As climate change increasingly impacts society and ecosystems, demand for reliable information about climate conditions now and in the future is growing. Climate research is conducted by two distinct communities, one working on climate forecasts for the near-term future and the other on climate-change projections over decades to centuries. Despite these different foci, the boundaries between these two communities increasingly overlap, and they share many common methods and challenges. Enhanced collaboration across modeling centers and communities can help create more valuable climate-...
Highlights
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 El Niño/Southern Oscillation (ENSO) phenomenon is a periodic fluctuation of sea-surface temperatures and atmospheric pressure across the tropical Pacific Ocean. During the El Niño phase of the cycle, the eastern tropical Pacific Ocean warms substantially. This can cause significant short-term increases in global-average surface temperatures, and through atmospheric teleconnections, a strong El Niño event can affect weather patterns around the globe. A particularly strong El Niño emerged during the winter/spring season of...

A key challenge for Earth System Models is accurately representing land surface and subsurface processes and their complex interactions in a warming climate. This is true for ecosystems across the globe, but particularly critical for Arctic ecosystems, which are projected to warm at a rate twice that of the global average by the end of the 21st century. The Next-Generation Ecosystem Experiments in the Arctic (NGEE-Arctic) project is addressing this challenge by integrating process studies, ecosystem observations, and computational...

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

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
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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

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.