The report describes the activities and plans of the Climate Change Science Program (CCSP), which incorporates the U.S. Global Change Research Program established under the Global Change Research Act of 1990, and the Climate Change Research Initiative that was established by the President in 2001. CCSP coordinates and integrates scientific research on climate and global change supported by 13 participating departments and agencies of the U.S. Government. The document highlights recent advances and progress supported by CCSP-participating agencies in each of the program's research and observational elements, as called for in the Strategic Plan for the U.S. Climate Change Science Program released in July 2003, and later modified in the 2008 CCSP Revised Research Plan. The document also describes how observational and predictive capabilities are being improved and used to create tools to support decisionmaking at local, regional, and national scales to cope with environmental variability and change.

Contrary to popular perception, ECA faces significant threats from climate change, with a number of the most serious risks already in evidence. Vulnerability over the next ten to twenty years will be dominated by socio‐economic factors and legacy issues. Even countries and sectors that stand to benefit from climate change are poorly positioned to do so. The next decade offers a window of opportunity for ECA countries to make their development more resilient to climate change while reaping numerous co‐benefits.

This booklet highlights key findings of Global Climate Change Impacts in the United States, a state of knowledge report about the observed and projected consequences of climate change for our nation and people. It is an authoritative scientific report written in plain language, with the goal of better informing public and private decision making at all levels. The report draws from a large body of scientific information including the set of 21 synthesis and assessment products from the U.S. Global Change Research Program, the assessments of the Intergovernmental Panel on Climate Change, and much more. It also includes new information published since these assessments were released. While the primary focus of the report is on the impacts of climate change in the United States, it also discusses some of the actions society is already taking or can take to respond to the climate challenge. These include limiting climate change by, for example, reducing emissions of heat-trapping gases or increasing their removal from the atmosphere. The importance of our current choices about heat-trapping emissions is underscored by comparing impacts resulting from higher versus lower emissions scenarios. Choices about emissions made now will have far-reaching consequences for climate change impacts, with lower …

This extended report of the IPCC Expert Meeting on the Science of Alternative Metrics that was held in Oslo 18-20 March 2009 is provided in response to an invitation from the UN Framework Convention on Climate Change Ad Hoc Working Group on Further Commitments for Annex I Parties under Kyoto Protocol (UNFCCC AWG-KP) to the Intergovernmental Panel on Climate Change (IPCC) to undertake further technical assessment of alternative common metrics which are used to calculate the CO2 equivalence of anthropogenic emissions by sources, and removals by sinks, of greenhouse gases listed in Annex A to the Kyoto Protocol. The outcome of the expert meeting was an agreed set of key conclusions and recommendations to UNFCCC in response to the request of the AWG-KP as well as more specific recommendations to the scientific community regarding research needs and ones relevant to the scoping of the IPCC's Fifth Assessment Report (AR5). These were presented to the IPCC Plenary in a short report at its 30th session in Antalya, 21-23 April 2009. The current full report of the expert meeting amplifies those conclusions and recommendations and includes the extended abstracts of the meeting presentations as well as a general bibliography.

Climate change has reached the apex of the global agenda at a time when China faces significant development and energy security challenges. The political leadership and leading intellectuals are debating the direction of a new development pathway that provides both growth to meet development objectives, and dramatically reduces energy intensity and pollution. While the official position has not changed significantly, there are four key aspects that illustrate how climate change is conceived by the Chinese leadership. This signals that China may come to play a much more important role in global mitigation of climate change than was thought only a couple of years ago.

This guide aims to help individuals and communities know and understand Earth’s climate, the impacts of climate change, and approaches to adaptation or mitigation. The guide aims to promote greater climate science literacy by providing an educational framework of principles and concepts. The guide can serve educators who teach climate science as a way to meet content standards in their science curricula.

This report critically reviews current knowledge about global distributions and properties of atmospheric aerosols as they relate to aerosol impacts on climate. It assesses possible steps to substantially reduce uncertainties in aerosol radiative forcing estimates.

