Climate Projections Based on Emissions Scenarios for Long-Lived Radiatvely Active Trace Gases and Future Climate Impacts of Short-Lived Radiatively Active Gases and Aerosols
The Earth's climate system derives its energy from the Sun and any variations in the balance between energy received and emitted by the Earth can change the climate. Variations can be caused by natural factors such as changes in solar output and volcanic eruptions, or by anthropogenic changes in atmospheric concentrations of long-lived greenhouse gases, aerosols and other radiatively active short-lived species.
Computer models of the coupled atmosphere-land surface-ocean-sea ice system are essential tools for understanding past climate and making projections of future climate resulting from radiative forcing changes, both natural and anthropogenic. Projections of future climate require estimates (e.g. scenarios of future emissions of long-lived greenhouse gases, aerosols and other short-lived gases. A number of standard scenarios have been developed for the Intergovernmental Panel on Climate Change (IPCC) assessment process, and the future impacts of these have been explored. As part of the Climate Change Science Program (CCSP) process updated scenarios of long-lived greenhouse gases and their atmospheric concentrations are being, developed by the Synthesis and Assessment Product 2.1 team.
Synthesis and Assessment Product (SAP) 3.2, in conformance with the intent of the Strategic Plan for the U.S. Climate Change Science Program, will have two components:
Climate projections for research and assessment based on the range of stabilization scenarios of long-lived greenhouse gas emissions and atmospheric concentrations developed by SAP 2.1a. These stabilization scenarios and their resulting long-lived greenhouse gas concentrations were generated by three unified assessment models.
An assessment of the sign magnitude. and durations of future climate impacts due to changing levels of short-lived gaseous and particulate species which may be subject to future mitigation actions to address air quality issues.
The first component was identified in the CCSP Vision document and has also been an important focus of the latest IPCC study. The second component was also identified in the CCSP Vision document, has been identified by the IPCC as a critical area for continuing study, is an active area of research that is being reported in the reviewed literature, represents a time frame over which available technological solutions can be realistically employed, and focuses on those gas and aerosol species whose future atmospheric levels are also subject to mitigation to control air pollution.
This product is part of a larger suite of CCSP analyses: SAP 2.1 a, Scenarios of Greenhouse Gas Emissions and Atmospheric Concentrations; SAP 2.3 Aerosol Properties and Their Impacts on Climate SAP 3.1 Climate Models: An Assessment of Strengths and Limitations for Uses Applications; SAP 4.3. Analyses of the Effects of Climate Change on Agriculture, Biodiversity, Land, and Water Resources; SAP 4.5. Effects of Climate Change on Energy Production and Use in the United States; and SAP 4.6, Analyses of the Effects of Global Change on Human Health and Welfare and Human Systems.