Access a range of climate-related reports issued by government agencies and scientific organizations. Browse the reports listed below, or filter by scope, content, or focus in the boxes above. To expand your results, click the Clear Filters link.
As the influences of human-caused global warming continue to intensify, with the Arctic warming significantly faster than the globe overall, the 2021 Arctic Report Card (ARC2021) brings a broad view of the state of the Arctic climate and environment. The ARC2021 provides an update on seven Arctic Vital Signs, from sea ice to snow and air temperatures to tundra greenness, and checks in on three Indicator topics for updates on river discharge, ocean acidification, and observations of substantial Arctic beaver expansion. The noteworthy emerging topics in the four ARC2021 Frostbites—marine debris, marine noise, food access during the COVID-19 pandemic, and glacier and permafrost hazards—share a common link as they look at the impacts of more people and human activity in the Arctic as well as the challenges and hazards people face with the rapidly changing cryosphere. The scientific and observational story of the Arctic is a human story—of climate change, of increased shipping and industrial activity, and of communities responding to local and regional disruptions.
This is the FY22 edition of the U.S. Gllobal Change Research Program's annual report to Congress mandated by the the Global Change Research Act. The report provides an overview of the Program’s progress in delivering on its strategic goals as well as a summary of agency expenditures under USGCRP’s budget crosscut.
The Working Group II contribution to the IPCC Sixth Assessment Report assesses the impacts of climate change, looking at ecosystems, biodiversity, and human communities at global and regional levels. It also reviews vulnerabilities and the capacities and limits of the natural world and human societies to adapt to climate change.
This series of BAMS special reports presents assessments of how human-caused climate change may have affected the strength and likelihood of individual extreme events. The series has been published annually since 2011.
The ninth edition of the report, Explaining Extreme Events in 2019 from a Climate Perspective, presents 15 new peer-reviewed analyses of extreme weather across four continents and one sea during 2019. It features the research of 77 scientists from 7 countries looking at both historical observations and model simulations to determine whether and by how much climate change may have influenced particular extreme events.
Arctic ecosystems and communities are increasingly at risk due to continued warming and declining sea ice. The Arctic marine ecosystem and the communities that depend upon it continue to experience unprecedented changes as a result of warming air temperatures, declining sea ice, and warming waters. This 2019 update to the Arctic Report Card draws particular attention to the Bering Sea region, where declining winter sea ice exemplifies the potential for sudden and extreme change. Indigenous Elders from the Bering Sea region offer their experiences of living at the forefront of climate change.
This Summary for Policymakers summarizes the findings of the AMAP Assessment 2018: Arctic Ocean Acidification report released in October 2018. It offers a review of the latest science relating to regional ocean acidification, the biological responses to it, an overview of case studies and their associated findings, and recommendations for the Arctic Council.
The continuing acidification of the Arctic Ocean is projected to have significant ecological and socioeconomic impacts over coming decades, with consequences both for local communities and globally. This is the overarching finding of the 2018 Arctic Ocean Acidification Assessment, presented at the 2018 Arctic Biodiversity Congress. The assessment, conducted by the Arctic Monitoring and Assessment Programme (AMAP) of the Arctic Council, updates a 2013 assessment and presents the chemical, biological, and socioeconomic impacts of ocean acidification, which is driven primarily by global greenhouse gas emissions.
This special report from the Intergovernmental Panel on Climate change describes the impacts of global warming of 1.5 °C above pre-industrial levels. The report also describes potential global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty.
The Arctic shows no sign of returning to reliably frozen region of recent past decades. Despite relatively cool summer temperatures, observations in 2017 continue to indicate that the Arctic environmental system has reached a "new normal," characterized by long-term losses in the extent and thickness of the sea ice cover, the extent and duration of the winter snow cover and the mass of ice in the Greenland Ice Sheet and Arctic glaciers, and warming sea surface and permafrost temperatures. Issued annually since 2006, the Arctic Report Card is a timely and peer-reviewed source for clear, reliable, and concise environmental information on the current state of different components of the Arctic environmental system relative to historical records. The report is intended for a wide audience, including scientists, teachers, students, decision makers, and the general public interested in the Arctic environment and science.
