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.
In 1950, fewer than one-third of the world's people lived in cities. Today more than half do. By 2050, urban areas will be home to some two-thirds of Earth's human population. This scale and pace of urbanization has never been seen in human history.
The report provides a foundation for new scientific collaborations on how cities function, how they grow, and how they can be managed sustainably for decades to come.
Each year the Global Risks Report works with experts and decision makers across the world to identify and analyze the most pressing risks that we face. As the pace of change accelerates, and as risk interconnections deepen, this year’s report highlights the growing strain we are placing on many of the global systems we rely on. The top risks listed in this year's report, which reflect the concerns of global industry leaders, include extreme weather events, natural disasters, and failure of climate change mitigation and adaptation—ranked first, second, and fifth in likelihood and second, third, and fourth in impact, respectively.
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 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.
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.
A private group, the Climate Leadership Council, describes "How a new climate strategy can strengthen our economy, reduce regulation, help working-class Americans, shrink government & promote national security." The group of conservative elder statesmen that authored the statement call it the first time leading Republicans have put forth a concrete, market-based climate solution. Their recommendations are built on four pillars: (1) a gradually increasing carbon tax, (2) carbon dividends for all Americans, (3) border carbon adjustments, and (4) significant regulatory rollback.
Since 2010, United Nations Environment (UNEP) has produced annual Emissions Gap Reports based on requests by countries for an independent scientific assessment of how actions and pledges by countries affect the global greenhouse gas emissions trend, and how this compares to emissions trajectories consistent with the long-term goal of the United Nations Framework Convention on Climate Change. The difference has become known as the emissions gap. In addition to estimating the emissions gap, the reports focus on key options for achieving the emissions reductions necessary to bridge the gap, and provide an assessment of how these can be accelerated and scaled up. Countries have found these emissions gap assessments useful in informing the political process. This seventh Emissions Gap Report is based on requests by countries for an update that focuses on some of the key issues emerging with the adoption of the Paris Agreement and its specific long-term temperature goal.
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.
This report promotes a relatively simple solution to the problem of increasing heat and air pollution in cities: plant more trees. Trees cool the air by casting shade and releasing water vapor, and their leaves can filter out fine particulate matter (PM)—one of the most dangerous forms of air pollution, generated from burning biomass and fossil fuels.
The report documents analysis that tree planting efforts could improve the health of millions of people, and that trees are as cost-effective as many other common solutions. The report also shows that most of the cooling and filtering effects created by trees are fairly localized, so densely populated cities—as well as those with higher overall pollution levels—tend to see the highest overall return on investment (ROI) from tree plantings.
As climate changes and ocean temperatures rise, the abundance, distribution, and life cycles of fish in federally managed ocean fisheries may change too. Federal agencies managing ocean fisheries have limited information to determine exactly how climate change might harm specific fish populations, and may not always understand the potential effects. To better manage climate-related risks, the report recommends (1) the development of guidance on how to incorporate climate information into the fisheries management process, and (2) finalizing Regional Action Plans for implementing the NOAA Fisheries Climate Science Strategy that incorporate performance measures for tracking achievement of the Strategy’s Objectives.
Communities and nations of the 21st century face a great challenge: to protect people from the harm caused by an increasingly volatile climate. The damaging impacts of climate change will grow as the climate changes and adaptation fails to keep pace, unless societies take steps to increase their resilience through aggressive action on both climate mitigation and adaptation.
This report focuses on adaptation, where choosing among possible actions is often not straightforward or intuitive, and highlights 15 principles for decision makers to use to prioritize investments in climate change adaptation.
The U.S. Government Accountability Office examined the approaches of five governments on enhancing resilience through climate change adaptation. This report focuses on fiscal exposure to climate-related risks and describes how selected governments have approached enhancing resilience to weather-related disasters through climate change adaptation and steps the U.S. government has taken to enhance resilience through climate change adaptation.
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.
This peer-reviewed scientific assessment identifies climate change effects on global food security. Climate change is likely to diminish continued progress on global food security through production disruptions that lead to local availability limitations and price increases, interrupted transport conduits, and diminished food safety, among other causes. The assessment is a contribution to the U.S. National Climate Assessment, is called for under the President’s Climate Action Plan, and was led by the U.S. Department of Agriculture.
This report draws upon a large collection of peer-reviewed National Research Council reports and other national and international reports to provide a brief, reader-friendly primer on the complex ways in which the changes currently affecting the Arctic and its diverse people, resources, and environment can—in turn—affect the entire globe. Topics in the booklet include how climate changes currently underway in the Arctic are a driver for global sea level rise, new prospects for natural resource extraction, and rippling effects through the world's weather, climate, food supply, and economy.
Climate change adds uncertainty to already complex global water challenges. Though no standard method has been adopted yet by the World Bank, common practice uses downscaled precipitation and temperature projections from Global Climate Models (GCMs) as input to hydrologic models. While this has been useful in some applications, they often give too wide a dispersion of readings to provide useful guidance for site-specific water resources management and infrastructure planning and design. Rather than design for an uncertain situation selected a priori, the so-called “bottom-up” approaches explore the sensitivity of a chosen project to the effects of uncertainties caused by climate change. Supported by the Water Partnership Program, this book summarizes alternatives explored by a group of organizations that belong to the Alliance for Global Water Adaptation (AGWA), to provide practitioners with the tools to adapt to the realities of climate change by following a decision-making process that incorporates bottom-up thinking.
