WHY IS THIS WORK IMPORTANT?
A changing climate appears to be altering the fire ecology of forests and grasslands throughout the US.
Climate and ecosystem simulation models used by the United Nations Intergovernmental Panel on Climate Change (IPCC) suggest that changes in future climate may drive significant alterations of forests, shrub and grasslands and their associated fire regimes. Forest managers will be challenged by this uncertain future.
Among the challenges faced by both forest and air quality managers are increased amounts of smoke deteriorating air quality and visibility.
The paper reviews the current state of knowledge in the chain of simulation modeling being used to project these changes.
This chain includes regional climate models, ecosystem dynamics models, fuels models, fire models and air quality models. Each component model in the chain has different accuracies and uncertainties that are affected by linkages between different modeling approaches.
The JFSP Smoke Science Plan will provide estimates of changes in smoke over the 21st century. This paper provides a background to help managers evaluate and properly use these estimates.
WHAT DID WE LEARN?
The paper identifies 4 alternate pathways through the chain of models required to simulate smoke in a climate-changed future. These alternative pathways are chosen to:
- minimize cumulative errors, uncertainties and biases
- be computationally feasible
- yield transparent results
- be robust toward future projections
Each of the pathways has advantages and disadvantages that are discussed in depth.
The paper offers a few concepts to consider when selecting alternative modeling approaches.
- dynamic and coupled models are better than static and linked models
- projecting distributions is better than projecting points
- scales must match up
- keep it as simple as possible
- limit use of adjustments
- consider which uncertainties are acceptable and which are unacceptable
If the climate is changing, models are the only way to estimate of future impacts of smoke.
The paper provides background on how to interpret and potentially utilize model results from JFSP projects
that will be projecting
climate-changed future forests, fire regimes and
resulting smoke and air quality impacts.
Figure 1. Examples, from IMPROVE website, of pristine (or nearly so) vs. degraded air quality in National Parks, reflecting haze from wildland fire, other pollutants, or both. Upper panels: Yosemite National Park. Lower panels: Great Smoky Mountains National Park.
Photos courtesy of IMPROVE (http://vista.cira.colostate.edu/improve/).