To achieve goals for climate and economic growth, "negative emissions technologies" (NETs) that remove and sequester carbon dioxide from the air will need to play a significant role in mitigating climate change. Unlike carbon capture and storage technologies that remove carbon dioxide emissions directly from large point sources such as coal power plants, NETs remove carbon dioxide directly from the atmosphere or enhance natural carbon sinks. Storing the carbon dioxide from NETs has the same impact on the atmosphere and climate as simultaneously preventing an equal amount of carbon dioxide from being emitted. Recent analyses found that deploying NETs may be less expensive and less disruptive than reducing some emissions, such as a substantial portion of agricultural and land-use emissions and some transportation emissions. In 2015, the National Academies published Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration, which described and initially assessed NETs and sequestration technologies. This report acknowledged the relative paucity of research on NETs and recommended development of a research agenda that covers all aspects of NETs from fundamental science to full-scale deployment. To address this need, Negative Emissions Technologies and Reliable Sequestration: A Research Agenda assesses the benefits, risks, and "sustainable scale potential" for NETs and sequestration. This report also defines the essential components of a research and development program, including its estimated costs and potential impact.

The term 'terrestrial carbon' refers to carbon contained in vegetation or soil stocks. The global carbon cycle plays an important role in sustaining agricultural productivity, biodiversity and forest ecosystems processes. This report identifies a framework for the systematic observation and assessment of carbon stocks on land and in the atmosphere, highlights a number of challenges that need to be addressed and outlines an approach to implement an initial observing system.

The term 'terrestrial carbon' refers to carbon contained in vegetation or soil stocks. The global carbon cycle plays an important role in sustaining agricultural productivity, biodiversity and forest ecosystems processes. This report presents the results of a workshop, held in Canada in February 2000 and organised by the Global Terrestrial Observing System (GTOS) in collaboration with the International Geosphere-Biosphere Programme (IGBP). The workshop was designed to review existing data and observation requirements regarding terrestrial carbon, identify major gaps and propose solutions.

This report summarises the discussions and recommendations of a workshop held in 2001, within the framework of the Terrestrial Carbon Observation (TCO) initiative. This workshop focused on the development of a systematic and collaborative approach to improving "in situ" or ground-based carbon data availability. The benefits of improved "in situ" terrestrial carbon observation will mean that countries can make more informed decisions related to the sustainable use and management of land resources.

Trees, CO2 concentration, climate change, herbivores, temperature.

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 183. For carbon sequestration the issues of monitoring, risk assessment, and verification of carbon content and storage efficacy are perhaps the most uncertain. Yet these issues are also the most critical challenges facing the broader context of carbon sequestration as a means for addressing climate change. In response to these challenges, Carbon Sequestration and Its Role in the Global Carbon Cycle presents current perspectives and research that combine five major areas: The global carbon cycle and verification and assessment of global carbon sources and sinks Potential capacity and temporal/spatial scales of terrestrial, oceanic, and geologic carbon storage Assessing risks and benefits associated with terrestrial, oceanic, and geologic carbon storage Predicting, monitoring, and verifying effectiveness of different forms of carbon storage Suggested new CO2 sequestration research and management paradigms for the future. The volume is based on a Chapman Conference and will appeal to the rapidly growing group of scientists and engineers examining methods for deliberate carbon sequestration through storage in plants, soils, the oceans, and geological repositories.

NASA's Earth Science Division (ESD) conducts a wide range of satellite and suborbital missions to observe Earth's land surface and interior, biosphere, atmosphere, cryosphere, and oceans as part of a program to improve understanding of Earth as an integrated system. Earth observations provide the foundation for critical scientific advances and environmental data products derived from these observations are used in resource management and for an extraordinary range of societal applications including weather forecasts, climate projections, sea level change, water management, disease early warning, agricultural production, and the response to natural disasters. As the complexity of societal infrastructure and its vulnerability to environmental disruption increases, the demands for deeper scientific insights and more actionable information continue to rise. To serve these demands, NASA's ESD is challenged with optimizing the partitioning of its finite resources among measurements intended for exploring new science frontiers, carefully characterizing long-term changes in the Earth system, and supporting ongoing societal applications. This challenge is most acute in the decisions the Division makes between supporting measurement continuity of data streams that are critical components of Earth science research programs and the development of new measurement capabilities. This report seeks to establish a more quantitative understanding of the need for measurement continuity and the consequences of measurement gaps. Continuity of NASA's Earth's Observations presents a framework to assist NASA's ESD in their determinations of when a measurement or dataset should be collected for durations longer than the typical lifetimes of single satellite missions.