Changes over Time
Understanding how and why our environment is changing over time is an important element to ensuring our ability to mitigate and adapt to those changes. Understanding the potential impact of change helps us decide how to manage our resources in a way that ensures our natural environment can continue to provide the goods and services on which we as a society depend. To this end, EnviroAtlas provides past and future projections for a subset of variables to investigate historical change and project future change.
What We Provide
Conterminous U.S. | Alaska, Hawaii, Puerto Rico, U.S. Virgin Islands, American Samoa, Gaum, and Northern Mariana Islands
Conterminous U.S.: Climate Projections out to 2099 & Historical Climate Data 1950 - 2005
The NASA Earth Exchange (NEX) scientific collaboration platform has made available downscaled CMIP5 climate projections for the conterminous United States with a spatial grid resolution of 800 meters. The EnviroAtlas team has converted these large complex files into a geospatial format and has made them available through a tool in the EnviroAtlas Interactive Map.
Variables
- Minimum temperature
- Maximum temperature
- Precipitation
- Potential Evapotranspiration
Seasons
- Fall
- Winter
- Spring
- Summer
- All seasons - annual
Representation Concentration Pathways
The Intergovernmental Panel on Climate Change (IPCC) has periodically created climate change scenarios to explore future developments in the global environment with special reference to the production of GHGs and aerosol emissions. These scenarios can be used to make projections about future climate and to understand potential vulnerabilities to climate change. The Representative Concentration Pathways (RCP) used in this work were released in 2014.
RCP 2.6 – This scenario is characterized as having very low greenhouse gas concentration levels. It is a “peak-and-decline” scenario and assumes that GHGs are reduced substantially over time. This is the most benign climate scenario of the four.
RCP 4.5 – This scenario assumes a stabilization will occur shortly after 2100, and assumes less emissions than RCP 6.0, which is also a stabilization scenario.
RCP 6.0 – This is a stabilization scenario in which the increase in GHG emissions stabilizes shortly after 2100 through the application of a range of technologies and strategies for reducing GHG emissions.
RCP 8.5 – This scenario is characterized by increasing GHG emissions over time, and factors in the highest GHG concentration levels of all the scenarios by 2100.
Historical climate – The ensemble average for each RCP model historical run were included. This data is provided for the years 1950-2005.
Alaska, Hawaii, Puerto Rico, U.S. Virgin Islands, American Samoa, Gaum, and Northern Mariana Islands: Changes from recent history to end-of-century
The projections for outside the conterminous U.S. are based on NASA Earth Exchange-Global Daily Downscaled Projections (NEX-GDDP), developed using Global Climate Models (GCMs) runs conducted under the Coupled Model Intercomparison Project Phase 6 (CMIP6).
Variables
- Change in Minimum temperature (°F)
- Change in Maximum temperature (°F)
- Change in Precipitation (in)
- Change in Potential Evapotranspiration (in)
The ensemble mininum change is displayed in the map, but the ensemble medians and maximums of changes can be viewed in a popup by clicking on a feature in the map. Total precipitation and total potential evapotranspiration are also available as fractions in the web service or by downloading the data.
Seasons
- Fall
- Winter
- Spring
- Summer
- All seasons - annual
Shared Socioeconomic Pathways
Scenarios in CMIP6 are called Shared Socioeconomic Pathways (SSPs); SSPs reflect global trends in human activities and changes in GHG and aerosol concentrations. Four SSPs are available in this project.
SSP1-2.6 – This scenario (“Sustainability”) assumes widespread global climate change mitigation policies, clean energy technologies, and natural environment conservancy. This scenario assumes very low GHG concentration levels and reflects the international climate policy goal of limiting global warming below 3.6°F (2.0°C) at 2100 compared to PIA.
SSP2-4.5 – This scenario (“Middle of the Road”) assumes moderate global climate mitigation and adaptation and a slow progress in climate protection measures. This scenario is a medium GHG concentrations pathway. Global temperatures increase by 4.9±1.3°F (2.7±0.7°C) at 2100 compared to PIA.
SSP3-7.0 – This scenario (“Regional Rivalry”) assumes high challenges to mitigation and adaptation. Here, nationalism drives policy, and regional and local take precedence over global issues. Global temperatures increase by 6.5±1.6°F (3.6±0.9°C) at 2100 compared to PIA.
SSP5-8.5 – This scenario (“Fossil-fueled Development”) reflects high challenges to mitigation and low challenges to adaptation. It is characterized by steadily increasing GHG concentrations. It represents the upper boundary of the range of scenarios. Global temperatures increase by 7.9±2.2°F (4.4±1.2°C) at 2100 compared to PIA.
Time periods
The NEX-GDDP-CMIP6 data was processed to calculate projected changes in six climatic variables for each season (fall, spring, summer, winter) and annually for five 30-year periods:
- recent history (1976-2005) to near-term future (2025-2054)
- recent history (1976-2005) to mid-century (2045-2074)
- recent history (1976-2005) to end-of-century (2070-2099)
- near-term future (2025-2054) to mid-century (2045 to 2074)
- near-term future (2025-2054) to end-of-century (2070 to 2099)