This report discusses the current state of understanding about the characteristics and implications of uncertainty related to climate change and variability to an audience of policymakers, decision makers, and members of the media and general public with an interest in developing a fundamental understanding of the issue.

This document is part of the Synthesis and Assessment Products described in the U.S. Climate Change Science Program (CCSP) Strategic Plan. The U.S. Government's CCSP is responsible for providing the best science-based knowledge possible to inform management of the risks and opportunities associated with changes in the climate and related environmental systems. To support its mission, the CCSP has commissioned 21 "synthesis and assessment products" (SAPs) to advance decision making on climate change-related issues by providing current evaluations of climate change science and identifying priorities for research, observation, and decision support. This Synthesis and Assessment Product (SAP), developed as part of the U.S. Climate Change Science Program, examines potential effects of sea-level rise from climate change during the twenty-first century, with a focus on the mid-Atlantic coast of the United States. Using scientific literature and policy-related documents, the SAP describes the physical environments; potential changes to coastal environments, wetlands, and vulnerable species; societal impacts and implications of sea-level rise; decisions that may be sensitive to sea-level rise; opportunities for adaptation; and institutional barriers to adaptation.

This Synthesis and Assessment Product focuses on the connection between the scientific ability to predict climate on seasonal scales and the opportunity to incorporate such understanding into water resource management decisions. It directly addresses decision support experiments and evaluations that have used seasonal-to-interannual forecasts and observational data, and is expected to inform (1) decision makers about the relative success of experiences of others who have experimented with these forecasts and data in resource management; (2) climatologists, hydrologists, and social scientists on how to advance the delivery of decision-support resources that use the most recent forecast products, methodologies, and tools; and (3) science and resource managers as they plan for future investments in research related to forecasts and their role in decision support. It is important to note, however, that while the focus of this Product is on the water resources management sector, the findings within this Synthesis and Assessment Product may be directly transferred to other sectors.

This book is the most comprehensive report to date on the wide range of impacts of climate change in the United States. It is written in plain language to better inform members of the public and policymakers. The report finds that global warming is unequivocal, primarily human-induced, and its impacts are already apparent in transportation, agriculture, health, and water and energy supplies. These impacts are expected to grow with continued climate change - the higher the levels of greenhouse gas emissions, the greater the impacts. The report illustrates how these impacts can be kept to a minimum if greenhouse gas emissions are reduced. The choices we make now will determine the severity of climate change impacts in the future. This book will help citizens, business leaders, and policymakers at all levels to make informed decisions about responding to climate change and its impacts. Likely to set the policy agenda across the US for the next few years Features examples of actions currently being pursued in various regions to address climate change. Summarizes in one place the current and projected affects of climate change in the United States

This Climate Change Science Program Synthesis and Assessment Product addresses current capabilities to integrate observations of the climate system into a consistent description of past and current conditions through the method of reanalysis. In addition, the Product assesses present capabilities to attribute causes for climate variations and trends over North America during the reanalysis period, which extends from the mid-twentieth century to the present. This Product reviews Past Climate Variability and Change in the Arctic and at High Latitudes. Paleoclimate records play a key role in our understanding of Earth's past and present climate system and in our confidence in predicting future climate changes. Paleoclimate data help to elucidate past and present active mechanisms of climate change by placing the short instrumental record into a longer term context and by permitting models to be tested beyond the limited time that instrumental measurements have been available. Recent observations in the Arctic have identified large ongoing changes and important climate feedback mechanisms that multiply the effects of global-scale climate changes. As discussed in this report, paleoclimate data show that land and sea ice have grown with cooling temperatures and have shrunk with warming ones, amplifying temperature changes while causing and responding to …

