Earth's Radiation Budget

Frequently Asked Questions and Answers

At the direction of Congress, NOAA is developing a research program to investigate natural and human activities which might alter the reflectivity of the stratosphere and the marine boundary layer, and the potential impact of those activities on the Earth system.

The FY20 appropriation provided $4,000,000 for:

  • modeling, assessments, as possible, initial observations and monitoring of stratospheric conditions and the Earth's radiation budget,
  • including the impact of the introduction of material into the stratosphere from
    • changes in natural systems,
    • increased air and space traffic,
    • proposals to inject material to affect climate,
    • and the assessment of solar climate interventions.

The appropriation further directs OAR to improve the understanding of the impact of atmospheric aerosols on radiative forcing, as well as on the formation of clouds, precipitation, and extreme weather.

Funding for Fiscal Year 2020 supported three types of research projects:

  • The first is to develop observational methods to understand baseline aerosol conditions in the stratosphere.
    • Initial observations using instrumented balloons have already started
    • New instruments are being developed for future stratospheric aircraft campaigns
    • Laboratory studies will be initiated to investigate potential stratospheric solar radiation management (SRM) materials
  • Second, models of stratospheric and tropospheric responses to increases in stratospheric aerosol loading are being developed and improved.
  • Third, model investigations are also exploring the potential for aerosol injections to increase the reflectivity, or brighten, low-altitude marine clouds.

These projects are geared both towards producing immediate results and building a foundation for future research.

Science by its nature is collaborative. In pursuing its core mission of Science, Service and Stewardship of the Earth system, NOAA has a long and productive history of collaborating with other US and international scientific institutions.

NOAA is supporting development of computer modeling of stratospheric aerosols in the NCAR Community Earth System Model (CESM), which will be important for understanding the climate system and evaluating any future aerosol-based climate experiments.

NOAA is also supporting work at the University of Washington’s Cooperative Institute for Climate, Ocean and Ecosystem Studies (CICOES) to develop and improve large eddy simulation models. These models simulate the interactions between aerosols and clouds in the marine boundary layer, and will be used to understand the impacts of marine cloud brightening.

NOAA's research is always subject to input and review from experts at other institutions and by the broader scientific community. Research carried out under this program will be presented at scientific conferences and will ultimately be subject to rigorous peer-review before its publication in scientific journals.

NOAA is studying natural and human activities which might alter the reflectivity of the stratosphere and the marine boundary layer, and the potential impact of those activities on the Earth system. NOAA and its partners have a history of atmospheric research relevant to the Earth Radiation Budget request. They are using models, conducting laboratory experiments, and acquiring atmospheric observations to learn more about these important aspects of the Earth system.

By engaging in Earth Radiation Budget research, NOAA does not condone or support the implementation of measures to artificially cool the Earth's surface. Indeed, climate intervention approaches will not address the root of human-caused climate change from increasing greenhouse gas emissions.

NOAA investigates many complex, and sometimes controversial, environmental issues to understand and predict changes in Earth's climate, weather, oceans, and coasts. Any decision to implement climate intervention activities will be made outside of NOAA. NOAA's objective for its research programs are to improve our scientific understanding of the Earth system and thereby provide the needed scientific foundation for societal decision-making on key environmental issues.

The FY20 appropriation enabled NOAA to initiate much-needed "baseline" research to begin to address important knowledge gaps related to the Earth Radiation Budget, including climate intervention proposals. We do not currently understand how critical Earth systems may respond to climate intervention strategies on a global scale.

There are no plans for NOAA to conduct climate intervention experiments in the stratosphere or marine boundary layer.

One goal of NOAA's Earth Radiation Budget program is to identify and quantify the response of the Earth system to climate intervention activities. At present, there are significant knowledge gaps which need to be filled before scientists can provide a comprehensive evaluation of possible climate intervention strategies.

The results of the NOAA program will provide part of the needed scientific foundation required to inform policy decisions related climate intervention proposals which otherwise might be adopted or rejected without sufficient understanding of the consequences or alternatives available.

NOAA research undertaken to assess climate intervention methods will also lead to a better understanding of the role of cloud-aerosol interactions in the Earth system, which is the main uncertainty in projecting future climate.

Observation programs initiated by this research will be able to determine if climate intervention in the stratosphere is already being conducted in the absence of international protocols.