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.

A close-up of an ice lake section with methane gas bubbles trapped beneath the surface.

Recent studies are improving the ability to quantify ecosystem carbon dynamics and greenhouse gas exchange in changing Arctic and boreal landscapes.

Northern high latitudes are warming at more than twice the global average, driving permafrost thaw, changes in surface water extent, increased wildfire, and other changes that affect how much carbon is stored in and emitted to the atmosphere by soils, vegetation, and inland waters.^{^[1]} Measuring the flow of carbon between ecosystems, landscapes, and the...

Spatial distribution of A, annual carbon loss and gain across upland Alaska 1950–2009 and B, historical fire scars from 2000–2009 among the five Landscape Conservation Cooperative (LCC) regions.

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 21^st 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...

Modeling Permafrost Response to Climate Change

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...

Improving Predictions of Changing Arctic Ecosystems

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...

Tracking Methane Emissions from Arctic Tundra

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 NASA CARVE and DOE NGEE-Arctic projects are combining airborne and ground-based campaigns to understand the importance of natural emissions from the Alaskan tundra. (Source: J. B. Curtis, LBNL [main photo and left inset]; S. Wullschleger, ORNL [right

In addition to emissions from human activities, natural emissions of greenhouse gases such as carbon dioxide and methane can affect the climate system, and vice versa. Quantifying these natural fluxes, especially in Arctic ecosystems, is critical to understanding how they may interact with human-driven changes to affect future climate. Some research has shown increased emissions of greenhouse gases from tundra and boreal forests during warming in the spring, but little is known about what causes this or whether its occurrence is widespread enough to influence

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Highlights

Studying carbon cycle processes in northern aquatic ecosystems

Assessing Alaska’s carbon resources

Modeling Permafrost Response to Climate Change

Improving Predictions of Changing Arctic Ecosystems

Tracking Methane Emissions from Arctic Tundra

Measuring Natural Greenhouse Gas Emissions in Alaska