2020 Year in Review
Climate Research & Development Program
Changes in the environment, land use, and climate can have significant impacts on our Nation’s economy, natural resources, infrastructure, and water, food, and energy security. The Climate Research and Development (Climate R&D) Program funds and provides foundational research to improve understanding of the rates, causes, and consequences of these changes in order to strengthen our Nation’s ability to respond and adapt to change.
The USGS Climate R&D Program strives to advance:
- The understanding of the physical, chemical, and biological components of the Earth
- The causes and consequences of climate and land use change
- The vulnerability and resilience of the Earth to such changes
The Program partners and collaborates with a diverse range of stakeholders in government, academia, and national and international organizations. Our scientists deliver timely and usable science and data to support the Department of the Interior (DOI) bureaus, other Federal agencies, Tribal, State and local governments, and organizations within the private, public, and non-profit sectors.
In 2020, the Climate R&D Program supported:
46 Research Projects
Image: USGS scientists in the field collecting data on Gulkana Glacier, Alaska, Spring 2019.
With over 120 scientists
Image: Scientists take a freshly extracted lake sediment core to shore via boat on Santa Fe Lake, New Mexico.
Located across the U.S. in 20 USGS science centers
Map: USGS Center locations where Climate R&D scientists work.
And produced over 150 peer-reviewed publications
Image: Assortment of publications with Climate R&D authors.
Below we've highlighted just some of the amazing work and research produced by the Program over the course of the last year.
Patterns of Sea Ice Extent in the Bering Sea, Alaska
The Bering Sea is home to some of the most productive ecosystems in the Arctic. The annual growth and retreat of sea ice is crucial for healthy ecosystems that support a billion-dollar fishing industry and Native communities’ subsistence harvesting.
Researchers analyzed the chemistry of a peat core (a sample of partially decayed mosses and organic matter extracted from the ground) collected from St. Matthew Island to gain insight into climate and sea ice extent variability in the Bering Sea region stretching back 5,500 years.
Map: Bering Sea with a pin on St. Matthew Island.
The analysis allowed the researchers to identify periods of time when winds dominated from the North, expanding sea ice, and periods where winds dominated from the South, reducing sea ice. On longer timescales, sea-ice decline was linked to increasing exposure to the sun’s rays in the winter and atmospheric carbon dioxide concentrations.
Image: Pancake ice on the Bering Sea.
Despite variability in the oxygen isotope record over the 5,500-year timescale, the general trend was toward heavier isotopes suggesting a long-term decline in sea-ice extent in the region.
Further, samples of mosses from St. Matthew Island collected in 2018 (a year with anomalously low sea ice extent) were compared with the peat-core record, and the researchers were able to confirm that the sea ice extent in 2018 was the lowest it had been in the last 5,500 years.
Image: Sea ice extent inferred from peat cellulose isotopes (light blue) versus atmospheric carbon dioxide concentrations (purple). Sea ice declines as the level of atmospheric carbon dioxide increases.
Loss of sea ice in the Bering Sea has serious implications for future ecosystem health and could threaten the local fishing industries. Earlier retreat of sea ice is increasing coastal erosion and storm surge impacts to Alaskan communities along the Bering Sea coast and increasing temperatures on land.
Image: Overlooking calm ocean waters and sea ice.
Tracking Warming in the United States' Largest River Basin
Droughts can have severe consequences for agriculture, the economy, river navigation, ecological resources, and local communities’ drinking water. Much of the western U.S. demand for water is approaching or has exceeded supply levels, which makes the threat of drought even greater.
Map: The Missouri River Basin. Shapefile from WBD HU2. National Hydrography Dataset (usgs.gov)
From 2000-2010, the Upper Missouri River Basin (UMRB) in the northern Rocky Mountains underwent a persistent, severe drought, often called “the turn-of-the-century drought.” This drought appeared to surpass the severity of streamflow reductions seen during the Dust Bowl drought of the 1930s.
Climate R&D scientists reconstructed temperature and streamflow for the major water contributing basins of the Missouri River over the last 1,200 years using a regional network of 374 tree-ring records to provide long-term context of changing climate drivers of streamflow. Scientists study tree rings because each year a new ring of growth accumulates on a tree trunk and the thickness of the tree-ring corresponds to the environmental conditions and water availability at the time.
Image: The location of the Missouri River Basin within the continental Untied States (grey watershed, upper right) and the location of the five major mountain headwaters basins (colored watersheds) that define the Upper Missouri River Basin. Reconstructed gages used to develop the estimate of basin-wide mean annual streamflow are shown as triangles.
The network of streamflow and temperature reconstructions, combined with historical climate records, provide a context to evaluate the changing climatic drivers of recent and future droughts, and whether recent events exceed the severity, duration, or magnitude of the pre-Industrial past. By improving understanding of the relationship between warmer temperatures and changes in seasonal precipitation and evapotranspiration, both the results and datasets produced from this work are informing resource managers as they design management strategies to accommodate a range of future climate and land use scenarios.
Image: Clarks Fork of the Yellowstone River in the Upper Missouri River Basin.
Sources of Variability and Uncertainty for Carbon Sequestration in Restored Wetlands
Wetland restoration has been promoted to sequester soil organic carbon and mitigate greenhouse gas emissions that are worsening climate change, but there is still large uncertainty around the rates at which restored wetlands actually sequester carbon.
