global warming

Originally posted by xs
Yes, we are productive.
And we produce less co2 thru natural respiration!

If we are in a warming trend beacause of the sun, increased geolical activity or whatever, it makes great sense to not add to the problem by spewing out greenhouse gasses.
I'm NOT convinced that things like the recent tsunami don't contribute to global warming, even if there is no known mechanism to transfer that energy to the atmosphere. Likewise increased volcanic activity on the sea floor under where the El Nino originates is said to have no bearing, but I have to doubt it-it's a huge release of energy that doesn't just disappear.
That's my story and I'm sticking to it.

people like to mis/quote wiki on this at their leisure ... so i thought i would just ctrlc and paste here just for fun ... from ... http://en.wikipedia.org/wiki/Global_warming

Global warming
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Global mean surface temperatures 1856 to 2004
Mean temperature anomalies during the period 1995 to 2004 with respect to the average temperatures from 1940 to 1980Global warming is an increase in the average temperature of the Earth's atmosphere and oceans. The term is also used for the scientific theory of anthropogenic global warming, which attributes much of the recently observed and projected global warming to a human-induced intensification of the greenhouse effect. On this theory, the increased volumes of carbon dioxide and other greenhouse gases released mainly by the burning of fossil fuels, and, to a lesser extent, land clearing and agriculture, are the primary sources of warming. The natural greenhouse effect keeps the Earth 30 °C warmer than it otherwise would be; adding carbon dioxide to an atmosphere, with no other changes, will make a planet's surface warmer. Current research is attempting to find out more details about the processes and factors that would affect a temperature increase especially about positive and negative feedback mechanisms, to allow a more precise quantification of the effects of global warming.

Temperature change is just one aspect of the broader subject of (human-induced) climate change. The scientific opinion on climate change, as expressed by the UN Intergovernmental Panel on Climate Change (IPCC) and explicitly endorsed by the national science academies of the G8 nations, is that the average global temperature has risen 0.6 ± 0.2 °C since the late 19th century, and that it is likely that "most of the warming observed over the last 50 years is attributable to human activities" [1]. A small minority of qualified scientists contest the view that humanity's actions have played a significant role in increasing recent temperatures. Uncertainties do exist regarding how much climate change should be expected in the future, and a hotly contested political and public debate exists over what actions, if any, should be taken in light of global warming.

Based on basic science, observational sensitivity studies, and the climate models referenced by the IPCC, temperatures may increase by 1.4 to 5.8 °C between 1990 and 2100 [2]. This is expected to result in other climate changes including rises in sea level and changes in the amount and pattern of precipitation. Such changes may increase the frequency of extreme weather events such as floods, droughts, heat waves, and hurricanes, change agricultural yields, or contribute to biological extinctions. Although warming is expected to affect the number and magnitude of these events, it is very difficult to connect any particular event to global warming.

Contents [hide]
1 Overview
2 Warming of the Earth
3 Causes of global warming
3.1 Greenhouse gas emissions
3.2 Alternative theories
3.2.1 Solar variation theory
3.2.2 Other theories
4 Climate models
5 Issues
5.1 The relation between global warming and ozone depletion
5.2 The relation between global warming and global dimming
5.3 Pre-human global warming
6 Public controversy
7 Effects
7.1 Effects on ecosystems
7.2 Destabilisation of ocean currents
7.3 Environmental refugees
7.4 Spread of disease
7.5 Financial effects
7.6 Possible beneficial effects
8 Mitigating and adapting to global warming
9 References
10 See also
11 External links
11.1 Scientific
11.2 Other



[edit]
Overview
Terminology

'Global warming' is a specific case of the more general term 'climate change' (which can also refer to cooling, such as in Ice ages). Furthermore, the term is in principle neutral as to the causes, but in common usage, 'global warming' generally implies a human influence. Note, however, that the UNFCCC uses 'climate change' for human caused change and 'climate variability' for non-human caused change [3]. Some organizations use the term 'anthropogenic climate change' for human induced changes.

See also: Glossary of climate change
The scientific consensus on global warming is that the Earth is warming, and that humanity's greenhouse gas emissions are making a significant contribution. This consensus is summarized by the findings of the Intergovernmental Panel on Climate Change (IPCC). In the Third Assessment Report, the IPCC concluded that "most of the warming observed over the last 50 years is attributable to human activities". This position was recently supported by an international group of science academies from the G8 countries and Brazil, China and India [4].

