2014 U.S. Climate Action Report to the UNFCC

The State Department’s 2014 U.S. Climate Action Report details actions that the U.S. is taking domestically and internationally to address climate change.

A Risk Assessment of Climate Change and the Impact of Forest Diseases on Forest Ecosystems in the Western United States and Canada

A Risk Assessment of Climate Change and the Impact of Forest Diseases projects the effects of eight forest diseases under two climate-change scenarios. Examples are used to describe how various types of forest diseases may respond to environmental changes with a focus on western forests.

Altered Precipitation

The amount, distribution and timing of precipitation events is changing. In general, precipitation events are occurring less frequently, but are more likely to be intense.

Altered Water Levels

Increasing temperatures have been observed to lead to reduced lake levels due to increased evaporation. Altered water levels can negatively impact people and the environment.

Changes in Mountain Snowpack

In a warming climate, more precipitation will be expected to fall as rain rather than snow in most areas—reducing the extent and depth of snowpack. Changes in mountain snowpack can affect agriculture, winter recreation, and tourism in some areas, as well as plants and wildlife.

Changing Ocean Systems

Key changes to ocean systems include acidification, rising sea levels, and strengthening storms. Impacts to ocean habitats are detailed in the discussion of coral bleaching and reef degradation in the species and habitats section.

Changing Temperatures

Temperatures are rising. Climate change has already increased average temperatures enough to shift seasons — spring comes earlier and fall frosts arrive later. These shifts in seasons compel some species to migrate farther north or to higher elevations. Trends indicating more extreme temperatures have been observed in both air temperatures and water temperatures.

Changing Water Regimes

Impacts of changing water regimes include altered precipitation, altered water levels, and greater flood risk. Together these changes pose management challenges and present conservation opportunities to the land trust community.

Climate Change and Wildlife Health: Direct and Indirect Effects

Climate Change and Wildlife Health: Direct and Indirect Effects highlights how awareness has been growing in recent years about zoonotic diseases — that is, diseases that are transmissible between animals and humans, such as Lyme disease and West Nile virus — due to climate change. The rise of such diseases results from closer relationships among wildlife, domestic animals, and people, allowing more contact with diseased animals, organisms that carry and transmit a disease from one animal to another (vectors), and people.

Climate Change Impacts to Grasslands

Climate change impacts to grasslands and prairies include increased seasonal, annual, minimum, and maximum temperature and changing precipitation patterns. Because these ecosystems are relatively dry with a strong seasonal climate, they are sensitive to climatic changes and vulnerable to shifts in climatic regime.