increase in future NP for LARS-WG was higher than that for WRF. The relative increases in future NP were much higher than the relative increases in future AET, particularly for the reclamation covers.