This BAMS special report presents assessments of how human-caused climate change may have affected the strength and likelihood of individual extreme events. This sixth edition of explaining extreme events of the previous year (2016) from a climate perspective is the first of these reports to find that some extreme events were not possible in a pre-industrial climate.
The sea ice surrounding Antarctica has increased in extent and concentration from the late 1970s, when satellite-based measurements began, until 2015. Although this increasing trend is modest, it is surprising given the overall warming of the global climate and the region. Indeed, climate models, which incorporate our best understanding of the processes affecting the region, generally simulate a decrease in sea ice. Moreover, sea ice in the Arctic has exhibited pronounced declines over the same period, consistent with global climate model simulations. For these reasons, the behavior of Antarctic sea ice has presented a conundrum for global climate change science. The National Academies of Sciences, Engineering, and Medicine held a workshop in January 2016 to bring together scientists with different sets of expertise and perspectives to further explore potential mechanisms driving the evolution of recent Antarctic sea ice variability and to discuss ways to advance understanding of Antarctic sea ice and its relationship to the broader ocean-climate system. This publication summarizes the presentations and discussions from the workshop.
This report documents that the average temperature in 2015 was over one degree higher than pre-industrial times and that the period 2011–2015 was the warmest five-year period on record, consistent with established warming trends. The report further documents that in 2015 another milestone was reached, with globally averaged CO2 levels of 400 parts per million (ppm). The year 2016 is on track to be even warmer and will be the first year in which CO2 at the Mauna Loa Observatory remains above 400 ppm all year, and for many generations to come.
The probability of extreme climate events since 2011, especially those involving extreme high temperatures, has been substantially increased by climate change, often by a factor of 10 or more. The single most significant event in humanitarian terms, with over 250,000 lives lost, was the 2011–2012 famine in the Horn of Africa, where drought was a major factor.
A multi-agency team of researchers developed this Department of Defense report to provide regionalized sea level and extreme water level scenarios for the years 2035, 2065, and 2011 for 1,774 military sites worldwide. The information included in the report is meant to assist decision makers and others in making robust choices to manage their risk of future sea level and extreme water levels.
As climate has warmed over recent years, a new pattern of more frequent and more intense weather events has unfolded across the globe. Climate models simulate such changes in extreme events, and some of the reasons for the changes are well understood. Warming increases the likelihood of extremely hot days and nights, favors increased atmospheric moisture that may result in more frequent heavy rainfall and snowfall, and leads to evaporation that can exacerbate droughts.
Event attribution can answer questions about how much climate change influenced the probability or intensity of a specific type of weather event. As event attribution capabilities improve, they could help inform choices about assessing and managing risk, and in guiding climate adaptation strategies. This report examines the current state of science of extreme weather attribution, and identifies ways to move the science forward to improve attribution capabilities.
A 24-year tradition encompassing the work of 425 authors from 57 countries, 2013's State of the Climate report uses dozens of climate indicators to track patterns, changes, and trends of the global climate system.
The Intergovernmental Panel on Climate Change (IPCC) Working Group II's contribution to the Fifth Assessment Report (AR5) relates to climate impacts, adaptation, and vulnerability. A Summary for Policymakers and the underlying scientific and technical assessment are also available.
This report summarizes the current state of knowledge on potential abrupt changes to the ocean, atmosphere, ecosystems, and high-latitude areas, and identifies key research and monitoring needs. The report calls for action to develop an abrupt change early warning system to help anticipate future abrupt changes and reduce their impacts.
This report evaluates and synthesizes knowledge on climate variability, climate change, and increased ultraviolet radiation and their consequences for the Arctic region.
