You can't, It means you will not be able to use dimmer switches.
This is being done by the Government as part of Tony Blair's battle against 'weather of mass destruction' i.e. the mythical climate change.
Be prepared for much higher taxes and many more draconian impositions on your normal lifestyle. Because the Government have realised that climate change can be a very lucrative, cash cow and another way for bureaucratic control freaks to interfere in the lives of ordinary, law abiding citizens they are falling over backwards to support the pseudo-scientific rantings of the eco-fanatics.
So, greenhouse is all about carbon dioxide, right?
Wrong. The most important players on the greenhouse stage are water vapor and clouds. Carbon dioxide has been increased to about 0.038% of the atmosphere (possibly from about 0.028% pre-Industrial Revolution) while water in its various forms ranges from 0% to 4% of the atmosphere and its properties vary by what form it is in and even at what altitude it is found in the atmosphere. In simple terms, however, the bulk of Earth's greenhouse effect is due to water vapor by virtue of its abundance. Water accounts for about 90% of the Earth's greenhouse effect -- perhaps 70% is due to water vapor and about 20% due to clouds (mostly water droplets), some estimates put water as high as 95% of Earth's total greenhouse effect. The remaining portion comes from carbon dioxide, nitrous oxide, methane, ozone and miscellaneous other "minor greenhouse gases." As an example of the relative importance of water it should be noted that changes in the relative humidity on the order of 1.3-4% are equivalent to the effect of doubling CO2.
Well, I heard that carbon dioxide is bad -- it's pollution, isn't it?
There seem to be a few things that your informant forgot to tell you -- like carbon dioxide being an essential trace gas that underpins the bulk of the global food web. Estimates vary, but somewhere around 15% seems to be the common number cited for the increase in global food crop yields due to aerial fertilization with increased carbon dioxide since 1950. This increase has both helped avoid a Malthusian disaster and preserved or returned enormous tracts of marginal land as wildlife habitat that would otherwise have had to be put under the plow in an attempt to feed the growing global population. Commercial growers deliberately generate CO2 and increase its levels in agricultural greenhouses to between 700ppmv and 1,000ppmv to increase productivity and improve the water efficiency of food crops far beyond those in the somewhat carbon-starved open atmosphere. CO2 feeds the forests, grows more usable lumber in timber lots meaning there is less pressure to cut old growth or push into "natural" wildlife habitat, makes plants more water efficient helping to beat back the encroaching deserts in Africa and Asia and generally increases bio-productivity. If it's "pollution," then it's pollution the natural world exploits extremely well and to great profit. Doesn't sound too bad to us.
But we're responsible for all the carbon dioxide greenhouse effect?
Gracious no! Humans can only claim responsibility, if that's the word, for abut 3.4% of carbon dioxide emitted to the atmosphere annually, the rest of it is all natural (you can see the IPCC representation of the natural carbon cycle and human perturbation here or a simple schematic from Woods Hole here). Half our estimated emissions fail to accumulate in the atmosphere," "disappearing" into sinks as yet undetermined. Humans' total accumulated carbon contribution could account for perhaps 25% of the total non-water greenhouse gases (that is, accounting for all the increase since the Industrial Revolution regardless of source and irrespective of whether warming from any cause might result in an increase in natural emission to atmosphere -- we're simply claiming the lot as anthropogenic or human-caused here).
Clarification June 4: the mention of 25% of total non-water greenhouse effect above and the following mention of 2.5% of total greenhouse effect has confused a few readers, leading to some e-mails suspecting one or the other to be a typographical error. The figures are correct. Recall that water vapor accounts for about 70% and clouds (mostly water droplets) accounts for another 20%, thus water in it's various forms is 90% of the greenhouse effect, leaving 10% for non-water greenhouse effect. Of this remaining 10%, mainly atmospheric carbon, humans might be responsible for 25% of the total accumulated atmospheric carbon, thus 0.25 x 0.1 = 0.025 x 100 = 2.5% of the total greenhouse effect.
Ah, we've added 2.5% to the total greenhouse effect then?
Not exactly, if it were such a simple accumulation, we could easily determine exactly how much Earth would warm from a doubling of atmospheric CO2 (not much) and certainly that would be an improvement on the silly figures bandied about. Theoretically, in a dry atmosphere, carbon dioxide could absorb about three times more energy than it actually does, as could clouds in the absence of all other greenhouse gases -- look at it as there already being "competition" for available suitable longwave radiation (energy these gases can absorb), if you like. Readers should be aware that the temperature effect of atmospheric carbon dioxide is logarithmic (that means there is a diminishing response as you keep adding more, like the additional window shade example, above). If we consider the warming effect of the pre-Industrial Revolution atmospheric carbon dioxide (about 280 parts per million by volume or ppmv) as 1, then the first half of that heating was delivered by about 20ppmv (0.002% of atmosphere) while the second half required an additional 260ppmv (0.026%). To double the pre-Industrial Revolution warming from CO2 alone would require about 90,000ppmv (9%) but we'd never see it - CO2 becomes toxic at around 6,000ppmv (0.6%, although humans have absolutely no prospect of achieving such concentrations).
f that's all the anticipated greenhouse effect, where do the big warming estimates come from?
Ah, this is where it gets rather contentious because the big warming numbers come not from measurements but from computer models. These computer models and their output are passionately defended by the modeling clique and frequently derided by empiricists -- but the bottom line is that models make an enormous range of assumptions. Whether all the assumptions, tweaks and parameter adjustments really collectively add up to a realistic representation of the atmosphere is open to some conjecture (current climate models do not model "natural" climatic variation very well), but there is no evidence yet that they can predict the future with any greater certainty than a pack of Tarot cards. Moreover, humans do a lot besides emitting greenhouse gases, changing vegetation and transpiration rates through agriculture, for example, and many effects expected to both increase and decrease regional temperatures are not included in these models.
Regardless, climate models are made interesting by the inclusion of "positive feedbacks" (multiplier effects) so that a small temperature increment expected from increasing atmospheric carbon dioxide invokes large increases in water vapor, which seem to produce exponential rather than logarithmic temperature response in the models. It appears to have become something of a game to see who can add in the most creative feedback mechanisms to produce the scariest warming scenarios from their models but there remains no evidence the planet includes any such effects or behaves in a similar manner.
2006-11-06 03:55:31
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answer #1
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answered by A.M.D.G 6
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