Geoengineering Glossary for Policymakers
A living guide to geoengineering terms and acronyms
Academic Working Group (AWG) on International Governance of Climate Engineering—International group of senior academics convened by the FCEA to formulate perspectives on international governance of climate engineering research and potential deployment.
Aerosols—A collection of airborne solid or liquid particles, with a typical size between 0.01 and 10 μm, that reside in the atmosphere for at least several hours. Aerosols may be of either natural or anthropogenic origin. Aerosols may influence climate in several ways: directly through scattering and absorbing radiation, and indirectly by acting a cloud condensation nuclei or modifying the optical properties and lifetime of clouds. (RS)
Afforestation—Planting of new forests on lands that historically have not contained forests. (RS)
Albedo—The fraction of solar radiation reflected by a surface or object, often expressed as a percentage. Snow-covered surfaces have a high albedo, the surface albedo of soils ranges from high to low, and vegetation-covered surfaces and oceans have a low albedo. The Earth’s planetary albedo varies mainly through varying cloudiness, snow, ice, leaf area and land cover changes. (RS)
Albedo Modification—Alternative term for solar geoengineering
Anthropocene—The current geological age, in which humankind is the dominant influence on the climate and environment
Anthropogenic—Caused or produced by humans. (RS)
Bioenergy with Carbon Capture and Storage (BECCS)—A form of carbon removal, in which large tracts of land grow plants for fuel, and where CO2 emitted from their combustion is captured and stored underground. (Also known as: Bioenergy with CO2 capture and sequestration, BECS)
Biochar—A form of carbon removal, where charcoal produced from plant matter is stored in the soil.
Biodiversity—The total diversity of all organisms and ecosystems at various spatial scales (from genes to entire biomes). (RS)
Biofuel—A fuel produced from organic matter or combustible oils produced by plants. Examples of biofuel include alcohol, black liquor from the paper-manufacturing process, wood, and soy-bean oil. (RS)
Biological pump—The process by which CO2 fixed by photosynthesis is transferred to the deep ocean as dead organisms, skeletal and fecal material resulting in storage of carbon for periods of decades to centuries or even permanently in the sediment.(RS)
Carbon removal, Carbon dioxide removal (CDR), Carbon geoengineering—Techniques which remove CO2 from the atmosphere, thus addressing the primary cause of anthropogenic climate change.
Carnegie Climate Geoengineering Governance Initiative (C2G2)—An international initiative to promote inclusive global governance of the research, testing and deployment of geoengineering technologies
Cirrus Cloud Thinning—A form of solar geoengineering, reducing the absorption of radiation by cirrus clouds
Chemtrails—Term used by some people to ascribe aircraft vapor trails to geoengineering secretly deployed by governments
Climate Engineering, Climate Geoengineering—Intentional large-scale human interference in the earth system to combat climate change.
Climate Intervention—Alternative term for geoengineering used in US National Academy of Science 2015 report
CO2—Carbon dioxide; greenhouse gas, and major cause of anthropogenic climate change.
Convention on Biological Diversity (CBD)—International treaty to maintain biodiversity; basis of some decisions on geoengineering governance. (CBD Conference of Parties, or COP, is its decision-making body)
Direct Air Capture (DAC)—Form of carbon removal, using chemical processes to capture CO2 from the atmosphere.
Distributive justice—Ethical approach to ensure the just allocation of costs and benefits (of geoengineering), seeks to avoid incidental inequalities in outcome.
Earth system—An approach to ecology which sees the earth as an amalgamation of multiple related dynamic systems
EMICS—Earth system Models of Intermediate Complexity.
ENMOD—1977 Convention on the prohibition of military or any other hostile use of environmental modification techniques.
Forum for Climate Engineering Assessment (FCEA)—Initiative of the School of International Service at American University in Washington DC, to assess the social, ethical, political, and legal implications of geoengineering
Geoengineering—Intentional large-scale human interference in the earth system to combat climate change.
Geoengineering Governance—The application of laws, norms, and international agreements to manage the research, testing and deployment of geoengineering technologies. Governance also includes decision making, including the participation of different stakeholders and their access to relevant information.
Geoethics—The branch of ethics which relates to the interaction of human activity with our physical world in general, and with the practice of the Earth sciences in particular.
GESAMP—Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP); advises the UN system on the marine environmental protection.