This Synthesis Report summarizes the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC). This report distills, synthesizes, and integrates the key findings of the three IPCC Working Group contributions—The Physical Science Basis; Impacts, Adaptation, and Vulnerability; and Mitigation of Climate Change—to the AR5 for the benefit of decision makers in government, the private sector, and the general public. The report also includes findings from two Special Reports released in 2011: Renewable Energy Sources and Climate Change Mitigation and Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation. The Synthesis Report confirms that climate change caused by human activities is having impacts on ecosystems and human well-being across the U.S. and around the world.
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.
This publication, known by the acronym SOFIA, is released every two years to provide policymakers and civil society with a global view of fisheries and aquaculture and associated policy issues. The 2014 report includes a special study of initial assessments of vulnerabilities to climate change in fisheries and aquaculture. The full archive is available online.
This report focuses on livestock diseases that are sensitive to climate change. The report aims to help practitioners reduce the risks of key climate-sensitive infectious diseases by strengthening risk management systems for disease outbreaks. The three diseases chosen for the study—Rift Valley fever, Bluetongue, and East Coast fever—spread through “vectors” such as insects and parasites, the prevalence of which fluctuates depending on key weather and climate variables such as temperature and humidity. As the symptoms of climate change continue, the frequency and extent of these diseases are expected to escalate.
Climate change is making the Arctic a greener, warmer, and increasingly accessible place for economic opportunity. However, climate impacts such as sea ice loss and rising ocean acidification are straining coastal community resilience and sound resource stewardship. NOAA's Arctic Action Plan outlines ways for scientists and stakeholders to share their progress regarding this vast, valuable, and vulnerable region.
This Fifth Assessment Report issued by the Intergovernmental Panel on Climate Change (IPCC) Working Group III is a comprehensive assessment by of all relevant options for mitigating climate change through limiting or preventing greenhouse gas emissions, as well as activities that remove them from the atmosphere.
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.
The dramatic impact of climate variability and climate change continued to be felt all over the world throughout 2013. The World Meteorological Organization statement on the status of the global climate in 2013 provides a snapshot of global and regional trends in weather and climate over the past year and highlights some of the year’s most significant extreme events.
This report uses a Question and Answer format to discuss climate change and its causes. The booklet provides an authoritative overview of global climate change for decision makers, policy makers, educators, and other individuals seeking information on climate science.
This report, representing the Intergovernmental Panel on Climate Change (IPCC) Working Group I's contribution to the IPCC Fifth Assessment report (AR5), explores the hard science elements of global climate change.
This report provides a risk-based approach to achieve resilient water security in a changing climate, documents key trends, and highlights best practice from the Organization for Economic Cooperation and Development (OECD) Survey of Policies on Water and Climate Change Adaptation. The report examines options to improve the flexibility of water governance, policy, and financing approaches.
These five Resource Guides facilitate access to existing climate change learning materials and support the development of complementary learning resources. The guides are compiled for selected topics of climate change for which a wealth of learning resources is available and that have been identified as important topics from a country perspective.
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 summary report provides historical and projected estimates of emissions of non-carbon dioxide greenhouse gases (GHGs) from anthropogenic sources. The report provides a consistent and comprehensive estimate of non-CO2 greenhouse gases for 92 individual countries and eight regions. The analysis provides information that can be used to understand national contributions of GHG emissions, historical progress on reductions, and mitigation opportunities. The projections represent a business-as-usual scenario that includes reductions from established sector-specific programs but not economy-wide programs or commitments.
This guide is targeted towards program managers who work in climate change and health adaptation, and provides them with practical information and concrete guidance to mainstream gender throughout all four phases of the project cycle: identification, formulation and design, implementation, and monitoring and evaluation.
This report is the product of collaboration between the World Health Organization and the World Meteorological Organization, and aims to provide sound scientific information on the connections between weather and climate and major health challenges.
Extreme weather and climate events, interacting with exposed and vulnerable human and natural systems, can lead to disasters. This Special Report explores the challenge of understanding and managing the risks of climate extremes to advance climate change adaptation. Some types of extreme weather and climate events have increased in frequency or magnitude, but populations and assets at risk have also increased, with consequences for disaster risk. Opportunities for managing risks of weather- and climate-related disasters exist or can be developed at any scale, local to international.
This special report assesses the scientific literature on the potential role of renewable energy in the mitigation of climate change for policymakers, the private sector, academic researchers, and civil society. It covers six renewable energy sources—bioenergy, direct solar energy, geothermal energy, hydropower, ocean energy and wind energy—as well as their integration into present and future energy systems. It considers the environmental and social consequences associated with the deployment of these technologies, and presents strategies to overcome technical as well as non-technical obstacles to their application and diffusion.
The purpose of this guide—an addendum to regional socioeconomic monitoring guidelines produced by the Global Socioeconomic Monitoring Initiative for Coastal Management (SocMon) and its Pacific counterpart, SEM‐Pasifika—is to provide a minimum set of socioeconomic indicators related to climate change. The aim of these programs is to improve site management of coastal and marine areas by providing simple, user‐friendly guidelines on how to conduct a socioeconomic assessment, which helps coastal managers incorporate community views into adaptive management of marine resources.