Climate change glossary
EHow does adaptation differ from mitigation? And what is REDD? The jargon of climate change can be hard to grasp. Use this glossary to decode it.
Emission Trading Scheme (ETS) A scheme set up to allow the trading of emissions permits between business and/or countries as part of a cap and trade approach to limiting greenhouse gas emissions. The best-developed example is the EU's trading scheme, launched in 2005. See Cap and trade.
EU Burden-sharing agreement A political agreement that was reached to help the EU reach its emission reduction targets under the Kyoto Protocol (a reduction of 8% during the period 2008-2012, on average, compared with 1990 levels). The 1998 agreement divided the burden unequally amongst member states, taking into account national conditions, including greenhouse gas emissions at the time, the opportunity for reducing them, and countries' levels of economic development.
F
Feedback loop In a feedback loop, rising temperatures on the Earth change the environment in ways that affect the rate of warming. Feedback loops can be positive (adding to the rate of warming), or negative (reducing it). The melting of Arctic ice provides an example of a positive feedback process. As the ice on the surface of the Arctic Ocean melts away, there is a smaller area of white ice to reflect the Sun's heat back into space and more open, dark water to absorb it. The less ice there is, the more the water heats up, and the faster the remaining ice melts.
Flexible mechanism Instruments that help countries and companies meet emission reduction targets by paying others to reduce emissions for them. The mechanism in widest use is emissions trading, where companies or countries buy and sell permits to pollute. The Kyoto Protocol establishes two flexible mechanisms enabling rich countries to fund emission reduction projects in developing countries - Joint Implementation (JI) and the Clean Development Mechanism (CDM).
Fossil fuels Natural resources, such as coal, oil and natural gas, containing hydrocarbons. These fuels are formed in the Earth over millions of years and produce carbon dioxide when burnt.
G
G77 The main negotiating bloc for developing countries, allied with China (G77+China). The G77 comprises 130 countries, including India and Brazil, most African countries, the grouping of small island states (Aosis), the Gulf states and many others, from Afghanistan to Zimbabwe.
Geological sequestration The injection of carbon dioxide into underground geological formations. When CO2 is injected into declining oil fields it can help to recover more of the oil.
Global average temperature The mean surface temperature of the Earth measured from three main sources: satellites, monthly readings from a network of over 3,000 surface temperature observation stations and sea surface temperature measurements taken mainly from the fleet of merchant ships, naval ships and data buoys.
Global energy budget The balance between the Earth's incoming and outgoing energy. The current global climate system must adjust to rising greenhouse gas levels and, in the very long term, the Earth must get rid of energy at the same rate at which it receives energy from the sun.
Global dimming An observed widespread reduction in sunlight at the surface of the Earth, which varies significantly between regions. The most likely cause of global dimming is an interaction between sunlight and microscopic aerosol particles from human activities. In some regions, such as Europe, global dimming no longer occurs, thanks to clean air regulations.
Global warming The steady rise in global average temperature in recent decades, which experts believe is largely caused by man-made greenhouse gas emissions. The long-term trend continues upwards, they suggest, even though the warmest year on record, according to the UK's Met Office, is 1998.
Global Warming Potential (GWP) A measure of a greenhouse gas's ability to absorb heat and warm the atmosphere over a given time period. It is measured relative to a similar mass of carbon dioxide, which has a GWP of 1.0. So, for example, methane has a GWP of 25 over 100 years, the metric used in the Kyoto Protocol. It is important to know the timescale, as gases are removed from the atmosphere at different rates.
Greenhouse gases (GHGs) Natural and industrial gases that trap heat from the Earth and warm the surface. The Kyoto Protocol restricts emissions of six greenhouse gases: natural (carbon dioxide, nitrous oxide, and methane) and industrial (perfluorocarbons, hydrofluorocarbons, and sulphur hexafluoride).
Greenhouse effect The insulating effect of certain gases in the atmosphere, which allow solar radiation to warm the earth and then prevent some of the heat from escaping. See also Natural greenhouse effect.
H
Hockey stick The name given to a graph published in 1998 plotting the average temperature in the Northern hemisphere over the last 1,000 years. The line remains roughly flat until the last 100 years, when it bends sharply upwards. The graph has been cited as evidence to support the idea that global warming is a man-made phenomenon, but some scientists have challenged the data and methodology used to estimate historical temperatures. (It is also known as MBH98 after its creators, Michael E. Mann, Raymond S. Bradley and Malcolm K. Hughes.)
I
IPCC The Intergovernmental Panel on Climate Change is a scientific body established by the United Nations Environment Programme and the World Meteorological Organization. It reviews and assesses the most recent scientific, technical, and socio-economic work relevant to climate change, but does not carry out its own research. The IPCC was honoured with the 2007 Nobel Peace Prize.
J
Joint implementation (JI) An agreement between two parties whereby one party struggling to meet its emission reductions under the Kyoto Protocol earns emission reduction units from another party's emission removal project. The JI is a flexible and cost-efficient way of fulfilling Kyoto agreements while also encouraging foreign investment and technology transfer.
