 Poster: A snowHead
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We live on the third planet from a medium sized sun. This planet is 5 billion years old and it has been changing constantly during that time. The Earth is now in it's 3rd atmosphere, the first having been helium and hydrogen which dissapated early on due to the intense heat. As the planet cooled, volcanic eruptions produced a 2nd atmosphere of steam and carbon dioxide.
Later, the water vapor condensed, forming the coceans that cover most of Earth. And so evolution went on until 2 billion years ago when ice first appeared.
For the last 700,000 years we have been in a geological ice age, characterised by advancing and retreating glacial ice. For unknown reasons, ice covers much of "our" planet every hundred thousand years with smaller advances every 20,000 years. The last advance was 20,000 years ago, so we're probably due another at some point in the not too distant.
On "our" active planet, we have 500 active volcanoes and an eruption every 2 weeks. There are 1.5 million earthquakes a year, with a Richter 5 quake every 6 hours and a big quake every 10 days! There are tsunamis that race across the Pacific every 3 months.
As for "our" atmosphere, at any point there are 1500 electrical storms raging, eleven lightening strikes a second and a tornado tearing accross the planet surface every 6 hours. Every 4 days a giant cyclonic storm, hundreds of miles in diameter, spins over the ocean and causes havoc somewhere inland.
All we can do? Run, hide and wring our hands! Anyone who believes we can stabilise our environment or atmosphere is mad. We cannot control our climate.
Is there empirical evidence of global warming - no absolutely not.
Is there empirical evidence that there is not global warming - no absolutely not.
The "evidence" of global warming is based upon computer predictions for the future and the data varies by up to 400% - hardly convincing IMHO.
Some African deserts are actually in retreat. A report in 2002 in the New Scientist reveals satelite images which prove that a swathe of land some 6000km in length has given way to new vegetation. Apparently this has been going on since the mid 80's and has largely been unreported!
The fact is we know very little about "our" planet.
How many glaciers are there in the World? And how many have been studied to conclusively state that they are all in retreat or all melting?
What about sea levels rising? They have in the north Pacific. But they've fallen in the south pacific.
So, what's this all about?
Well whilst I am not entirely happy with the way we pollute the planet and count the cost, neither am I happy with the multi-billion dollar "environmentalist" industry that expounds it's theories, perpetuating itself through the generation of fear.
RO. Thank you!
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Mark Hunter, that's a very interesting essay. I'm of pretty much the same sceptical bent!
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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Saw a documentary last night (don't think it's the one linked to below) about the 'certainty' that the active volcano on Las Palmas would eventually cause the island to split virtually in two, a huge chunk crashing into the sea. The resultant mega tsunami would initially be hundreds of metres high, and would dwarf the December tsunami, still perhaps a hundred metres or more high by the time it had crossed the Atlantic, in just five or six hours, surging up to 20 kms inland right along eastern seaboard of the USA. It's hard to conceive of the extent of the disaster!
http://www.bbc.co.uk/science/horizon/2000/mega_tsunami.shtml
We're pretty puny creatures really....
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You need to Login to know who's really who.
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So, it's best to do nothing, and once we've run out of fossil fuels, we can use something else, and who cares anyway, I'll probably be dead by then
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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Whoever said doing nothing was the answer Foxy? But the environmentalist industry has a vested interest in maintaining itself. And that makes it as dangerous as corporate industry in so much that we have no idea whether global warming is a reality. There's nothing wrong with implementing environmental controls, however. But to state that we'll leave a dreadful legacy for our children and grandchildren has no basis whatsoever in fact.
And as for burning all our fossil fuels, inevitably we'll discover cleaner alternatives. After all, we no longer rely on horses and oxen for transport and heavy duty work!
Incidentally, and scaremongers aside, many predictions are for a rise of .08 degrees C in the next 100 years. Hardly catastrophic!
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You'll need to Register first of course.
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PG, and if Yellowstone blows at the same time as Las Palmas slides, who'd be in America? 
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What about the massive asteroid strike?
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Then there's the imminent alien invasion, though possibly not before the next official end of the world.
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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I thought the world had ended at the millenium (whichever date that was)! I've been seeing a white light outside my apartment for the last 72 hours at least - I thought we were all in heaven.
