Feedback refers to the modification of a process by changes resulting from the process itself. Positive feedbacks accelerate the process, while negative feedbacks slow it down. Part of the uncertainty around future climates relates to important feedbacks between different parts of the climate system: air temperatures, ice and snow albedo (reflection of the sun’s rays), and clouds. An important positive feedback is the ice and snow albedo feedback...

There are three main factors that directly influence the energy balance of the earth: the total energy influx, which depends on the earth's distance from the sun and on solar activity; the chemical composition of the atmosphere, and albedo, the ability of the earth's surface to reflect light. The only factor that has changed significantly in the last 100 years is the chemical composition of the atmosphere. This resource also includes a graphic th...

Since pre-industrial times, the atmospheric concentration of methane (CH4) has increased by 150%. Methane is a greenhouse gas that has a global warming potential that is 23 times stronger than CO2. (IPCC 2001) In 2000 the total world CH4 emissions was estimated at 6,000 million tonnes of CO2equivalents. In South America the emissions of CH4 per capita is almost twice the world average, while the per capita emissions in Central America and Caribb...

Large tropical hydropower reservoirs in Latin America may have a potential adverse impact on the climatic system through releasing greenhouse gases into the atmosphere. Submerging large areas of land and tropical vegetation under water and fluctuations in water level promote physical-chemical processes that decompose the organic matter and generate methane and carbon dioxide emissions. In the initial years of operation, emission levels are especi...

Shows the main producers of CH4 from countries in Latin America and the Caribbean and the source of the emissions. Brazil, a leading cattle-ranching country, has the highest methane emission level in the region and is one of the world’s biggest emitters of methane (CH4). Most of the methane emissions in the region are generated by agriculture.

Landfi ling is the most common waste management practice, and results in the release of methane from the anaerobic decomposition of organic materials. Methane is around 20 times more potent as a GHG than carbon dioxide. If the disposal of organic matter were to be decreased (for example by composting or incineration) it would be possible to reduce the amount of methane emissions. However, landfill methane is also a source of energy, and some lan...

The disposal and treatment of waste can produce emissions of several greenhouse gases (GHGs), which contribute to global climate change. The most significant GHG gas produced from waste is methane. It is released during the breakdown of organic matter in landfills. Other forms of waste disposal also produce GHGs but these are mainly in the form of carbon dioxide (a less powerful GHG). Even the recycling of waste produces some emissions (although ...

The disposal and treatment of waste can produce emissions of several greenhouse gases (GHGs), which contribute to global climate change. The most significant GHG gas produced from waste is methane. It is released during the breakdown of organic matter in landfills. Other forms of waste disposal also produce GHGs but these are mainly in the form of carbon dioxide (a less powerful GHG). Even the recycling of waste produces some emissions (although ...

Buildings (residential and commercial) account for 10 to 15% of all greenhouse gas emissions, including almost 70% carbon dioxide and 25% methane.

The graph shows emissions of methane in Norway from 1985 to 2010. It makes an estimate to 2010 according to the 1998-2001 long term program. Fossil fules, live stock and waste dumps are among the anthropogenic sources that create methane

The graph shows Norwegian emissions of methane from 1985 to 1996. Methane is emitted to the atmosphere by both natural and anthropogenic sources. Among these are fossil fuels, waste dumps, and livestock.

With a doubling of atmospheric CO2, it is likely that there will be increases in the thickness of the active layer permafrost and the disappearance of most of the ice-rich discontinous permafrost over a century-long time span. This figure provides a good example of changes already observed in Alaska. Widespread loss of discontinous permafrost will trigger erosion or subsidence of ice-rich landscapes, change hydrologic processes, and release CO2 ...

The table lists some of the main greenhouse gases (such as carbon dioxide, methane, and freons) and their concentrations in pre-industrial times and in 1994; atmospheric lifetimes; anthropogenic sources; and Global Warming Potential. Greenhouse gases are a key factor in global warming, as they trap the radiating heat in the atmosphere, reflecting it back to the atmosphere.

Since pre-industrial times, the atmospheric concentration of greenhouse gases has grown significantly. Carbon dioxide (CO2) concentration has increased by about 31%, methane concentration by about 150%, and nitrous oxide concentration by about 16% (Watson et al 2001). The present level of carbon dioxide concentration (around 375 parts per million) is the highest for 420,000 years, and probably the highest for the past 20 million years.

A table of the main greenhouse gases and their attributes, sources and concentration levels from 1998. Naturally occurring greenhouse gases include water vapour, carbon dioxide, methane, nitrous oxide, and ozone. Greenhouse gases that are not naturally occurring include hydro-fl uorocarbons (HFCs), perfl uorocarbons (PFCs), and sulphur hexafl uoride (SF6), which are generated in a variety of industrial processes. Water vapour is the most abunda...

Shows various countries and their levels of CO2 emissions per capita. Also indicates the difference from high income to low income nations on CO2 output. Central to any study of climate change is the development of an emissions inventory that identifies and quantifies a country’s primary anthropogenic sources and sinks of greenhouse gas. Emissions are not usually monitored directly, but are generally estimated using models. Some emissions can b...

Emissions from human activities, and primarily fossil fuels, contribute to climate change, global warming and the greenhouse effect. This is primarily from industry, energy, transportation and related sectors. Please note that this collection of graphics has since been updated, please see http://www.grida.no or http://unfccc.int/ for the latest information and graphics.

Emissions from human activities, and primarily fossil fuels, contribute to climate change, global warming and the greenhouse effect. This is primarily from industry, energy, transportation and related sectors. Please note that this collection of graphics has since been updated, please see http://www.grida.no or http://unfccc.int/ for the latest information and graphics.

Emissions from human activities, and primarily fossil fuels, contribute to climate change, global warming and the greenhouse effect. This is primarily from industry, energy, transportation and related sectors. Please note that this collection of graphics has since been updated, please see http://www.grida.no or http://unfccc.int/ for the latest information and graphics

Emissions from human activities, and primarily fossil fuels, contribute to climate change, global warming and the greenhouse effect. This is primarily from industry, energy, transportation and related sectors. Please note that this collection of graphics has since been updated, please see http://www.grida.no or http://unfccc.int/ for the latest information and graphics.