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.

Longitudinal cross-section of 1998–2016 SHADOZ ozonesonde total column ozone (O3)

Balloon-borne instruments measure ozone levels high in the tropical atmosphere, providing new data to help refine projections of future climate change as well as educational opportunities for students in participating countries.

Ozone is a powerful greenhouse gas and an important contributor to global climate change. Its impact on the climate is strongest in a region of Earth’s upper atmosphere (upper troposphere and lower stratosphere) where it influences the amount of energy that escapes to space. Ozone distribution in this region is influenced by the upward...

Regional comparisons of submarine (1958–1976 and 1993–1997), ICESat (2003–2007), and CryoSat-2 (2011–2016) ice thickness data, showing declines in ice thickness over time.

Satellite observations of sea ice thickness provide an opportunity to improve seasonal predictions of Arctic sea ice cover.

Arctic sea ice grows and melts each year with the seasons, reaching its low point in September. Summer sea ice cover has shrunk significantly over the past thirty years, although variation from year to year means that the downward trend is not uniform. Arctic sea ice plays a critical role in regulating weather and climate in and beyond the region. Sea ice decline activates a feedback loop in the climate system: as highly...

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...

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...

Forecasts of ocean surface current velocity in the Pacific Ocean off of Baja California generated in part using in-situ observations from NOAA’s Tropical Atmosphere Ocean (TAO)

Upgrades to an observing network in the equatorial Pacific Ocean support valuable forecasts of global shifts in climate and extreme weather.

The El Niño Southern Oscillation (ENSO) is a natural climate phenomenon driven in part by the variability of ocean surface temperatures, atmospheric pressure, and trade winds in the tropical Pacific Ocean. ENSO events, occurring every two to seven years on average, cause widespread shifts in precipitation patterns and weather and climate

...

The 2017 annual minimum ozone detection of 131 Dobson Units over Antarctica was observed on October 9, 2017, about a week later than usual, indicating that ozone levels may be starting to recover.

Interagency collaboration sustains long-term measurements that track the health of the ozone layer.

Ozone gas in the upper atmosphere protects the planet’s surface from harmful solar radiation. The Antarctic ozone hole was discovered in 1985, increasing concerns about human emissions of gases that destroy ozone and the negative consequences for life on Earth. Two years later, the international community signed the Montreal Protocol, an international treaty designed to protect the ozone layer through regulation of ozone-depleting compounds. Later...

Collaboration across the modeling community supports critical experiments and scientific advancement.

U.S. climate modeling centers play a central role in understanding and predicting global change on seasonal to centennial timescales. They are engaged in the Coupled Model Intercomparison Project (CMIP), which produces climate projections underpinning the assessments conducted by the Intergovernmental Panel on Climate Change and the U.S. National Climate Assessment. Models developed by these centers are designed for different purposes, from providing operational forecast...

A lake near Fairbanks, Alaska shows signs of thawing permafrost below the surface

By monitoring trends such as permafrost thaw, shifts in wildfire, and changing wildlife habitats, a multi-year field campaign seeks to provide the scientific basis for informed decision-making in response to change.

Climate change in the Arctic and Boreal Region is unfolding faster than anywhere else on Earth. Observations reveal reduced Arctic sea ice, widespread changes to coastlines and waterways, thawing of permafrost soils and decomposition of long-frozen organic matter, and shifts in ecosystem structure and function. These changes have far-reaching impacts in the...

USGCRP co-led an international group of funders and implementers in initiating development of a collaborative research action.

The Belmont Forum is an international partnership between national research funding agencies and international science organizations focused on advancing transdisciplinary global change science and accelerating its application. Its Collaborative Research Actions (CRAs) combine natural science, social science, and stakeholder perspectives to produce knowledge for understanding and responding to global environmental change. In November...

GlobalChange.gov

Utility

Global search

Share

Highlights

Measuring ozone in the tropics

Advancing seasonal predictions of Arctic sea ice

Understanding carbon cycling in Arctic ecosystems

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

Exploring human and natural influences on climate

Strengthening critical observations of the tropical ocean and atmosphere

Monitoring recovery of the ozone layer

Enhancing coordination among U.S. modeling centers

Monitoring change in Alaska and the Arctic

Developing international support for research on climate, environment, and human health