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Mark Hunter,a nice summery of the global situation IMHO.That man could ever believe he could control,or affect to any significant degree, the global environment is the ultimate arrogance.As you rightly state,this planet is evolving,and will continue to do so.This takes place over a timeframe that few can conceive;and none will experience.So,it gets a bit hotter for a few years(or not)or a bit wetter(or not)or the snowline retreats(or not)Such minor events wouldn't get 1/2 a line in the history of planet Earth.Could us puny earthlings affect such events;I would take a lot of convincing.
So,what of environmental issues?Well,we should do all we can,and more,to care for and protect what we have;both for present and future generations.Not out of some fanciful notion that we are,in some way,controlling a planets climate but...........because............we live here!!!
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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A lot of you seem to have swallowed George W Bush' s view of the environment. Where is this multi-billion dollar environmentalist industry? Sorry I can't see it behind the even more multi-billion dollar oil industry. Most scientists or scientific groups who deny global warming (including Dubya's advisers) are sponsored by the oil industry.
Yes, the data and the models do vary by quite a bit, but the general scientific consensus is that global warming is happening, will continue to happen, and is influenced by man made CO2 emissions. If you take the most optimistic view we have nothing to worry about, but "do you feel lucky punk?" The consensus view, not to mention the alarmist view, should at least make us stop and think of ways of reducing our environmental impact.
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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MartinH, actually you're missing the point. The earth, the universe, everything in it, and snowHeads, was created for me! 
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You know it makes sense.
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Pete Horn, ahhhh the CO2 question......
Imagine, if you would a 100m race track. The first 78m would represent nitrogen. From there to 99m would be represented by Oxygen. Most of the remaining 1m is the inert gas Argon which would take you to about 16cm from the finish line of which 2.5cm is CO2 (about the width of the finishing line).
CO2 has increased, certainly - by about the width of a pencil. Hardly catastrophic. Concerning - maybe.
To put it another way, CO2 levels have risen in the last 50 years from 316 parts per million to 376 parts per million. A 60 parts per million increase. In global terms that is a negligible increase, especially given the history of "our" planet.
As for the multi-billion dollar environmentalist industry......
A lobby group in America "decided" with no empirical scientific data that overhead power lines were a serious threat to public health. The resultant effect of the "public concern" was a $25bn cost to run power lines in residantial areas beneath the ground. Or to put it another way an amount equal to the total GDP of 50 of the world's poorest nations.
The subsequent scientific data from tests about the nature of harmful effects from overhead powerlines concluded that there was no link to health risks. I wonder how many deaths could have been avoided had that money been spent easing 3rd world debt? A crushing verdict on the dangerous mix of science and politics?......
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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Since 1987, distinguished scientists and politicians have convened from across the world to consider historic and predictive evidence on climate change.
In 1997, the Kyoto Protocol was signed because the majority of western governments (those with most to lose by restricting economic growth) were convinced that climate change was a reality. They believe that it is (partly) artificial and that it can be controlled.
Fortunately, most people believe the evidence.
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Poster: A snowHead
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Mark Hunter, on your analogy of a 100m race track, a 376ppm concentration of CO2 would be 3.76cm not 2.5cm.
CO2 levels rose from 316ppm to 376ppm over a period of 44 years up to 2003.
CO2 is a greenhouse gas - it absorbs long wavelength infra-red radiation such as that given off by the Earth. That is why it has more effect proportionally than the other constituents of our atmosphere and why a 34% increase from the pre-industrial level of 280ppm is important.
The Earth has seen CO2 levels fluctuate in this range before (with corresponding temperature changes) but it has not seen this rate of change before. Increase in CO2 will also make rainfall more acidic. Plants will adapt to this but they are being asked to adapt at an unnaturally high rate.
The lobby group you mention may have made the American electricity industry bury its cables at a cost of billions, but this does not make the lobby group itself a billion-dollar industry. I suspect what's being talked about here is the low voltage domestic supply which has often been overhead in the US (unlike the UK) and was an eyesore into the bargain.
Under UK high voltage power lines there are some strange pockets of ill health. The scientific consensus is more research is needed. The current data neither blames or absolves high voltage power lines.
