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Sometimes it can be difficult to know what people mean when they use certain 'buzzwords' - here we try to simplify things with some commonly used phrases.
The carbon cycle Read more... Carbon dioxide (CO2) is the main greenhouse gas of concern. A finite amount of carbon is stored in the sea, the atmosphere, in living matter and in fossil fuels (oil, gas and coal). Without human influence, transfers between these stores roughly balance each other. For example, plants absorb carbon as they grow, but release it as they decay. But when humans cut down trees or burn fossil fuels, they release extra carbon into the atmosphere, increasing the greenhouse effect.
To understand climate change, we must distinguish between weather and climate. “Weather” changes constantly and relates to the local temperatures, winds and precipitation (rain, hail, sleet and snow) that we experience every day. “Climate” refers to the patterns (over long periods of time, typically 30 years) of average weather and its variations and extremes across different regions of the earth.
The earth’s climate has changed many times in response to natural causes. These include interactions between the ocean and the atmosphere, changes in the earth's orbit and volcanic eruptions. However the term “climate change” usually refers to changes which have occurred since the early 1900s, when the climatic effects of the global industrialisation of human society began to be seen.
Climate change mitigation and adaptation Read more... The language of climate science includes two key concepts: mitigation and adaptation. “Mitigating” climate change describes actions taken to limit emissions of greenhouse gases into the atmosphere which result from human activity. “Adapting” to climate change describes actions taken to prepare ourselves for those impacts of climate change which can not now be avoided.
Energy Descent Action Plan. Read more... An Energy Descent Action Plan (EDAP) is a local plan for dealing with Peak Oil. It goes well beyond issues of energy supply, to look at across-the-board creative adaptations in the realms of health, education, economy and much more. An EDAP is a way to think ahead, to plan in an integrated, multidisciplinary way, to provide direction to local government, decision makers, groups and individuals with an interest in making the place they live into a vibrant and viable community in a post-carbon era. Source: http://www.eatthesuburbs.org/edap-primer/
Feedback effects Read more... Higher average temperatures can have both negative and positive consequences. Some processes are triggered which release yet more greenhouse gases and speed further warming, whilst other processes counter it. For example, if the permafrost were to melt it would release much more methane into the atmosphere than is already emitted from rice paddies and landfill sites, and add considerably to the greenhouse effect. Also, melting snow and ice cover decreases the reflective white surface area of the earth by exposing more dark, non-reflective land surface, which absorbs more heat and so speeds warming further. But, in contrast, higher temperatures also increase the growth rate of plants so that they increase their intake of CO2, and so act as temporary carbon “sinks”, or stores. (This natural carbon storage is why it is so important to prevention deforestation). The balance between negative and positive feedbacks is a major cause of uncertainty in climate predictions. But uncertainty about the specific effects of global warming does not imply uncertainty about global warming itself.
The greenhouse effect
“Greenhouses gases” (such as water vapour, methane and carbon dioxide) in the earth’s atmosphere are emitted by natural processes on earth and are essential for life. They form an insulating layer around the planet which traps warmth from the sun and prevents the earth from being frozen and lifeless. They are known as greenhouse gases because of this warming effect.
Human activities (such as industry and agriculture) influence global climate by releasing more greenhouse gases into the atmosphere. These gases then stop more of the sun’s warmth from escaping into space, increasing global temperatures.
Peak Oil. Read more... • Peak Oil refers to the maximum extraction rate of oil, after which the rate of extraction will decline. Source: http://www.transitionculture.org/essential-info/what-is-peak-oil/
The United Nations Intergovernmental Panel on Climate Change (IPCC) Read more... The IPCC (established by the United Nations and the World Meteorological Organisation) is the world’s leading scientific body for the assessment of climate change. It has been reviewing worldwide research on climate change by thousands of mainstream scientists since 1988. The IPCC advises the United Nations and governments around the world, and its reports inform international negotiations about climate change agreements such as the Copenhagen Accord. The IPCC was awarded the Nobel Peace Prize in 2007. In its latest report, the IPCC concluded that:- Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level. (IPCC Fourth Assessment Report (AR4), November 2007) The IPCC also concludes that human activities which strengthen the greenhouse effect are the main cause of the warming observed over the last 100 years, particularly over the last 50 years. Over 30 billion tonnes of CO2 are emitted globally each year by burning fossil fuels, and another 7 billion tonnes by changes in land use, mainly deforestation. These gases are now concentrated in the atmosphere at levels not seen for at least the past 650,000 years. The IPCC suggests that global temperatures are likely to rise between 1.1 and 6.4 degrees above 1990 levels by 2100, depending on our emissions. This could result in a rise in global sea levels of between 20 and 60cm, continued melting of ice caps, glaciers and sea ice, changes in precipitation patterns and the intensification of storms.