Extreme Weather and Climate Events

Forests in California’s Sierra Nevada have become increasingly vulnerable to wildfires due to fire suppression practices, elevated tree mortality and warming temperatures. With these fires growing in severity, these forests are struggling to recover on their own, creating landscapes that are more susceptible to future fires and increased forest loss. Researchers supported by this...

California black oak (Quercus kelloggii) groves are a fundamental part of the landscape in Yosemite Valley and the tree is a cultural keystone species for associated Tribal Nations. For centuries, tribal members have planted, tended, burned, and gathered around black oak. Before Euro-American settlers, the tribes actively maintained a sacred, reciprocal relationship with these groves...

The greater Mississippi River Basin drains 3.2 million square kilometers of land and spans 31 U.S. states. Ninety percent of all U.S. agricultural exports are grown in the Mississippi River Basin, and about 40 percent of the nation's total exports are transported through its major rivers. About 1.3 million people, accounting for $405 billion in annual revenues, work in river-related jobs...

The Squaxin Island Tribe (SIT) is descended from maritime people who have lived and prospered along the shores of the southernmost inlets of the Salish Sea for millennia. Climate change is projected to result in lower low water flows, higher peak water temperatures, and bigger and more frequent floods, due to both changes in peak flows and sea level rise. These changes could have...

Madagascar, a country rich in natural capital and biodiversity but with high levels of poverty, food insecurity, and population growth, faces a number of development challenges, including obtaining sustained financial support from external sources and building internal capacity to address the poor environmental, health, and socio-economic conditions. Climate change poses an increasing...

The Southwest is projected to face significant climate challenges in coming decades; and many of these stresses have already begun. In recent years, multiple climate assessments have been developed for the Southwest that corroborate forecasts of remarkable change to vegetation pattern and the vulnerability of regional ecosystems and suggest that measurable change is already ongoing...

In the Peninsular and Transverse Mountain Ranges of Southern California, montane forests (above 1200 m/4000 ft in elevation) are primarily restricted to “sky islands” of mixed conifer and hardwood species. Montane forests protect the upper watersheds of all the region’s major rivers, providing about 40% of the water used for human, agricultural, and industrial purposes in Southern...

Floods and droughts are forecasted to occur with greater frequency and to be more extreme because of climate change. These changes will increase stresses on both cities and natural systems. Increased flooding can harm infrastructure designed to support human needs and natural systems that support fish and wildlife. Increased drought can have direct impacts on fish and wildlife by...

In the last decade, the annual area burned by wildfires in Alaska has doubled relative to any of the previous four decades, and the current frequency of fire is unprecedented over the past 1,200 years. Wildland fires are one of the main contributors to long-term changes in the structure and function of boreal and subarctic ecosystems. Although fire is a necessary component of regulating...

In recent decades, average temperatures across the U.S. Southwest have increased substantially and precipitation patterns have increased in variability. The warmer temperatures directly impact water availability within Southwest ecosystems, including earlier snowmelts; reduced snowpacks, soil moisture, and streamflow; and lower humidity. Collectively, this has led to an increase in...

Over two-thirds of all landbirds (i.e. birds that spend the majority of their lives in terrestrial environments) in North America migrate long-distances to areas in Mexico, Central and South America and the Caribbean islands. Habitats within Texas and Louisiana support high numbers of birds when they interrupt their migratory journeys through the Gulf of America region to “stopover” for...

Several times during the severe drought of 2010-2015, communities within the jurisdictional territories of the Chickasaw Nation and the Choctaw Nation of Oklahoma were precariously close to running out of water. According to previous studies, temperatures are expected to continue to rise throughout the southern states, and droughts are predicted to be longer and more severe. Even small...