UW News

April 18, 2023

Q&A: County-scale climate mapping tool helps Washington agencies prepare for the future

UW News

map of Washington colored red on right portion and around Puget Sound

The number of days when the maximum humidex surpasses 90 degrees Fahrenheit-equivalent is projected to rise by as much as 60 days per year by 2050-2079 for much of central and eastern Washington and the Puget Sound region, compared to the 1980-2009 average. This map is for a higher future greenhouse gas emissions scenario. The new tool lets users zoom in to the county level and look at projections for heat, drought, extreme precipitation, flooding, wildfire, sea level rise and reduced snowpack through 2100.University of Washington Climate Impacts Group

Many people are now aware of climate change, the need to curb greenhouse gases and to prepare for coming environmental shifts. But knowing how best to prepare can be a challenge, both for individuals and for local agencies.

The University of Washington’s Climate Impacts Group has released an interactive tool that lets state agencies and local governments see what climate scientists project for their county and what they might want to consider when developing their districts’ comprehensive plans.

The Climate Mapping for a Resilient Washington tool, released in late 2022, lets users zoom in to their county to see projections for heat, drought, extreme precipitation, flooding, wildfire, sea level rise and reduced snowpack through 2100.

UW News sat down with developer Matt Rogers, a research scientist at the UW Climate Impacts Group, to learn more about the new tool and its uses.

Q: We hear about other climate reports, like the international IPCC report or the U.S. National Climate Assessment. How does the Climate Mapping for a Resilient Washington tool fit in?

Matt Rogers: There’s not really a shortage of climate reports. But a lot of the current tools or reports have a much broader scope — they look at the entire U.S., or the whole Pacific Northwest. This particular tool focuses on Washington state, and on the information that local governments need to prepare for climate change.

I like to think of this tool as broad in scope, but not necessarily comprehensive in depth. It has a wide variety of different metrics, but it does not explore them in as much depth as our other tools. For example, this tool includes sea-level rise, but not as much information as our specific sea-level rise tool.

Q: How did this project come about?

MR: The Climate Impacts Group set out to help support climate information needs for updating the 2012 Washington State Integrated Climate Response Strategy. Based on feedback from state agencies, there was clear interest in providing local governments with the climate data, information and resources that they needed to add a climate resilience element to their comprehensive plans. This is the basic information on expected changes in the climate that local governments can use to prepare for climate change.

This tool is new for Washington state. Like the Cal-Adapt tool in California, it’s meant to give information specific to Washington state that local communities and governments can use to plan for their area — as opposed to summarizing data over the entire state.

Q: How can people use this tool?

MR: To make the tool more approachable for people who may not frequently work with climate data, we’ve included filters to cut down on the information that you’re sifting through. For example, if you’re concerned about water, you can filter to look only at climate indicators that may be particularly important for the water resources sector.

Users can select 30-year time periods from now to 2100 and choose different future emissions scenarios, depending on the trajectory for greenhouse gas emissions.

On the tool’s map you can click a specific point, and it will give you a specific number for that point. But we do want to caution people that it’s more appropriate to look over a wider region, like a county, as opposed to a particular point, which can give a false sense of precision.

Many other climate tools only include information on exposure to climate change, or how conditions are changing. This goes one step further and provides some guidance on other information that might be needed to assess climate change impacts. For example: Does your community rely on snowmelt for drinking water or irrigation? Is your population particularly vulnerable to extreme heat events? The tool provides some questions to ponder when looking at these climate indicators and using them to inform local climate resilience planning.

Q: What, generally, can Washington state expect under climate change?

MR: There’s quite a bit that I can talk about here. Snowpack definitely stands out: There’s a pretty stark reduction in projected April 1 snowpack, and an associated reduction in summer streamflows, particularly in the lower elevations of the Cascades and Olympic mountains. Those foothills are really where all the snowmelt gets funneled in the spring and summer months.

Another thing that stands out is extreme precipitation. One of the metrics we have in the tool is days with greater than 1 inch of precipitation. Some areas in Western Washington — for example along the coast and on the western slopes of the Cascades — stand out for an increase in days with precipitation greater than 1 inch.

We also have an increase in extreme heat events, both in minimum and maximum temperatures. That’s pretty consistent across the state. Areas at higher elevations will see it less, but otherwise the state is pretty consistently projected to see an increase in extreme heat events.

The last one I’ll mention is wildfires. The likelihood of climate and fuel conditions that support wildfires is projected to increase as temperatures increase, particularly east of the Cascades. But later this century there are projected increases on the west side of the Cascades, as well.

Q: Where does the data used to create these projections come from?

MR: We leveraged the knowledge and expertise of the Climate Impacts Group to compile and curate the best available regional-scale climate projections for the Pacific Northwest. Data comes from different places. For example, we used the Weather Research and Forecasting model’s downscaled hydroclimate projections developed at the UW, for extreme precipitation. We used streamflow data developed from the Columbia River Climate Change project. We use the NorWeST stream temperature dataset from the U.S. Department of Agriculture for looking at August stream temperatures.

All those datasets are downscaled. Researchers took the IPCC global climate models, which have a pretty coarse resolution of 1 degree latitude by 1 degree longitude, which doesn’t leave many data points for Washington. Then they do a statistical analysis or run a regional climate model over a smaller area to get better information over a local region.

Most of the information on this tool is downloadable — not just the information you can see or pull off the visualization, but also the underlying data. So this tool is also meant to be a resource to access regional climate data.

Q: Who do you foresee as the main audience for this tool?

MR: Our target users are mainly local government planners. Right now in Washington state agencies are encouraged, but not required, to include climate resilience elements in their comprehensive plans. However, there is a bill currently in the state legislature that would require climate resilience elements of comprehensive plans. So we could see a lot more need for this tool in the near future.

Q: It can be depressing to see these projections for more heat waves, more wildfires, less snowpack and rising seas. What can communities do with this information?

MR: This is meant to inform local governments so that communities can plan for the future. Let’s say, for example, you’re worried about salmon habitat in your particular region, and you’re curious about stream temperatures, because that has an impact on the spawning cycles of salmon and their ability to reproduce. This tool can give you information about those projected changes so you can identify whether future stream temperatures may be a problem for your area.

As another example, let’s say you’re worried about your community’s ability to respond to extreme heat events. Knowing that extreme heat events are projected to rise, and the different rates of increase in your area, can inform your preparation efforts.

We hope this tool will support efforts to prepare for climate impacts and give local governments the information they need to help preserve ecosystems and save lives.

Crystal Raymond, a climate adaptation specialist at the UW Climate Impacts Group, led the tool’s development, with additional support from the University of Idaho’s Research Data & Computing Services. Development of the tool, which is freely available, was funded by the state of Washington.


For more information, contact Rogers at rawrgers@uw.edu.