This Report (SAP 4.2) focuses on the thresholds of Climate Change in Ecosystems. As defined in this Synthesis and Assessment Report, 'an ecological threshold is the point at which there is an abrupt change in an ecosystem quality, property, or phenomenon, or where small changes in one or more external conditions produce large and persistent responses in an ecosystem'.Ecological thresholds occur when external factors, positive feedbacks, or nonlinear instabilities in a system cause changes to propagate in a domino-like fashion that is potentially irreversible. This report reviews threshold changes in North American ecosystems that are potentially induced by climatic change and addresses the significant challenges these threshold crossings impose on resource and land managers. Sudden changes to ecosystems and the goods and services they provide are not well understood, but they are extremely important if natural resource managers are to succeed in developing adaptation strategies in a changing world. The report provides an overview of what is known about ecological thresholds and where they are likely to occur. It also identifies those areas where research is most needed to improve knowledge and understand the uncertainties regarding them. The report suggests a suite of potential actions that land and resource managers …

This document is part of the Synthesis and Assessment Products (SAP) described in the U.S. Climate Change Science Program (CCSP) Strategic Plan. This report is meant to reduce uncertainty in projections of how the Earth's climate and related systems may change in the future. It provides scientific information for supporting the decision-making audience and the expert scientific and stakeholder community.

This Synthesis and Assessment Product (SAP 2.4) focuses on the Climate models. Depletion of the stratospheric ozone layer by human-produced ozone-depleting substances has been recognized as a global environmental issue for more than three decades, and the international effort to address the issue via the United Nations Montreal Protocol marked its 20-year anniversary in 2007. Scientific understanding underpinned the Protocol at its inception and ever since. As scientific knowledge advanced and evolved, the Protocol evolved through amendment and adjustment. Policy-relevant science has documented the rise, and now the beginning decline, of the atmospheric abundances of many ozone-depleting substances in response to actions taken by the nations of the world. Projections are for a return of ozone-depleting chemicals (compounds containing chlorine and bromine) to their "pre-ozone-depletion" (pre-1980) levels by the middle of this century for the midlatitudes; the polar regions are expected to follow suit within 20 years after that. Since the 1980s, global ozone sustained a depletion of about 5 percent in the midlatitudes of both the Northern Hemisphere and Southern Hemisphere, where most of the Earth's population resides; it is now showing signs of turning the corner towards increasing ozone. The large seasonal depletions in the polar regions are …

This document is part of the Synthesis and Assessment Products (SAP) described in the U.S. Climate Change Science Program (CCSP) Strategic Plan. This report is meant to synthesize and communicate the current state of understanding about the characteristics and implications of uncertainty related to climate change and variability to an audience of policymakers, decision makers, and members of the media and general public with an interest in developing a fundamental understanding of the issue.

This report focuses on the Climate Projections Based on Emissions Scenarios. The influence of greenhouse gases and particle pollution on our present and future climate has been widely examined. While both long-lived (e.g., carbon dioxide) and short-lived (e.g., soot) gases and particles affect the climate, other projections of future climate, such as the IPCC reports focus largely on the long-lived gases. This U.S. Climate Change Science Program Synthesis and Assessment Product provides a different emphasis. The authors examine the effect of long-lived greenhouse gases on the global climate based on updated emissions scenarios produced by another CCSP Synthesis and Assessment Product (SAP 2.1a). In these scenarios, atmospheric concentrations of the long-lived greenhouse gases leveled off, or stabilized, at predetermined levels by the end of the twenty-first century (unlike in the IPCC scenarios). However, the projected future temperature changes fall within the same range as those projected for the latest IPCC report. The authors confirm the robust future warming signature and other associated changes in the climate.