There are lobby groups in the UK campaigning against mobile phone masts and TETRA masts. There is no evidence to show these are a danger to the public, but that doesn't stop them being opposed. The groups that oppose them are small community groups with little money. Personally I believe they are misguided if they are opposing them on safety grounds, if opposing them on aesthetic grounds, or simply on the grounds of 'why should these companies not have to get planning permission like the rest of us' then I can see their point.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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This report from the Hazard Research Centre at University College London is an interesting summary, written in layman's terms, of some of the climate change research over the last four years or so. The report describes a large number of observable factors (CO2 concentrations, changes in atmospheric pollution, average temperatures, antartic ice volumes, tropospheric warming, changes to the Gulf stream, etc) all of which indicate, in empirical terms, that "global warming" is happening. The report concludes:
| Quote: |
| Evidence in support of an anthropogenic cause for contemporary climate change is now overwhelming and every few weeks further observations or new studies are published that provide added weight to the conclusions of the IPCC TAR. Global climate models remain far from definitive, however, and the range of predictions for the Earth’s climate at the end of the 21 st century and beyond continues to be wide. Such models also need to be substantially improved before they can provide a reasonably accurate picture of the regional to local scale impacts of climate change. |
As far as I'm aware the scientific and political debate has moved beyond "is global warming happening" to a vigorous discussion on what its impact will be. The strength of the "environmentalist industry" in that debate is far, far weaker than others such as governments which are hostile to the whole notion and the multinationals.
Incidently, the Hazard Research Centre at UCL (which I used to be linked to as a graduate student) also did the Las Palmas work which featured in the Horizon programme that PG mentioned.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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| David Goldsmith wrote: |
| the majority of western governments...were convinced that climate change was a reality.. |
I don't think anybody would argue that the global climate isn't changing - the point is that it's in the very nature of such systems to be unstable. The climate has always changed over various cycles and there's nothing we can do about it. Any influence human activity has had or will have is minimal (leaving aside major nuclear events).
Everyone fucusses on the changes to the temporate regions - mostly they will get warmer & wetter and that's seen as a bad thing - but there will unboubtedly be areas of the World where the 'new' climate of, say 10,000 years in the future will be much less inhospitable that it is now.
Add in the fact that continental drift will rearrange the surface of the Earth over the next few tens of millions of years and who knows where we'll be. Greenland could easily be in the South seas and a major holiday destination.
Que sera que sera, as they say.
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You need to Login to know who's really who.
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| Red Leon wrote: |
| Any influence human activity has had or will have is minimal (leaving aside major nuclear events). |
I think that there are many people who would disagree with this statement. The report I quoted above argues that there is already sufficient evidence to highlight the impact of anthropogenic-caused climate change being a reality. While this change may not be as large as the natural cycle that the earth experiences, it is argued that the climate change from man's activity will be enough to significantly affect the way in which we live on the planet (eg, in 100 years time will there be a European skiing industry, or just a handful of ultra-high, and ultra-expensive, ski resorts).
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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| Pete Horn wrote: |
| Mark Hunter, on your analogy of a 100m race track, a 376ppm concentration of CO2 is a greenhouse gas - it absorbs long wavelength infra-red radiation such as that given off by the Earth. That is why it has more effect proportionally than the other constituents of our atmosphere and why a 34% increase from the pre-industrial level of 280ppm is important. |
Water vapour, not CO2, is by far the biggest IR absorber in the atmosphere. Although burning hydrocarbons puts more of it in the atmosphere, it's a tiny proportion of what's already there, and the whole system is buffered by the vastness of the oceans. So, a 34% increase in CO2 levels produces nothing like a 34% increase in IR absorption. The environmentalists don't tell you that. I wish they would, because there may be a real threat from man-made global warming, but it's difficult to tell when facts are presented selectively.
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You'll need to Register first of course.
