NOAA CSL: Assessments

WMO/UNEP Scientific Assessments of Ozone Depletion

The Montreal Protocol on Substances that Deplete the Ozone Layer was a landmark global agreement, signed in 1987, to protect the stratospheric ozone layer by phasing out the production and consumption of ozone depleting substances. The Scientific Assessment Panel (SAP) of the Montreal Protocol is charged with providing the scientific information that forms the basis for decisions made by the Parties to the treaty and producing the quadrennial Scientific Assessment of Ozone Depletion. CSL Director David Fahey serves as one of the four co-chairs of the SAP that produces the report. The 2022 Ozone Assessment is the tenth such report, and contains the most up-to-date understanding of stratospheric ozone depletion.

WMO/UNEP Scientific Assessments of Ozone Depletion

35th Anniversary Protecting the Ozone Layer (2022)

Additional UNEP Synthesis reports related to the Montreal Protocol:

Intergovernmental Panel on Climate Change (IPCC) Assessment Reports

Since its inception in 1988, the Intergovernmental Panel on Climate Change (IPCC) Working Group I (WGI) has provided assessments and special reports that inform policy makers worldwide about global climate change. CSL scientists have served as chairs, authors, or reviewers for all of the six Assessment Reports (AR). The latest report, AR6 released in 2021, provides a comprehensive assessment of the physical science basis of climate change since the prior report was released.

IPCC AR6 Climate Change 2021: The Physical Science Basis
IPCC AR5 Climate Change 2013: The Physical Science Basis

U.S. Global Change Research Program National Climate Assessments

USGCRP National Climate Assessment covers

The U.S. Global Change Research Program (USGCRP) is a federally-mandated program that coordinates research and collaboration between 13 U.S. Federal agencies in understanding the natural and man-made forces that influence global climate and the impacts on society. The Global Change Research Act of 1990 mandates that the USGCRP deliver a national climate assessment report to Congress and the President no less than every 4 years. This report provides a synthesis of the cumulative knowledge on climate to inform U.S. policy makers in their efforts to formulate effective strategies for preventing, mitigating, and adapting to the effects of global change. The Fifth National Climate Assessment (NCA5) is the most recent report, published in 2023. CSL Director David Fahey served as a Coordinating Lead Author for the NC4.

NCA5 (2023)

NCA4, Volume I: Climate Science Special Report (2017)
NCA4, Volume II: Impacts, Risks, and Adaptation in the United States (2018)

Tropospheric Ozone Assessment Report (TOAR)

Tropospheric Ozone Assessment Report (TOAR) Global metrics for climate change, human health, and crop/ecosystem research is an official Activity of the International Global Atmospheric Chemistry Project (IGAC), co-chaired by CSL/CIRES scientist Owen Cooper. TOAR's mission is to provide the research community with an up-to-date scientific assessment of the global distribution and trends of tropospheric ozone from the surface to the tropopause. The first phase of TOAR (TOAR-I) spanned 2014–2019 and the findings were published as a series of open-access, peer-reviewed manuscripts in a Special Feature of the journal Elementa. The second phase of TOAR (known as TOAR-II) was initiated by the IGAC SSC on 6 November 2019 and spans the next five years (2020-2024).

TOAR has also built the world's largest database of ozone metrics, calculated consistently for over 9000 surface ozone time series worldwide. Created by Forschungszentrum Jülich, the database is entirely open-access, allowing anyone to download the ozone metrics and conduct their own research.

TOAR-I Elementa: Science of the Anthropocene Special Feature Collection
TOAR Data Portal: Tropospheric Ozone Database

Data and metrics from TOAR were included in The Global Burden of Disease 2019 study to assess the human mortality due to long-term ozone exposure.

Annual State of the Climate Reports

CSL scientists regularly contribute to the annual State of the Climate reports, which are led by NOAA's Center for Weather and Climate at the National Centers for Environmental Information (NCEI) and published by the Bulletin of the American Meteorological Society (BAMS). The State of the Climate report offers annual insights on global climate indicators, extreme weather events, and other important environmental data.

In recent years, CSL scientists have co-authored chapters on Tropospheric Ozone (Owen Cooper, 2015–2024), Stratospheric Water Vapor (Sean Davis and Karen Rosenlof, 2015–2024), and Sudden Stratospheric Warming (Amy Butler, 2019, 2021, and 2024).

Annual State of the Climate Reports

NASA Kinetic and Photochemistry Data Evaluation

Chemical Kinetics and Photochemical Data for Use in Atmospheric Studies is a compilation and evaluation of kinetic and photochemical data for use by modelers in computer simulations of atmospheric chemistry, which is updated and published every 4-5 years. The most recent, Evaluation Number 19, was published in 2020. Evaluations are prepared by the NASA/JPL Panel for Data Evaluation, which is currently chaired by CSL scientist Jim Burkholder.

NASA Kinetic and Photochemistry Data Evaluation

APARC Assessment Reports

APARC (Atmospheric Processes and their Role in Climate; formerly SPARC) is a core project of the World Climate Research Programme (WCRP) that coordinates efforts and assessments relating to climate variability and prediction. Several CSL scientists are involved in APARC activities and have contributed to recent reports.

Additional Assessments & Reports

The annual NOAA Science Report highlights NOAA's research and development achievements across all line organizations over the past year. It is a testament to the innovation of our workforce and partnerships, often requiring years of commitment.

CSL scientists also contribute to numerous other international and national assessments as well as state and regional assessments.

International and national assessments

U.S. state and regional assessments

California - Worked with stakeholders in the California Air Resources Board (CARB) and EPA Region 9 to design and carry out the 2010 CalNex field campaign; communicated findings in a science synthesis report , workshops, scientific meetings, and several publications in the peer-reviewed literature.
Deepwater Horizon Oil Spill - Provided a rapid-turnaround report on air chemistry during the 2010 Deepwater Horizon Oil Spill; the report gave unique and urgently needed information about air quality in the vicinity and downwind of the DWH spill site.
Texas - Continued to provide information and analyses to stakeholders in the Texas Commission on Environmental Quality (TCEQ) regarding findings from the 2000 and 2006 Texas Air Quality Studies (TexAQS 2000 and TexAQS 2006).
Utah - Worked with the Utah Department of Environmental Quality (DEQ) and EPA Region 8 to design and carry out three field campaigns (UBWOS 2012, 2013, 2014) to study the air quality implications of oil and gas exploration activities in Uintah County, focusing especially on determining the processes involved in episodes of high surface ozone in wintertime.
Nevada - Worked with the Nevada Clark County Department of Air Quality (DAQ) to carry out field studies in 2013 to investigate the role of stratospheric intrusions during episodes of high surface ozone near Las Vegas, producing a 2013 report for those stakeholders, and returning to better understand the causes of high-ozone events in 2017 based on those findings.
Colorado - Provided scientific information to the Regional Air Quality Council (RAQC), the lead air quality planning agency for the Denver Metropolitan area; EPA Region 8; the Colorado Department of Public Health and Environment; and local municipalities regarding CSL measurements near oil and gas fields north of Denver.