Informing BC Stakeholders

You are here

Publications Library

  • Authors: The Pacific Climate Impacts Consortium Publication Date: Apr 2024

    The Earth’s climate system is warming, and signs of climate change are becoming evident across the planet. The capital region, located on Southern Vancouver Island and Gulf Islands of British Columbia (BC), is no exception. The Capital Regional District (CRD) has partnered with the Pacific Climate Impacts Consortium (PCIC) to produce high-resolution regional projections for temperature, precipitation, and related indices of extremes. These projections use the most up-to-date global modeling data (i.e., the Sixth Coupled Model Intercomparison Project, CMIP6) to illustrate how the region’s climate may change by the middle of this century. Information provided by this report and the accompanying data is intended to support decision makers and community partners in the region with an improved understanding of projected local climate change and related impacts.

  • Authors: The Pacific Climate Impacts Consortium Publication Date: Feb 2024

    This edition of the PCIC Update contains the following stories: New PCIC Director Featured in UVic News, City of Vancouver Climate Report Released, PCIC’s Evolution Over the Past 15 Years: A Retrospective by Rachel Goldsworthy and Supporting Risk Assessments in BC, along with updates on staff changes and the Pacific Climate Seminar Series. The staff issue in this profile is on Markus Schnorbus.

  • Authors: The Pacific Climate Impacts Consortium Publication Date: Nov 2023

    The Earth’s climate system—atmosphere, land, ocean and the ecosystems they support—is changing in response to increasing concentrations of greenhouse gases and various pollutants in the atmosphere from ongoing industrial development. The increase in global mean temperature in recent decades has been unequivocally established and attributed to these anthropogenic drivers, and similar changes are being detected in key climate variables on con8nental scales. Recent historical temperature change in British Columbia is also emerging from the noise of climate variability, and future projections indicate this trend will contonue without significant cuts in carbon emissions. The regional and local manifestations of global climate change need to be studied and monitored, in order to design appropriate responses and adaptations.

    Like other major cities worldwide, the City of Vancouver requires up-to-date, science-based, spatially resolved information to enable effective planning and policy decisions. This short report summarizes the data produced by the Pacific Climate Impacts Consortium delivered as part of this project. We hope that it will be helpful as a stepping stone for the City as it develops plans and effective responses to these upcoming challenges.

  • Authors: The Pacific Climate Impacts Consortium Publication Date: Oct 2023

    This is the Pacific Climate Impacts Consortium's 2022-2023 Corporate Report.

  • Authors: The Pacific Climate Impacts Consortium Publication Date: Sep 2023

    This issue of the PCIC Update contains the following stories: Data Portal for Canada’s Western Arctic Released, Supporting the Management of BC Salmon Habitats and New Future-Adjusted Weather Files for Canada. It also contains an update on the Pacific Climate Seminar Series, staff changes at PCIC and PCIC's most recent publications. The staff profile in this issue is on Eric Yvorchuk.

  • Source Publication: Hydrology and Earth System Sciences, 27, 3241–3263, doi:10.5194/hess-27-3241-2023 Authors: Larabi, S., J. Mai, M. Schnorbus, B.A. Tolson and F. Zwiers Publication Date: Sep 2023

    Land surface models have many parameters that have a spatially variable impact on model outputs. In applying these models, sensitivity analysis (SA) is sometimes performed as an initial step to select calibration parameters. As these models are applied to large domains, performing sensitivity analysis across the domain is computationally prohibitive. Here, using a Variable Infiltration Capacity model (VIC) deployment to a large domain as an example, we show that watershed classification based on climatic attributes and vegetation land cover helps to identify the spatial pattern of parameter sensitivity within the domain at a reduced cost. We evaluate the sensitivity of 44 VIC model parameters with regard to streamflow, evapotranspiration and snow water equivalent over 25 basins with a median size of 5078 km2. Basins are clustered based on their climatic and land cover attributes. Performance in transferring parameter sensitivity between basins of the same cluster is evaluated by the F1 score. Results show that two donor basins per cluster are sufficient to correctly identify sensitive parameters in a target basin, with F1 scores ranging between 0.66 (evapotranspiration) and 1 (snow water equivalent). While climatic attributes are sufficient to identify sensitive parameters for streamflow and evapotranspiration, including the vegetation class significantly improves skill in identifying sensitive parameters for the snow water equivalent. This work reveals that there is opportunity to leverage climate and land cover attributes to greatly increase the efficiency of parameter sensitivity analysis and facilitate more rapid deployment of land surface models over large spatial domains.

