Scientists are using aerial and ground survey methods to measure change in Alaska’s interior forests and its impact on ecosystem services. The boreal forests of interior Alaska are changing rapidly as the climate warms. Wildfires are more frequent and more severe, and declines in growth of spruce trees may be driving a shift towards ecosystems normally found in warmer climates. These changes can have significant impacts on the quality of wildlife habitat and ecosystem services that support the subsistence economies of many native Alaskan communities. Despite their importance, the condition of...

Interagency collaboration sustains long-term measurements that track the health of the ozone layer. Ozone gas in the upper atmosphere protects the planet’s surface from harmful solar radiation. The Antarctic ozone hole was discovered in 1985, increasing concerns about human emissions of gases that destroy ozone and the negative consequences for life on Earth. Two years later, the international community signed the Montreal Protocol, an international treaty designed to protect the ozone layer through regulation of ozone-depleting compounds. Later amendments completely phased out production of...

Interagency collaboration supports predictions of Arctic sea cover used by the U.S. Navy and other operational and research organizations. Summer sea ice cover in the Arctic Ocean shrunk significantly since the early 1980s, with particularly rapid declines in recent years 1 . Arctic sea ice plays a key role in regulating weather and climate in and beyond the region 2 , and projections of how sea ice cover will change in the coming years are critical for predicting climate change in the region and its influence on global climate. Several modeling centers that study such changes use the CICE sea...

Field research provides new data advancing our ability to project how tropical forests will respond to a changing climate. Tropical forests store vast amounts of carbon and play a key role in regulating Earth’s climate. As climate changes, these ecosystems have the potential to become a net contributor to global warming if they shift to releasing more carbon to the atmosphere than they absorb 1 . However, how these forests will be affected by a warming climate and changing atmosphere is still uncertain, and is critical for improving model projections of future climate change 2 . In the first...

USGCRP efforts support building global change research capacity in developing countries. USGCRP provides support to help sustain the core operations of three international science organizations: the World Climate Research Program (WCRP) , which is the primary coordination mechanism for international research on the climate system; System for Analysis, Research and Training (START) , which provides opportunities for research, education, and training to scientists, policymakers, and practitioners in developing countries; and Future Earth , which builds interdisciplinary, cross-sectoral...

Interagency efforts develop and deliver science-based information and technologies to help agricultural producers and natural resource managers make optimal management decisions. Farmers, ranchers, and land managers across the country rely on weather and climate information in their management decisions. To help producers and managers better understand the risks and opportunities that extreme weather events and climate change present for their operations, interagency efforts produce and deliver a range of information tools and resources that help guide climate risk management in agriculture...

An assessment of observed and projected climate trends in the United States forms the foundation for comprehensive analyses of climate-related vulnerabilities and risks. USGCRP oversaw the production of the Climate Science Special Report (CSSR) as Volume I of the Fourth National Climate Assessment. CSSR assesses the state of knowledge on human-caused climate change, with a primary focus on the United States, including observed and future projected changes in temperatures, precipitation patterns, extreme weather events, sea-level rise, and ocean acidification. CSSR was released in November 2017...

Interagency collaboration supported rapid response efforts. Periods of heavy rainfall caused extensive flooding across much of the Midwestern United States and Mississippi River Basin in spring 2017, including widespread accumulation of 7–10 inches of rain, flash floods, and long-term river flooding. In response, NASA’s Earth Science Disasters Program assembled a team of scientists at NASA’s Marshall Space Flight Center in Huntsville, Alabama, other NASA centers, and NASA-affiliated partners to assist the U.S. Federal Emergency Management Agency (FEMA) and the U.S. National Guard in their...

Interagency science investigated environmental influences on Zika transmission and helped support response efforts. In February 2016, the World Health Organization declared the Zika outbreak spreading across the Americas since 2015 a Public Health Emergency of International Concern, based on Zika’s previously-unknown association with birth defects. The virus was first discovered in 1947 in Africa and had not previously been found in the Western Hemisphere. By February 2016, the outbreak had spread to 48 countries and territories in the Americas, with virus transmission mainly by the Aedes...

Climate scenarios provide a consistent set of possible future conditions to inform analyses of the risks posed by climate change. The Fourth National Climate Assessment (NCA4) assesses risks to the United States posed by climate and global change. Scenarios that represent a range of plausible future changes in key risk drivers, such as greenhouse gas emissions levels, weather and climate extremes, sea level, population, and land use, are used to guide NCA4’s evaluation of specific climate-related risks in regions and sectors across the United States. Consistent with previous NCAs, NCA4 relies...