Global thermostat—A metaphor to describe the need to decide on how much reduction in warming should be achieved from the solar geoengineering
Greenhouse Gases (GHGs)—Atmospheric gases of natural and anthropogenic origin that absorb and emit radiation at specific wavelengths within the spectrum of thermal infrared radiation emitted by the Earth’s surface, the atmosphere itself and by clouds. This property causes the greenhouse effect. (RS)
Greenhouse Gas Removal—Techniques which remove GHGs from the air, thus addressing a cause of climate change. Carbon removal is one kind of Greenhouse Gas Removal.
Intergenerational justice—Balancing the needs of current and future generations
Intergovernmental Panel on Climate Change (IPCC)—Intergovernmental scientific body set up by the UN to provide policy-relevant information on latest scientific knowledge on climate change and its political and economic impact
London Convention/London Protocol—International treaty which also governs certain forms of marine geoengineering, such as ocean fertilization
Marine Cloud Brightening (MCB)—A form of solar geoengineering which makes clouds brighter to increase planetary albedo
Moral Hazard argument—The idea that by introducing alternative technologies to address the causes and effects of climate change, the impetus to tackle it through reducing greenhouse gas emissions is lessened.
Mount Pinatubo—Volcano in the Philippines whose eruption in 1991 lowered global temperatures, providing evidence for prospective solar geoengineering technologies
NDCs (Nationally Determined Contributions)—Government commitments to reduce greenhouse gas emissions under Paris Agreement of the UNFCCC process.
Negative Emissions Technologies (NETs)—Alternative term for greenhouse gas removal (including carbon removal) used by IPCC
Ocean acidification—A decrease in the pH of sea water due to the uptake of anthropogenic carbon dioxide. (RS)
Ocean fertilization—Introduction of nutrients (such as iron) to the upper ocean to increase growth of algae or phytoplankton, thereby acting as a carbon sink to reduce atmospheric CO2.
Overshoot—The amount by which global temperatures, will rise above international targets.
Paris Agreement—2015 global treaty to limit average global temperature rise to within 1.5–2° C above the pre-industrial level.
Procedural justice—The idea of fairness in the processes (governing geoengineering) that resolve disputes and allocate resources.
Radiative Forcing (RF)—Radiative forcing is the change in the net irradiance at the tropopause due to a change in an external driver of climate change, such as, for example, a change in the concentration of carbon dioxide or the output of the sun. (RS)[Negative forcing implies more energy is sent back than is received, creating a cooling effect.]
SCoPEx—Stratospheric Controlled Perturbation Experiment—Experiment to advance understanding of stratospheric aerosols that could be relevant to solar geoengineering.
Slippery Slope—The concept that a course of action, once embarked upon is, hard to reverse, and tends to reinforce itself.
Solar Geoengineering, Solar Radiation Management (SRM)—Techniques to reflect more solar radiation into space, reducing temperatures and addressing a symptom (but not cause) of climate change
Solar Radiation Management Governance Initiative (SRMGI)—International, NGO-driven project that seeks to expand the global conversation around the governance of solar geoengineering research.
Space mirrors—A proposed form of solar geoengineering in which wire mesh mirrors would be placed in low orbit to reflect solar radiation.
Stratosphere—The secondary layer of the atmosphere, above the troposphere, extending from about 10 km to about 50 km, where some forms of solar geoengineering are proposed to be deployed.
Stratospheric Aerosol Injection (SAI)—A form of solar geoengineering, involving the introduction of aerosols into the stratosphere to reflect solar radiation and lower temperatures.
Sustainable Development Goals (SDGs)—International goals agreed in 2015 to end poverty, protect the planet, and ensure prosperity for all as part of a new sustainable development agenda, to be achieved by 2030.
Termination Risk—The idea that premature termination of solar geoengineering could create a sudden shift in temperatures back to what it would have been without solar geoengineering, which could have catastrophic impacts.
Tropopause—Boundary between the troposphere and the stratosphere
Troposphere—Lowest level of atmosphere, where weather happens, extending from earth’s surface to around 10km.
UN Environment (formerly UN Environment Programme, UNEP)—UN agency promoting the environmental dimension of sustainable development.
United Nations Framework Convention on Climate Change (UNFCCC)—197-member parent treaty of 2015 Paris climate change agreement. (UNFCCC Conference of Parties or COP is chief decision making body; COP 23 takes place in 2017, COP 24 in 2018)
World Meteorological Organization (WMO)—UN system’s authoritative voice on the state and behavior of the Earth’s atmosphere, its interaction with the oceans, the climate and the resulting distribution of water resources.
Definitions marked (RS) drew on the glossary from Royal Society: Geoengineering the climate: Science, governance and uncertainty, September 2009