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.

Map shows the average active layer thickness (ALT) at the end of the growing season for the Barrow, Alaska region that contains the NGEE Arctic study site.

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...

Figure shows how methane production changes with temperature in (a) surface and (b) deep peat samples that were anaerobically (without oxygen) incubated

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...

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...

AmeriFlux FLUXNET2015 data collection sites overlaid on a map of global land cover types.

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...

Coordinated experiments run across major Earth system models help improve model projections and advance climate science understanding.

Projections of the future state of the Earth system can differ significantly across models, with various potential sources of uncertainty. To better understand the sources of difference and where fundamental scientific understanding can be improved, the Earth system modeling community uses a set of experiments run across many models known as the ...

Model runs of CMIP5 models without greenhouse gas forcing (orange lines) demonstrate natural variability in average annual global surface temperatures expected without human influence on the climate.

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...

Researchers found that reducing aerosol pollution can achieve both direct and indirect health benefits.

Atmospheric aerosols are tiny airborne particles that can dramatically affect the Earth’s climate through their influence on the flow of energy between Earth’s surface and space. Some aerosols have a cooling effect by reflecting solar energy back into space, while other aerosols containing substantial amounts of carbon warm their surroundings by absorbing the sun’s energy, and can also directly harm human health when particles are at ground...

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...

Climate scenarios provide a consistent set of possible future conditions to inform analyses of the risks posed by climate change.

The Fourth National Climate Assessment (NCA4) assesses risks to the United States posed by climate and global change. Scenarios that represent a range of plausible future changes in key risk drivers, such as greenhouse gas emissions levels, weather and climate extremes, sea level, population, and land use, are used to guide NCA4’s evaluation of specific climate-related risks in regions and sectors across the...

A Spanish language translation of the executive summary of USGCRP’s report The Impacts of Climate Change on Human Health: a Scientific Assessment is now available.

Climate and health assessment information has been shared widely through a number of platforms and formats, including a Spanish translation of the report overview.

In April 2016, the USGCRP released The Impacts of Climate Change on Human Health in the United States: A Scientific Assessment, a groundbreaking report detailing the major risks and vulnerabilities to human health posed by...

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Highlights

Understanding carbon cycling in Arctic ecosystems

Understanding carbon cycling in warming northern peatlands

Assessing Alaska’s carbon resources

Supporting twenty years of carbon cycle understanding

Collaborative modeling experiments to improve understanding of the future of the Earth system

Exploring human and natural influences on climate

Understanding the health benefits of reducing aerosol pollution

Modeling future climate, vegetation, and hydrology in the Pacific Northwest

Scenario products supporting the Fourth National Climate Assessment

Expanding access to climate change and human health assessment information