Summer rains have remained steady over the past 20 years, but are less than historic highs. Temperature has increased, and while the farmland per person is decreasing, population growth has been offset with improved yields.
While summer rains have increased during the past 20 years, temperatures have increased as well, amplifying the effects of droughts. Crop yields are low but the population is growing, pointing to rising food insecurity.
Long-term reduction in rainfall and increasing temperature threaten Chad's future food production prospects; combined with rapid population growth and zones of substantial conflict, increasing numbers of people will be at risk.
Summer rains have remained steady for the past 20 years, but are below the long-term average. Current population and agricultural trends indicate increasing yields have offset population expansion, keeping per capita cereal production steady.
Modest declines in rainfall, accompanied by increases in air temperatures, declining farmland per person, along with trends in population and agriculture could lead to a 30% reduction in per capita cereal production by 2025.
Long-term reduction in rainfall and increasing temperature threaten Uganda's future food production prospects; combined with rapid population growth these factors could increase the number of people who are at risk during the next 20 years.
Analysis of sea-surface temperature in the Indian Ocean shows that warming correlates with east African rainfall; the effect on atmospheric convection and precipitation over the Indian Ocean is greater than that associated with El Niño (ENSO).
Site for a USGS project under the U.S. Global Change Research Program for a national assessment of the impacts of climate variability and change on resources with links to impacts in Alaska, western U.S., public lands, and water resources.
Relations between the geographic distributions of woody plant species and climatic variables in North America. Shows how the spatial distribution of these plants may be expected to change in response to given climatic scenarios.
Small wetlands in this large area have hosted migratory birds for a long time, but with changes in agricultural practice and regional climate those habitats may not remain hospitable to the wild populations.
Combining genetic data with current and predicted climate scenarios, we are modeling the predicted future distributions of wildlife populations in the Arctic and identifying key environmental variables that determine important animal habitat.
Overview of interdisciplinary research studies in Glacier National Park to understand how this mountain wilderness responds to present climatic variability and other external stressors, such as air pollution, and links to detailed reports.
Home page for Coastal and Marine Geology with links to topics of interest (sea level change, erosion, corals, pollution, sonar mapping, and others), Sound Waves monthly newsletter, field centers, regions of interest, and subject search system.
Report with mini-movie and photos on the hypothesis that the atmospheric transport of dust arising from the desertification in northern Africa led to algal infestation of corals, coral diseases, and the near extinction of associated sea urchins.
Explains the important paleoclimatic information we have obtained from this subaqueous cavern. The time-series data show important contrasts with what would be predicted from orbital theory, provoking extensive scientific discussion.
Homepage for Earth Surface Processes Team with research studies in two general categories: climate change and geologic mapping. Links to research activities, available data sets, workshop, and programs.
How climate change affects ground water is more complex than surface water because the residence time of ground water can range from days to tens of thousands of years. Discusses some broad climatic processes may affect groundwater resources.
Information from climate model forecasts, projections of future flows, paleoclimatic indicators, timing of snowmelt, airborne dust, and the effects on vegetation of troublesome pest species indicate the nature and severity of problems looming.
Direct measurement of an important indicator of interannual variability is extended, using geological proxy measures, farther back in time to well before modern measurements were made. This tells us about the history of climate variability.
Accelerating loss of mass, weakening correlation with the Pacific Decadal Oscillation, and increasing mass turnover likely are the result of changes to warmer and drier climate conditions that are affecting three well-studied glaciers.
Review of the Global Change Hydrology Program components relating to hydroclimatology and studies of the biogeochemistry of greenhouse gases with links to research activities, datasets, fact sheets, and other publications and websites.
Proxy methods allow us to estimate ancient ocean temperatures but only if the method is calibrated using modern samples for which we measure the temperature. This is a proxy method using a sediment trap to collect planktonic foraminifera.
The Hydro-Climatic Data Network, or HCDN, consists of streamflow records for 1,659 sites throughout United States and its Territories. Records span the period 1874 through 1988, and represent a total of 73,231 water years of information.
Recent physical changes over time, including trends toward earlier snowmelt runoff, decreasing river ice, and increasing spring water temperatures, may affect salmon populations; we want to know how important these effects are.
Overview of the environmental monitoring component of the international program at the EROS Data Center using Geographic Information Systems (GIS) technology, with links to data, partners, publications, and workshops.
Planned analysis of the sensitivity of groundwater levels to changes in air temperature and precipitation. Changes in groundwater recharge and discharge also will be correlated with other hydrologic indicators.
Research projects intended to create regional and national data that conform to conditions predicted by general circulation models, so that land and wildlife managers can understand the likely consequences of climatic changes in their areas of study.
Sulfate deposition to high-elevation areas has decreased here as a result of reductions in SO2 emissions. Nitrate deposition did not change, whereas ammonium deposition increased, particularly at sites near urban and agricultural areas.
Explains 16 distinct types of scientific information that are needed to understand climate change, including the specific parameters measured, why they are needed, who measures them, and the type and amount of information that are not yet available.
Summary of a circular on USGS environmental research and Chesapeake Bay with links to full document. Includes discussion of the problems of the estuary, restoration efforts, water quality, and effects on ecosystem.
Summary of part of the USGS interdivisional Mississippi Basin Carbon project that will study the changes in climate and the environment through carbon cycle changes recorded in lake sediments in the Upper Mississippi River Basin.
Article from American Scientist on study of the San Francisco Bay estuary as a component of the global climate system showing that natural fluctuations might be mistaken for anthropogenic trends affecting waterflow and salinity.
Broad overview of USGS research and monitoring designed to understand current changes in the context of prehistoric and recent earth processes, distinguishing between natural and human-influenced changes, and recognizing ecological and physical responses
This updated subset of USGS streamgages for which the streamflow primarily reflects prevailing meteorological conditions for specified years, screened to exclude sites where human activity affects the natural flow of the watercourse.
Overview of research in the Hawaiian Islands and Guam to gain insight into the structure of coral reefs, to provide the basis for future monitoring, and to understand the influences of natural processes and human activities on coral reef health.
Over 30 years of substantial warming, the timing of life cycle events in maize here has changed, threatening the crop yield by exposing the plant at sensitive phases in its life cycle to increased heat and drought, and lowering the weight of its grains.
Homepage for project on Bear Lake, Idaho-Utah, to study past climate change and effect on lake catchment basins. Includes link to summary, personnel, geology, methods used including coring and seismic surveying, and publications.