  • Authors: C.L. Curry, D. Ouali, S.R. Sobie and F.W. Zwiers Publication Date: Jul 2023

    This report outlines a method for selecting a subset of earth system models (ESMs) from the Sixth Coupled Model Intercomparison Project (CMIP6) that is sufficiently representative of an ensemble of 26 models from CMIP6 for Canada and its subregions. The specific objective is to obtain a subset of reasonably independent ESMs that captures the overall range of projected change in a representative set of climate extremes (ETCCDI or Climdex) indices constructed from the ESM outputs. Projections are calculated for a future epoch corresponding to a global mean temperature change of 2 ℃ relative to 1971-2000, using results from two of the CMIP6 Shared Socioeconomic Pathways (SSPs), SSP2-4.5, and SSP5-8.5. The selection procedure is described below and representative subsets are provided for Canada and five of its subregions.

  • Authors: The Pacific Climate Impacts Consortium Publication Date: Jun 2023

    This Science Brief covers a paper published in Nature Climate Change that uses reanalysis data to examine extreme fire weather and the conditions that drive it over the 1979-2020 period. The paper shows that temperature and relative humidity are driving observed global trends of increased fire weather. In this Science Brief we discuss what these results tell us about changes to fire weather in our province and across Canada.

  • Authors: The Pacific Climate Impacts Consortium Publication Date: Jun 2023

    This issue of the PCIC Update contains the following stories: Climate Projections for the City of Terrace Released and A Mystery Gremlin Resolved! It also contains an update on the Pacific Climate Seminar Series, staff changes at PCIC and PCIC's most recent publications. The staff profile in this issue is on Tom Kunkel.

  • Source Publication: Environmental Modelling & Software, 163, 105682, doi:10.1016/j.envsoft.2023.105682 Authors: Souaissi, Z, T.B. Ouarda, A. St-Hilaire and D. Ouali Publication Date: Jun 2023

    Improve the estimation of water temperature extremes at ungauged sites.
    Incorporate non-linearities in the homogenous region delineation step using NLCCA.
    Consider non-linear models in the whole estimation procedure (NLCCA + GAM).
    Compare fully and partially non-linear approaches for water temperature regionalization.
    The results underline the importance of considering the non-linearity of thermal processes.

  • Source Publication: Environmental Science and Technology, 57, 19, 7401–7409, doi:10.1021/acs.est.2c08243 Authors: Lao, I.R., A. Feinberg, and N. Borduas-Dedekind Publication Date: Jun 2023

    Selenium (Se) is an essential nutrient for humans and enters our food chain through bioavailable Se in soil. Atmospheric deposition is a major source of Se to soils, driving the need to investigate the sources and sinks of atmospheric Se. Here, we used Se concentrations from PM2.5 data at 82 sites from 1988 to 2010 from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network in the US to identify the sources and sinks of particulate Se. We identified 6 distinct seasonal profiles of atmospheric Se, grouped by geographical location: West, Southwest, Midwest, Southeast, Northeast, and North Northeast. Across most of the regions, coal combustion is the largest Se source, with a terrestrial source dominating in the West. We also found evidence for gas-to-particle partitioning in the wintertime in the Northeast. Wet deposition is an important sink of particulate Se, as determined by Se/PM2.5 ratios. The Se concentrations from the IMPROVE network compare well to modeled output from a global chemistry-climate model, SOCOL-AER, except in the Southeast US. Our analysis constrains the sources and sinks of atmospheric Se, thereby improving the predictions of Se distribution under climate change.

  • Authors: The Pacific Climate Impacts Consortium Publication Date: Jun 2023

    One of the key uncertainties in climate model simulations has to do with the response of low-lying marine clouds to increasing temperatures. A recent paper in the journal Nature uses a mix of radar, lidar and data from atmospheric probes to test one of the mechanisms by which cloud cover is projected to be reduced under climate change. Their findings show that this mechanism is not evident in the trade wind regions, which suggests that might not occur in nature. This further suggests that the most extreme estimates of the climate's response to greenhouse gas emissions are less likely than earlier research suggests. Here we discuss what these results tell us about changes to the Earth's sensitivity to greenhouse gas emissions and what this may mean for our province.

  • Source Publication: Journal of Climate, Early Online Access, doi:10.1175/JCLI-D-22-0713.1 Authors: Sun, Q. F.W. Zwiers, X. Zhang and Y. Tan Publication Date: Jun 2023

    El Niño–Southern Oscillation (ENSO) has a profound influence on the occurrence of extreme precipitation events at local and regional scales in the present-day climate, and thus it is important to understand how that influence may change under future global warming. We consider this question using the large-ensemble simulations of CESM2, which simulates ENSO well historically. CESM2 projects that the influence of ENSO on extreme precipitation will strengthen further under the SSP3–7.0 scenario in most regions whose extreme precipitation regimes are strongly affected by ENSO in the boreal cold season. Extreme precipitation in the boreal cold season that exceeds historical thresholds is projected to become more common throughout the ENSO cycle. The difference in the intensity of extreme precipitation events that occur under El Niño and La Niña conditions will increase, resulting in “more extreme and more variable hydroclimate extremes.” We also consider the processes that affect the future intensity of extreme precipitation and how it varies with the ENSO cycle by partitioning changes into thermodynamic and dynamic components. The thermodynamic component, which reflects increases in atmospheric moisture content, results in a relatively uniform intensification of ENSO-driven extreme precipitation variation. In contrast, the dynamic component, which reflects changes in vertical motion, produces a strong regional difference in the response to forcing. In some regions, this component amplifies the thermodynamic-induced changes, while in others, it offsets them or even results in reduction in extreme precipitation variation.

