

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.
Scientists are gaining new understanding of processes that control greenhouse gas emissions from Arctic permafrost, a potential driver of significant future warming.
Rapid warming in the Arctic is causing carbon-rich soils known as permafrost, previously frozen for millennia, to thaw. As thawing soils decompose, the greenhouse gases carbon dioxide and methane are released into the atmosphere in varying proportions depending on the conditions under which decomposition occurs. Permafrost emissions could contribute significantly to future warming...
Researchers are experimentally warming northern peatlands to understand carbon cycling in the climate of the future.
Northern peatlands hold large stocks of organic carbon in their soils that are vulnerable to release into the atmosphere as the greenhouse gases carbon dioxide and methane as the climate warms. Emissions of methane, which has about 28 times the warming power...
An assessment of carbon stocks in Alaska’s soils and vegetation helped set a baseline for monitoring future change.
Alaska’s soils and vegetation store vast quantities of carbon. Increases in temperature throughout the 21st century may increasingly expose these stores to loss from increased wildfire, permafrost thaw, and other changes that could turn Alaska’s ecosystems into a net source of carbon to the atmosphere. However, much of Alaska has previously not been considered in any major national...
A global data collection network has built a strong foundation for carbon cycle understanding.
The AmeriFlux Network, which is supported by the Department of Energy, connects scientists from across the Western Hemisphere studying the exchange of carbon, water, and energy between ecosystems and the atmosphere. Since its launch in 1996, AmeriFlux has built a data record from 213 sites worldwide, called...
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 uncertain¾and is critical...
A new research network aims to accelerate discoveries in the science of these important natural carbon sources and sinks.
Coastal wetlands provide protection from wind and waves, support habitats and fisheries, and store large amounts of atmospheric carbon dioxide for centuries to millennia. These ecosystems can also be sources of greenhouse gas emissions to the atmosphere; wetlands that do not have the capacity to keep pace with sea-level rise, for example, can erode and release soil carbon rapidly to the atmosphere. Freshwater and brackish wetlands also emit methane, a...
Vast quantities of carbon—twice the size of the current amount in the atmosphere—are stored in frozen permafrost soils in Arctic regions. The Arctic climate is warming much more rapidly than the global average, leaving these carbon pools highly vulnerable to release into the atmosphere as carbon dioxide and methane as soils thaw and decompose, leading to a feedback cycle of further warming and increasing carbon release. The potential for these carbon stocks to increase global-warming rates, and the rapid changes already observed in the permafrost region, have captured the attention 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...