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| rob@rar.org.uk wrote: |
| Red Leon wrote: |
| Any influence human activity has had or will have is minimal (leaving aside major nuclear events). |
I think that there are many people who would disagree with this statement. |
Count me in. We have deforested, overgrazed, polluted water in many areas of the planet and thrown persistent gases into the atmosphere and it is definitely already having an impact. The hole in the ozone layer is real. Australians are getting skin cancers. Nature didn't put chlorofluorocarbons in the stratosphere - aerosol cans did. (And a few other things)
The amount of CO2 in the atmosphere has shot up - volcanoes and other natural sources have been relatively constant in output so the sudden increase has to come from fossil fuel burning. Why don't some accept it will have an effect on global climate? Ostrich syndrome. I happen to think global warming is real but it may yet be reversible given the previous climatic swings that have taken place without human intervention. But if we can at least reduce future CO2 emissions and maybe sequester some of the gas we have already released, then Gaia will have a better chance.
Last edited by You'll need to Register first of course. on Tue 19-04-05 11:37; edited 1 time in total
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| kuwait_ian wrote: |
| The hole in the ozone layer is real. Australians are getting skin cancers. Nature didn't put fluorocarbons in the stratosphere - aerosol cans did. |
That's something else I don't understand. Off the top of my head, 90% of the world's population lives in the Northern Hemisphere, yet the earlier and bigger hole in the ozone layer occurred over the Southern polar regions. Has anyone seen an explanation for that?
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http://www.atm.ch.cam.ac.uk/tour/part3.html Cambridge University no less has the answer. You need polar stratospheric clouds which need extreme cold to form. The Antarctic winter provides the right conditions whereas the Arctic is much warmer being oceanic.
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| Nearly all of the chlorine, and half of the bromine in the stratosphere, where most of the depletion has been observed, comes from human activities |
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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kuwait_ian, thanks for that!
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Google triumphed again - but it is a very readable explanation. Liked your contributions above, laundryman, esp the bit about water vapour.
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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| laundryman wrote: |
| So, a 34% increase in CO2 levels produces nothing like a 34% increase in IR absorption |
I didn't say that it did, only that 34% was important.
Water vapour condensed into clouds has the effect of cooling the Earth due to reflecting the Sun's heat back into space. It's one of the reasons trying to model what's going to happen is so difficult. Higher temperatures will increase evaporation of water but will that extra water in the atmosphere be as water vapour (greenhouse gas) or clouds (greenhouse effect but with lower heat inputs from the sun). How do the various effects balance out?
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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Pete Horn, I know you didn't say that - sorry if I gave the impression I was having a go at you. As for how the effects balance out, I couldn't say; I just wish that the various interested parties admitted more often that the whole topic is incredibly complex and that our understanding is limited.
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| laundryman wrote: |
| I just wish that the various interested parties admitted more often that the whole topic is incredibly complex and that our understanding is limited. |
In my experience if you go direct to the scientists doing the work (rather than the campaigning organisations) they are only too pleased to explain how complex the whole situation is. More often the problem is getting them to boil down this complexity to a more digestible picture than non-scientists can understand.
The campaigning groups, like all politicians, select the facts that best support their position, leading to the appearance that the situation has no uncertainty whatsoever. Groups on the other side of the debate then select their facts, and try to pick holes in the opposition's facts. Before you know it, the entire debate degenerates into farce, which most people except for those most passionate about it, ignore entirely. The perils of democracy...
Last edited by So if you're just off somewhere snowy come back and post a snow report of your own and we'll all love you very much  on Sun 22-05-05 22:24; edited 1 time in total
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You know it makes sense.
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rob@rar.org.uk, that about sums it up!
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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I think that this is complex but isn't it better to try and do something now to limit our ever increased burning of fossil fuels in case the bad predictions are true. I think that it is unlikely that carrying on as we currently are will ever have a beneficial outcome. I want there to be a planet there for my grandkids to enjoy and I want to be able to look them straight and say that I tried to do my bit. I have not been bothered by this in the past and I am no tree hugger but this has become very important in my thinking.
So what am I doing? I try to use my bicycle for short trips, I've switched my electricity to a green supplyer (the more people that do this the more renewable electricity will be required to be built), switched several light bulbs over to low energy ones and I make sure that I turn lights off in rooms when I'm not in them (same goes for TVs on standby etc), turned down the thermostat on my hot water tank, lowered the flow rate on my shower, reduced the timer interval on my central heating boiler. We're signed up to self scan shopping at waitrose so you get reusable bags. We've stopped using bin bags, we've made our own composter, we're building a recycling shed so we can store cans, plastics, cardboard etc. We're locally sourcing Organic Veg via a delivery scheme (excellent quality and good price). Finally I try to go easy with my right foot in my car. Stuff we are investigating is getting a new, more efficient boiler and getting solar water heating.
