Much of the precipitation along the U.S. West Coast is delivered by phenomena known as “atmospheric rivers”—narrow bands of moist air that may extend for thousands of miles across regions outside of the tropics, and play a critical role in regional water supply and storm activity. Atmospheric-river events play a beneficial role in building up Western water supply and snowpack but are also the source of a large majority of floods in the region. Many uncertainties about key processes that affect storm development...
Since 1989, the U.S. Global Change Research Program (USGCRP) has submitted annual reports to Congress called Our Changing Planet. The reports describe the status of USGCRP research activities, provide progress updates, and document recent accomplishments
In particular, Our Changing Planet highlights progress and accomplishments in interagency activities. These highlights represent the broad spectrum of USGCRP activities that extend from Earth system observations, modeling, and fundamental research through synthesis and assessment, decision support, education, and public engagement. Highlights describe the state of science at the time of publication of each yearly report, and may not reflect more recent advances in understanding. The date of publication of the source report is noted on each highlight page.
The Arctic tundra is a cold, desert-like biome, with a layer of permanently frozen soil and organic matter below the surface containing vast stocks of carbon. As Arctic tundra soils warm in response to climate change, methane emissions from decomposing organic material could increase dramatically, representing a potentially significant positive feedback on climate warming. However, seasonal and climatic influences on methane emissions from these systems are not well understood outside of the summer months, representing a major uncertainty for the Arctic methane budget. To help address a...
The majority of terrestrial (land-based) carbon is stored in soil. With changes in climate and land use, understanding this key player in the carbon cycle is increasingly important. In October 2014, a group of scientists from 13 countries gathered in South Carolina for the Sixth International Workshop on Soil and Sedimentary Organic Matter Stabilization and Destabilization (SOM6). Participants engaged in focused
Tropical cyclones (hurricanes and typhoons) generate serious costs to human life, property, and the economy. Understanding how the behavior of tropical cyclones may change in a warmer climate is important for long-range coastal planning and infrastructure investments to minimize impacts. To help address this prediction challenge, NASA, NOAA, NSF, and DOE have cosponsored a Hurricane Working Group (HWG), organized through the interagency
Extreme events such as heavy rains, severe storms, drought, and heat waves can have devastating effects on infrastructure, the economy, and vulnerable segments of the population. A growing field of climate science seeks to understand the drivers behind extreme events and how they connect to broader climate trends. Building on efforts to monitor the global climate (see Highlight 1), a recent report published in BAMS integrates findings from 20 different research
The international Global Carbon Project released its annual Global Carbon Budget in September 2014, shining a spotlight on rising carbon dioxide emissions and their significance for international efforts to reduce climate change. The 2014 Budget comprises analyses of emissions data for 2013, projections through the end of 2014, and implications for future climate and energy choices. The emissions data are available to...
In addition to being hotbeds of biodiversity, tropical forests are important to Earth’s water, energy, and carbon cycles—but they are increasingly impacted by climate change and human activities. Atmospheric chemistry in the once-pristine Amazon Basin, for example, is rapidly changing with deforestation, biomass burning, and pollution related to development in the region.
Like other forests, tropical forests naturally generate and emit volatile organic compounds that can react with other elements to form aerosols, or fine particles suspended in the
In 2012, spring came earlier for the contiguous United States than in any year since 1900, according to recent research by a team of scientists with the USA National Phenology Network (USA-NPN). This research used the USA-NPN suite of “spring indices”—or algorithms based on the accumulated warmth needed to initiate growth in temperature-sensitive plants, which are validated by nationwide historical
The 2012–2021 Strategic Plan emphasizes the need for synergy between Earth observations and Earth system modeling—two cor- nerstones of global change research. Obs4MIPs (or Observations for Model Intercomparison Projects) is an emerging activity that uses observations to better support the Coupled Model Intercomparison Project (CMIP), an international effort under the
Modeling Earth’s climate furthers priorities of national interest, from experimental research to understand the Earth system to operational forecasts and projections that inform decisions. Coordination among the Nation’s premier modeling centers—particularly between experimental and operational programs (see also Highlight 31)—has the potential to advance forecasting capabilities, yield more robust predictions, and bridge models of near-term weather and longer-term climate that currently are separated by high-uncertainty gaps in coverage.