ClimateData.ca adds updated Relative Sea-Level Change and new Vertical Allowance data

What’s New?

ClimateData.ca has been updated with two marine datasets: Relative Sea-Level Change (RSLC), updated to CMIP6, and a new Vertical Allowance dataset. These datasets provide information to support coastal adaptation planning, infrastructure design, and risk assessments in response to climate change-driven sea-level change.

Background

Canada’s coastline is increasingly exposed to the impacts of climate change, including rising sea levels and extreme water-level events. To aid coastal planners, engineers, and decision-makers, ClimateData.ca now provides access to two complementary datasets:

  • Relative Sea-Level Change (RSLC) dataset: This dataset integrates global sea-level rise projections with local vertical land motion data to deliver high-resolution estimates of relative sea-level change along Canada’s coastlines. Derived from CMIP6 global climate models, these projections are an updated version of a previous dataset on ClimateData.ca (CMIP5 Relative Sea-Level Change). The CMIP5 dataset will remain available for comparison.

  • Vertical Allowances dataset: This dataset provides recommended elevations to be added to infrastructure design based on historical and projected future water levels. It integrates relative sea-level change projections, local tide and storm surge characteristics, and associated uncertainties to support flood risk assessments and infrastructure resilience planning.

Note: The vertical allowance dataset provides general guidance at a national scale, but does not replace the need for local projections or risk assessments, particularly when planning for critical infrastructure or site-specific developments. It is best used as a complement to more detailed local data, where available.

Why are these datasets important?

Accurate and location-specific sea-level change data is essential for developing effective adaptation strategies. The Vertical Allowances Dataset helps determine how much an asset, such as a hospital, pier, or house, should be elevated to maintain an acceptable probability of flooding over its design lifetime. Meanwhile, the RSLC Dataset allows users to explore site-specific relative sea-level projections and understand how changes vary across Canada due to regional factors such as vertical land motion, ocean currents, and gravitational effects.

These datasets are particularly valuable for:

  • Coastal planners and engineers developing resilient infrastructure designs
  • Emergency management professionals assessing coastal flooding risk
  • Municipal, provincial, territorial and Indigenous governments integrating climate projections into policy
  • Researchers studying the impacts of sea-level change on Canada’s coastal ecosystems and communities

It should be noted that the crustal velocity model used for the Relative Sea-Level Change data available on ClimateData.ca is based on measurements of land motion made on bedrock. Therefore, local subsidence and compaction effects in locations with a thick sequence of unconsolidated sediment, i.e. large deltas such as those at the mouth of the Fraser and Mackenzie rivers (James et al, 2021), are not reflected in the crustal velocity model. Consequently, the sea-level projections in such locations should be adjusted to incorporate, if available, local knowledge of vertical land motions. For this reason, the Vertical Land Motion data from the crustal velocity model used for this dataset is provided. This will allow users to remove the effects of vertical land motions as calculated in the crustal velocity model from the sea level data found on ClimateData.ca with a view to replace it with values based on other sources of local knowledge of vertical land motion.

Rollout and Availability

  • Relative Sea-Level Change Dataset Interactive Map: Access Relative Sea-Level Change projections and understand regional variations.
  • Vertical Allowances Dataset Interactive Map: Explore Vertical Allowances projections across Canada’s coastal regions.

 

For more information on how to use these datasets and incorporate them into adaptation planning, contact the Climate Services Support Desk for assistance.