Environmental Change

The Earth's climate is continuously changing and has always changed through time. These changes are based on complex, oscillating cycles that occur on decadal, century, and millennial time scales. Climate shifts are common, marked by ice ages as well as long warming periods.

There is evidence that human activities have altered natural climatic cycles. Over the past several hundred years, the composition of the atmosphere has been altered in a novel way by fossil fuels combustion (e.g., coal, oil, natural gas). Heat-trapping concentrations of "greenhouse gas" have increased significantly. The major greenhouse gas contributed to the atmosphere by human activities is CO₂, but also includes CH₄, NO_x, and tropospheric O₃. Given the natural variability of the Earth's climate, it is difficult to determine the current and future increase in greenhouse gas buildup, and subsequent effects on air temperature and realized water availability to plants, which may increase or decrease depending on global air flow and topography.

In computer-based models, rising concentrations of greenhouse gases generally produce an increase in temperature and instabilities in weather. Because every component of ecosystems responds to temperature and water, current ecosystems are and will continue to change in response to increases in global temperature and dynamic water supply. Evidence for climate change has already been reported in thousands of publications, in locations thoroughly distributed around the globe. These changes, as well as predicted future changes, differ considerably from place to place. Therefore each region of the West will experience site-specific changes in temperature, precipitation, and their timing within each year. Because the nature of wildlands in these regions also differ, management actions will differ widely to account for those differing climate changes and effects.

Current WWETAC Environmental Change Projects:

• Biophysical limitations, migration potential, and climatic ranges of tree species in the interface between the boreal forest and the temperate rainforest in Alaska: an information synthesis
  
• Long-term carbon dynamics in aridland ecosystems
• Review of vulnerability assessments and Southwest vulnerability to climate change

Past WWETAC Environmental Change Projects:

• Adapting and improving Swiss needle cast management tools to incorporate climate change projections
• Adapting to Climate Change- A Short Course for Land Managers
• Annotated Bibliography of Climate and Bark Beetles of Western Forests
• Applied resistance breeding for forest trees workshop
• An assessment of climate change impacts and adaptation options for National Forest genetic resources
• Climate Change and Forest Diseases in the West - An Information Synthesis
• Climate Change Effects in the Pacific Northwest on the Future Dynamics of the Gypsy Moth
• Climate Change Toolkit
• Downscaling Meteorological Datasets for Climate Change Assessments
• Exploring Quantitative Approaches for Vegetation Management and Forest Planning Under a Changing Climate—Workshop
• Forests, Insects and Pathogens, and Climate Change Workshop, June 26-28, 2007, Portland, OR
• Landscape-scale enhanced mountain pine beetle and climate change threat assessment
• Method Development and Application for Linking VDDT and MC1: Climatizing State-and-Transition Models
• Potential interactions with forest insects and fire activity
• Rapid Threat Assessment of Climate Change Effects on Western Bark Beetles
• Vegetation and Climate Change Modeling Shortcourse
• Vegetation Models and Climate Change Workshop– January 23-25, 2008,Portland, Oregon
• Westwide Climate Change Initiative
• Wildfire links to climate change: Linking FlamMap wildfire simulation model to the Envision planning model