Over the past century or so the global (land and sea) temperature has increased by 0.6 ± 0.2 °C [5]. The effects of global warming are increasingly visible. At the same time, atmospheric carbon dioxide has increased from around 280 parts per million (by volume) in 1800 to around 315 in 1958 and 367 in 2000, a 31% increase over 200 years. Other greenhouse gas emissions have also increased. Future carbon dioxide levels are expected to continue rising due to ongoing fossil fuel usage, though the actual trajectory will depend on uncertain economic, sociological, technological, and natural developments. The IPCC SRES gives a wide range of future carbon dioxide scenarios [6], ranging from 540 to 970 parts per million by 2100.

Climate models, driven by estimates of increasing carbon dioxide and to a lesser extent by generally decreasing sulphate aerosols, predict temperatures will increase by between 1.4 and 5.8 °C in the period 1990 to 2100 [7]). Much of this uncertainty results from not knowing future carbon dioxide emissions, but there is also uncertainty about the accuracy of climate models. Climate commitment studies predict that, even if levels of greenhouse gases and solar activity were to remain constant, the global climate is committed to 0.5 °C of warming (some model results are as high as 1.0 °C) over the next one hundred years due to the lag in warming caused by the oceans.

Although the combination of scientific consensus and economic incentives were enough to persuade the governments of more than 150 countries to ratify the Kyoto Protocol, there are issues about just how much greenhouse gas emissions warm the planet. Some politicians (such as American president George W. Bush [8] and Australian Prime Minister John Howard [9]) and public intellectuals (such as Bjørn Lomborg [10] and Ronald Bailey [11]), have argued the cost of mitigating global warming is too large to be justified. However, some segments of the business community have accepted both the reality of anthropogenic global warming and the need for actions such as carbon emissions trading and carbon taxes.

[edit]
Warming of the Earth

Two millenia of temperatures according to different reconstructions, each smoothed on a decadal scale. The unsmoothed, annual value for 2004 is also plotted for reference.Relative to 1860-1900 the global (land and sea) temperature has increased by 0.75 °C. Temperatures in the lower troposphere have increased between 0.12 and 0.22 °C per decade since 1979. Over the past one or two thousand years before 1850, world temperature is believed to have been relatively stable, with various (possibly local) fluctuations, such as the Medieval Warm Period or the Little Ice Age.

The length of time over which one is interested in change may vary according to the focus of the user of the term and the datasets available for investigation. Temperature record holds a discussion of the various records. An approximately global instrumental temperature record begins in about 1860; contamination from the urban heat island is believed to be small. A longer-term perspective is available from various proxy records for recent millenia; see Temperature record of the past 1000 years for a discussion of these records and their differences. Attribution of recent climate change is clearest for the most recent period (the last 50 years) for which the most detailed data is available. Satellite temperature measurements of the tropospheric temperature date from 1979.

[edit]
Causes of global warming
Main articles: attribution of recent climate change, and scientific opinion on climate change, and [[{{{3}}}]], and [[{{{4}}}]], and [[{{{5}}}]]

Carbon dioxide during the last 400,000 years and the rapid rise since the Industrial RevolutionThe climate system varies both through natural, "internal" processes as well as in response to variations in external "forcing" from both human and non-human causes, including changes in the Earth's orbit around the Sun (Milankovitch cycles), solar activity, and volcanic emissions as well as greenhouse gases. Climatologists accept that the earth has warmed recently but the cause or causes of this change is somewhat more controversial, especially outside the scientific community.

Atmospheric scientists know that adding carbon dioxide (CO2) or methane (CH4) to an atmosphere, with no other changes, will tend to make a planet's surface warmer. Indeed, greenhouse gases create a natural greenhouse effect without which temperatures on Earth would be an estimated 30 °C lower, and the Earth uninhabitable. It is therefore not correct to say that there is a debate between those who "believe in" and "oppose" the theory that adding carbon dioxide or CH4 to the Earth's atmosphere will result in warmer surface temperatures on Earth, on average. Rather, the debate is about what the net effect of the addition of carbon dioxide and CH4 will be.

[edit]
Greenhouse gas emissions

Greenhouse gas trendsCoal-burning power plants, automobile exhausts, factory smokestacks, and other waste vents of the human environment contribute about 22 billion tons of carbon dioxide and o...

If anyone ever saw "The Day After Tomorrow", is something like that possible? A complete climate change?

Originally posted by PocketKings
If anyone ever saw "The Day After Tomorrow", is something like that possible? A complete climate change?

Originally posted by DeepThought
Not at the rate that it did in the film. The change could be rapid in the sense of a couple of decades.

Ice cap melting is diluting the northern oceans, the drop in salinity puts a block on the gulf stream, as the cooling stream can't sink. When it switches off Northern Europe is in for some very cold winters, advancing glaciers and so on. This tak ...[text shortened]... . The process will take a couple of decades. Britain can expect some very harsh winters then.