Earth system models allow researchers to evaluate the size and strength of various influences on the climate system and identify the human contribution to the warming trend. Earth system models allow researchers to distinguish “internal” climate variability (natural climate cycles) from the effects of “external” influences on the climate, both human and natural (including variations in incoming solar energy, volcanic eruptions, and greenhouse gas emissions from human activities). Model simulations of natural variability from the late 1800s to the present (see figure, orange curves) do not...

Analysis of the costs and benefits of switching to paddy rice production suggests that farmers could increase profits while reducing greenhouse gas emissions. Drainage of organic soils for agriculture has resulted in widespread soil subsidence (sinkage relative to surrounding areas) and increased greenhouse gas emissions. The Sacramento-San Joaquin Delta in California, once an expansive wetland, was drained and converted to agricultural production in the mid-1800s, and has since experienced subsidence rates that are among the highest in the world. Upland crops there are grown on rapidly...

An observing campaign on the West Antarctic Ice Sheet is improving understanding of influences on recent ice loss and the implications for future sea level rise. Antarctica holds the largest reservoir of ice on Earth and is significant contributor to sea level rise. The West Antarctic Ice Sheet, once considered relatively stable, has shed an increasing amount of ice into the surrounding ocean in recent years as the climate in the region has warmed rapidly [ 1 ] [ 2 ]. The ice sheet would cause significant sea level rise if it collapses completely, but scientists do not yet understand when or...

Social science methods and insights can enhance Federal global change research, assessments, and programs. In March 2017, USGCRP’s Social Science Coordinating Committee convened a three-day workshop, “ Social Science Perspectives on Climate Change .” The workshop brought together over 80 participants, including scientists and program managers from 13 Federal agencies, representatives from non-governmental organizations, and academic social scientists from four disciplines: anthropology, archaeology, geography, and sociology. Participants focused on identifying how social science perspectives...

Scientists are combining satellite remote sensing and ground survey data to better understand the impacts of climate change and other disturbances on the health of Pacific Northwest forests and the ecosystem services they provide. Pacific Northwest forests are sensitive to temperature and drought stress and face increased vulnerability to insect pests, diseases, and fires in a changing climate. The frequency and severity of climate-related forest disturbances are expected to continue to increase over the 21st century. These impacts, combined with expected decreases in snowpack and the...

Balloon-borne instruments measure ozone levels high in the tropical atmosphere, providing new data to help refine projections of future climate change as well as educational opportunities for students in participating countries. Ozone is a powerful greenhouse gas and an important contributor to global climate change. Its impact on the climate is strongest in a region of Earth’s upper atmosphere (upper troposphere and lower stratosphere) where it influences the amount of energy that escapes to space. Ozone distribution in this region is influenced by the upward movement of warm air from the...

Regional climate projections can provide information on likely future changes in climate, ecosystems, and water resources at useful scales. In the Pacific Northwest, average temperatures are projected to increase by at least two and up to 15° F by end of the century, dependent on future greenhouse gas emissions levels. Winters are expected to become wetter and summers drier, snowpack will likely decrease substantially, and snowmelt runoff may occur earlier in the year. Wildfires are projected to become more frequent and more severe, and forest types are expected to change. Because the impacts...

Modeling efforts provide new data on the effects of climate change in Antarctica. Between 1998 and 2016, warming in Antarctica has been rapid and significant. Recent observations also reveal increases in snowfall in western Queen Maud Land, East Antarctica that are unprecedented over the past two millennia. To investigate these changes, a team of NSF-sponsored researchers and NASA scientists merged observation-based NSF-funded research with global modeling efforts that benefited from NASA satellite and airborne-based data 1 . Researchers determined that models were underestimating snow...

Researchers are improving understanding of how shifts in climate conditions affect agricultural production, as well as the value of providing advance climate information to producers. Climate variability and change affect agricultural yields and livelihoods 1 . Improving our understanding of how the interaction of climate variability and change affects agricultural production, particularly on regional scales that are more relevant to decision making, is an important research frontier. As part of the joint NSF-USDA National Institute for Food and Agriculture program on Decadal and Regional...

By monitoring trends such as permafrost thaw, shifts in wildfire, and changing wildlife habitats, a multi-year field campaign seeks to provide the scientific basis for informed decision-making in response to change. Climate change in the Arctic and Boreal Region is unfolding faster than anywhere else on Earth. Observations reveal reduced Arctic sea ice, widespread changes to coastlines and waterways, thawing of permafrost soils and decomposition of long-frozen organic matter, and shifts in ecosystem structure and function. These changes have far-reaching impacts in the region as well as...