  • Authors: City of Terrace, The Pacific Climate Impacts Consortium, Pinna Sustainability Publication Date: May 2023

    The Climate Projections for the City of Terrace report provides projections and impacts analysis for the City of Terrace, BC and is intended to support decision making throughout the region and to help community partners better understand how their work may be affected by the changing climate

  • Source Publication: International Journal of Climatology, 43, 2, 837– 849, doi: 10.1002/joc.7833 Authors: Diaconescu, E., H. Sankare, K. Chow, T.Q. Murdock and A.J. Cannon Publication Date: Apr 2023

    The projected increase in the frequency and intensity of extreme heat events due to climate change means an associated increase in risk of heat-related illnesses and mortality. Public health systems need to be prepared to identify and reduce the susceptibility of vulnerable populations to increased occurrence of heat-related illness and stress. To facilitate this, climate services have begun developing climate change projections for heat-stress indices based on exceedances of thresholds used operationally in meteorological heat warning systems. This task is complicated by the fact that heat-stress indices are generally computed using hourly data whereas climate model outputs are often archived at daily or longer time steps. This study focuses on Humidex, a heat-stress index used in heat alerts issued by the Meteorological Service of Canada. Several potential solutions for computing robust Humidex indices using daily data are examined, including a new approximation method. Indices obtained with the new method are compared with indices obtained using the classic method based on hourly data as well as with other two methods based on average daily values. The new approximation gives good estimations for humidex indices, while the daily-average-value methods present biases with respect to the hourly-value method.

  • Source Publication: Journal of Hydrology X, 17, 100144, doi:10.1016/j.hydroa.2022.100144 Authors: Tsuruta, K. and M. A. Schnorbus Publication Date: Apr 2023

    As glaciers across the world continue to recede, there is a concern that their loss as a fresh water reservoir within mountainous basins will have a negative impact on stream temperatures and downstream water resources. Currently, there are relatively few glacio-hydrological models (GHMs) appropriate to study such phenomena and studies that have used GHMs generally acknowledge the high uncertainty associated with their simulations. Calibration techniques present a particular issue in GHMs as available glacier observations are limited and errors in the glacierized portion of a basin can be compensated by errors in the non-glacierized portion. Using as a study site the Cheakamus Basin in British Columbia, Canada, we 1) present a new, fully-coupled GHM, 2) analyze the effects different calibration techniques have on the model’s summer streamflow projections, and 3) compare the fully-coupled GHM results to projections using a one-way GHM. The calibration techniques studied vary in terms of glacier representation (dynamic/static), and glacier constraint (mass balance/thinning rates/thinning rates and area change). We find projected future climate forcings are sufficiently strong in the Cheakamus Basin so as to generally make the sign and significance of changes to the basin’s hydrology insensitive to the calibration and projection procedures studied. However, the variation among these procedures produces significant changes in the projected magnitude of future hydrological changes and therefore should be carefully considered in studies where precision beyond the sign and significance of change is required. Based on analysis of the variation within each procedure’s set of model outputs, we conclude 1) the two-way GHM has benefits over the one-way model, 2) calibration using dynamic glaciers and a thinning rate constraint is preferable for the new GHM, and 3) there is a need for additional studies on the uncertainties associated with the calibration of glacio-hydrological models.

  • Authors: The Pacific Climate Impacts Consortium Publication Date: Apr 2023

    This issue of the PCIC Update contains the following stories: Correcting CMIP6 Model Output for Downscaling, Bilingual Design Value Explorer Announcement, and IPCC Summary for Policy Makers on Synthesis Report. It also contains an update on the Pacific Climate Seminar Series, staff changes at PCIC and PCIC's most recent publications. The staff profile in this issue is on Nina Nichols.