Long-term, high-accuracy, stable environmental observations are essential to define the state of the global integrated Earth system, its history and its future variability and change. Observations for climate include: (1) operational weather observations, when appropriate care has been exercised to establish high accuracy; (2) limited-duration observations collected as part of research investigations to elucidate chemical, dynamical, biological, or radiative processes that contribute to maintaining climate patterns or to their variability; (3) high accuracy, high precision observations to document decadal-to-centennial changes; and (4) observations of climate proxies, collected to extend the instrumental climate record to remote regions and back in time to provide information on climate change at millennial and longer time scales. This report was requested by the United Nations Framework Convention on Climate Change (UNFCCC) in order to serve as input to see how progress has been made with respect to the Global Climate Observing System (GCOS) Implementation Plan developed in 2004 In accordance with the UNFCCC guidelines, the sections of the report delineate specific U.S. climate monitoring activities in several distinct yet integrated areas as follows: (1) common issues; (2) non-satellite atmospheric observations; (3) non-satellite oceanic observations; (4) non-satellite terrestrial observations; (5) satellite global atmospheric, oceanic, and terrestrial …

This Synthesis and Assessment Product (SAP), Uses and Limitations of Observations, Data, Forecasts, and Other Projections in Decision Support for Selected Sectors and Regions. This is part of a series of 21 SAPs produced by the CCSP aimed at providing current assessments of climate change science to inform public debate, policy, and operational decisions. This SAP focuses on the use of climate observations, data, forecasts, and other projections in decision support.

This Synthesis and Assessment Product (SAP 3.1) focuses on the Climate models. Scientists extensively use mathematical models of Earth's climate, executed on the most powerful computers available, to examine hypotheses about past and present-day climates. Development of climate models is fully consistent with approaches being taken in many other fields of science dealing with very complex systems. These climate simulations provide a framework within which enhanced understanding of climate-relevant processes, along with improved observations, are merged into coherent projections of future climate change. This report describes the models and their ability to simulate current climate.

The report describes activities and plans of the Climate Change Science Program (CCSP), highlighting recent progress in each of the program's research and observational elements. The document also describes how observational and predictive capabilities are being improved and used to create tools to support decision making at local, regional, and national scales to cope with environmental variability and change.

The U.S. Government's Climate Change Science Program (CCSP) is responsible for providing the best science-based knowledge possible to inform management of the risks and opportunities associated with changes in the climate and related environmental systems. To support its mission, the CCSP has commissioned 21 "synthesis and assessment products" (SAPs) to advance decision making on climate change-related issues by providing current evaluations of climate change science and identifying priorities for research, observation, and decision support. This Report-SAP 4.4-focuses on federally managed lands and waters to provide a "Preliminary Review of Adaptation Options for Climate-Sensitive Ecosystems and Resources." It is one of seven reports that support Goal 4 of the CCSP Strategic Plan to understand the sensitivity and adaptability of different natural and managed ecosystems and human systems to climate and related global changes. The purpose of SAP 4.4 is to provide useful information on the state of knowledge regarding adaptation options for key, representative ecosystems and resources that may be sensitive to climate variability and change. As its title suggests, this report is a preliminary review, defined as "the process of collecting and reviewing available information about known or potential adaptation options."

This is a children's book where the characters build a time machine that lets them visit alternate futures based on the decisions they make in the present. The story provides a glimpse of a post-apocalyptic dystopia as a result of severe global climate change, as well as a future utopian ideal that comes as a result of implementing massive changes to land use and food and energy production.

This document is part of the Synthesis and Assessment Products described in the U.S. Climate Change Science Program (CCSP) Strategic Plan. Changes in extreme weather and climate events have significant impacts and are among the most serious challenges to society in coping with a changing climate. This Synthesis and Assessment Product (SAP 3.3) focuses on weather and climate extremes in a changing climate. Many extremes and their associated impacts are now changing. For example, in recent decades most of North America has been experiencing more unusually hot days and nights, fewer unusually cold days and nights, and fewer frost days. Heavy downpours have become more frequent and intense. Droughts are becoming more severe in some regions, though there are no clear trends for North America as a whole. The power and frequency of Atlantic hurricanes have increased substantially in recent decades, though North American mainland land-falling hurricanes do not appear to have increased over the past century. Outside the tropics, storm tracks are shifting northward and the strongest storms are becoming even stronger. It is well established through formal attribution studies that the global warming of the past 50 years is due primarily to human-induced increases in heat-trapping gases. Such …