Image: Wetlands at Cottonwood lake, Stutsmam County, North Dakota.
USGS scientists analyzed a large database of soil organic carbon concentrations from the Prairie Pothole Region, one of the largest wetland ecosystems in North America, to better understand soil properties and carbon sequestration.
They found that soil organic carbon was highly variable within wetlands, with the greatest stocks and sequestration being in the inner portion of the wetland catchment that remains wet the longest.
Map: The Prairie Pothole Region (shaded area) and wetland catchments (black dots) used for this study. Prairie Pothole Region shapefile available in USGS ScienceBase Catalog . Wetland catchments from ( Tangen and Bansal, 2020 ).
They estimated that it takes 20-64 years for the soil organic carbon levels of restored wetlands to reach natural conditions. Since the landscape position of a wetland affects its ability to sequester carbon, this information should be considered to refine future assessments and maximize restored wetlands’ greenhouse gas mitigation potential.
Image: Diagram showing changing soil organic carbon (SOC) stocks and sequestration with wetland catchment position on the landscape.
Influence of Growth Patterns on Tree Mortality Post-Fire in Western Parks
Tree mortality in a forest after a fire is often used to define the severity of the fire, but all of the factors that affect a tree’s mortality after a fire are not fully understood. Patterns of tree growth prior to fire may indicate vigor and ability to recover from injury caused during fire and therefore help to predict which trees injured by fire will actually succumb to their injuries and which will recover.
Climate R&D scientists analyzed data from long-term forest monitoring plots across 10 National Parks in the American West from before and after prescribed burn.
Map: Location of the 10 National Park Service Units used in the study
They found that the likelihood of tree mortality post-fire was not only related to the severity of injury sustained during the fire, but also to average growth rate and long-term (25 years) growth patterns of the tree.
Image: Scientist collecting a tree ring sample, which will provide data on the tree's growth rates and patterns.
Improving our understanding of all the factors that lead to tree death post fire is important so that models of fire severity and forest dynamics can be more accurate in the face of changing climate and fire patterns.
Image: Rim Fire in Yosemite National Park.
Ecological Impacts of Hurricanes in Everglades National Park, Florida
Mangrove forests provide numerous benefits and ecosystem services to coastal areas, like protection from storms and flooding, water filtration, habitat, and carbon sequestration. Tropical cyclones can have a wide variety of ecological effects on mangrove forests and coastal ecosystems. Natural resource managers and ecologists are tasked with anticipating and preparing for these uncertain consequences that may be becoming more frequent and intense with changing climate.
Map: Location of Everglades National Park, Florida, USA.
Strong hurricanes can cause an ecological regime shift by killing mangrove trees and their roots and converting the landscape from mangrove forest to mud flat. With the trees dead, soil elevation loss can occur because of processes like destabilization of soil organic matter, erosion, and compaction of root channels.
To better understand the ecological processes at play after ecological disturbances, Climate R&D scientists studied 20 years of surface elevation change data in mangrove forests and mudflats in an area of Everglades National Park that experienced a regime shift after the intense Labor Day Hurricane of 1935.
Image: A mangrove forest in Everglades National Park.
The results of the work showed that mangrove forest mortality post hurricane can lead to large elevation losses and long-term conversion to mudflats, which has implications for carbon cycling and habitat. This is important because of expected future increases in sea level and tropical cyclone intensity.
Image: A mangrove forest and adjacent mudflat near Big Sable Creek in Everglades National Park (Florida, USA). In this area, mangrove forest mortality and peat collapse due to a powerful tropical cyclone in 1935 led to the conversion of mangrove forests to mudflats. This area was once covered by more extensive mangrove forests but is now a mosaic of mangrove forest and mudflats.
Historically Unprecedented Hurricane Activity in the Gulf of Mexico
Hurricanes are a great threat to the densely populated U.S. Atlantic and Gulf coasts. The relationship between climate and hurricane activity on long timescales is still not very well understood, which makes projecting future trends in hurricane activity with climate change challenging.
To get a better understanding of past hurricane activity in the northern Gulf of Mexico, Climate R&D scientists analyzed sediment cores from coastal lakes in the Florida panhandle. Sediment cores from coastal lakes can tell a story of past intense hurricane landfalls because layers of coarse sediment get deposited by the storms.
Map: Historic (1851-2019) hurricane paths modeling suggests could have caused either minor or major flooding at Basin Bayou and Shotgun Pond. Hurricane track data from NCDC International Best Track Archive for Climate Stewardship (IBTrACS) Project, Version 3 (noaa.gov)
The lake cores revealed patterns of hurricane landfalls for the past 2000 years, extending well past the observational period which covers only 1851 to present. A historically unprecedented period of increased storm activity was identified between 1400 and 800 years ago.
Image: Long sediment core (bottom of figure) with close-ups of four hurricane event deposits within the core (lighter, coarser sediments).
This occurrence of increased storm activity indicates the natural range of hurricane landfalls is greater than the observational record and provides a new baseline context and long-term perspective of hurricane activity in the Gulf of Mexico. This helps improve climate model projections of future hurricane landfalls.
Image: Coring vessel on the shore of Basin Bayou before researchers set out onto the lake to collect the sediment cores.
In Conclusion...
There were many great articles and science products published by the Climate R&D Program during 2020, and we don't have the space to highlight them all here, although we wish we could.
To see all of the work, check out our publications webpage below!
Disclaimer: Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