  • Source Publication: Earth System Dynamics, 13, 1689–1713, doi:10.5194/esd-13-1689-2022 Authors: Philip, S. Y., S.F. Kew, G.J. van Oldenborgh, F.S. Anslow, S.I. Seneviratne, R. Vautard, D. Coumou, K.L. Ebi, J. Arrighi, R. Singh, M. van Aalst, C. Pereira Marghidan, M. Wehner, W. Yang, S. Li, D.L. Schumacher, M. Hauser, R. Bonnet, L.N. Luu, F. Lehner, Publication Date: Apr 2023

    Towards the end of June 2021, temperature records were broken by several degrees Celsius in several cities in the Pacific Northwest areas of the US and Canada, leading to spikes in sudden deaths and sharp increases in emergency calls and hospital visits for heat-related illnesses. Here we present a multi-model, multi-method attribution analysis to investigate the extent to which human-induced climate change has influenced the probability and intensity of extreme heat waves in this region. Based on observations, modelling and a classical statistical approach, the occurrence of a heat wave defined as the maximum daily temperature (TXx) observed in the area 45–52∘ N, 119–123∘ W, was found to be virtually impossible without human-caused climate change. The observed temperatures were so extreme that they lay far outside the range of historical temperature observations. This makes it hard to state with confidence how rare the event was. Using a statistical analysis that assumes that the heat wave is part of the same distribution as previous heat waves in this region led to a first-order estimation of the event frequency of the order of once in 1000 years under current climate conditions. Using this assumption and combining the results from the analysis of climate models and weather observations, we found that such a heat wave event would be at least 150 times less common without human-induced climate change. Also, this heat wave was about 2 ∘C hotter than a 1-in-1000-year heat wave would have been in 1850–1900, when global mean temperatures were 1.2 ∘C cooler than today. Looking into the future, in a world with 2 ∘C of global warming (0.8 ∘C warmer than today), a 1000-year event would be another degree hotter. Our results provide a strong warning: our rapidly warming climate is bringing us into uncharted territory with significant consequences for health, well-being and livelihoods. Adaptation and mitigation are urgently needed to prepare societies for a very different future.

  • Source Publication: Journal of Applied Meteorology and Climatology, 61, 9, doi:10.1175/JAMC-D-21-0205.1 Authors: Lao, I.R., C. Abraham, E. Wiebe, and A.H. Monahan Publication Date: Apr 2023

    Nocturnal warming events (NWEs) are abrupt interruptions in the typical cooling of surface temperatures at night. Using temperature time series from the high-resolution Vancouver Island School-Based Weather Station Network (VWSN) in British Columbia, Canada, we investigate temporal and spatial characteristics of NWEs. In this coastal region, NWEs are more frequently detected in winter than in summer, with a seasonal shift from slowly warming NWEs dominating the winter months to rapidly warming NWEs dominating the summer months. Slow-warming NWEs are of relatively small amplitude and exhibit slow cooling rates after the temperature peaks. In contrast, fast-warming NWEs have a temperature increase of several kelvins with shorter-duration temperature peaks. The median behavior of these distinct NWE classes at individual stations is similar across the entire set of stations. The spatial synchronicity of NWEs across the VWSN (determined by requiring NWEs at station pairs to occur within given time windows) decreases with distance, including substantial variability at nearby stations that reflects local influences. Fast-warming NWEs are observed to occur either simultaneously across a number of stations or in isolation at one station. Spatial synchronicity values are used to construct undirected networks to investigate spatial connectivity structures of NWEs. We find that, independent of individual seasons or NWE classes, the networks are largely unstructured, with no clear spatial connectivity structures related to local topography or direction.

  • Source Publication: Journal of Hydrology: Regional Studies, 44, 101237, doi:10.1016/j.ejrh.2022.101237 Authors: Larabi, S., M. A. Schnorbus, and F. Zwiers Publication Date: Dec 2022

    Study region:
    Nechako Reservoir, British Columbia, Canada.

    Study focus:
    Hydrological regulation affect both hydrological and thermal conditions in the reservoir and downstream reach, subsequently disrupting fish habitats. This paper aims at developing an integrated model simulating physical processes that govern the quantity and quality of inflow, reservoir, and outflow water of the Nechako Reservoir. Such a model would help stakeholders understand the response of in-reservoir water temperature stratification and downstream water temperature to changes in inflow and reservoir operation under future climate change.

    New hydrological insights for the region:
    The model was calibrated against historical reservoir levels and in-reservoir and outlet water temperature field data. The integrated model simulated accurately the wide variation of reservoir levels as well as the in-reservoir water temperature at Kenney Dam and the outlet temperature. Sensitivity analysis shows that reservoir water temperature particularly the epilimnion is sensitive to changes in both meteorological and hydrological forcing. Forcing the model with different outflow scenarios shows the weak sensitivity of temperature of water released to outflow rates. Given epilimnion water releases at the spillway, the Summer Temperature Management Program could be inefficient to provide cool water in the Nechako River during the critical period of salmon migration in a warming climate. However, colder water remains available at depth at Kenney Dam to potentially mitigate and better control downstream water temperature.