As you can tell I am taking this quite seriously, and I know that on my own this will make no difference whatsoever, but if everyone did at least some of what we're doing we could all meake a difference. And here's the thing, none of this has worsened our quality of life and should save us money in the bargin. If I pootle to work in my car it takes me 45 minutes. If I try and drive quickly it takes 44 minutes but I'm saving the wear and tear on my brakes, engines etc. It p***es people off because I stick to the speed limit and don't race to get there but tough. Do something now, even if it's just getting a few energy saving light bulbs or saving the odd car trip our switching electricity suppliers, or just turning things off when you are finished, or travelling to the alps by train and not by plane (plug for PG?) and these little things can all add up. I am now absolutely convinced that it just isn't worth the risk of doing nothing. There is an excellent book called "Save money and save the planet" that gives you clear ideas of things that you can do to make a difference. Do it now, please 
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Poster: A snowHead
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Okay, I accidentally closed down my browser window while my reply was virtually written so this one may be slightly less formulated than before as the motivation to do it all again is not high. Apart from the New Scientist link, I have kept all references to US & UK government organisations, with an emphasis on the US ones. The references are only there for main part of each point, there general thrust of each one is garnered from wider reading of the subject, but I'm not going to go through loads of links to compile them. A lot of the information is ultimately referenced via the IPCC report. There is an interesting alternative (as in AGW mitigating - not refution) scenario proposed by the GISS scientists which shows how important other anthropocentrically 'increased' gases are and which, while needing strong action on CH4 & CO2, suggests that (as long as it's started now), mitigation is possible.
Firstly, with regards to the affect of water vapour, this is dealt with by this climatologist who works for NASA: http://www.realclimate.org/index.php?p=142
It is worth noting that the natural greenhouse effect makes the planet habitable keeping it at roughly +15C instead of -18C (averaged out) that it would be. Therefore it could be argued that the effects of water vapour are already accounted for (see comment 2 in the above article). However the above article accounts for it much better than that, in that it shows it to be a feedback mechanism as opposed to a forcing one.
Somne other points:
1) The global atmospheric temperature is rising: http://www.giss.nasa.gov/data/update/gistemp/
2) Global average sea levels are rising, "Global mean sea level has been rising at an average rate of 1 to 2 mm/year over the past 100 years, which is significantly larger than the rate averaged over the last several thousand years.": http://www.ncdc.noaa.gov/oa/climate/globalwarming.html#Q9 It is also worth pointing out that although the rises may be localised, this can be equally catastrophic in certain areas. For example, a small rise in the sea-level at Bangladesh would cause the displacement of something like 125m people.
3) The rate of change of temperature at the moment has been shown to be higher than known, general changes in the geological record, however there are (localised) high-rate changes, i.e. at the end of a glacial period. This shows that sudden changes changes can occur in the climate - it can "flip" between two "stable" states (or atractors if you want to think of it as a chaotic system). That this can happen should be more a cause for alarm as we have implemented a net energy imbalance of about 1 W/m3, and it is imbalances that cause movements from one state to another.
4) The most recent growth in human population and rates of development have occurred during a stable period where the current rates of temperature change are unprecedented. This means that any (relatively) rapid changes of climatic state would have very profound affects on the current human situation. Life would almsot certainly survive, indeed humans would probably do so, but to pretend that the inevitable changes in global oceanographic and atmospheric patterns and their effects on agriculture, populations distribution etc. wouldn't be catastrophic, is being at least exceedingly hopeful.
http://www.ncdc.noaa.gov/paleo/pubs/crowley.html & http://www.ncdc.noaa.gov/oa/climate/globalwarming.html#Q8 & http://pubs.giss.nasa.gov/docs/2005/2005_Hansen1.pdf for both (3) & (4)
5) The amount of extra energy trapped by the extra CO2 can be calculated providing the amounts of extra CO2 are known (there are good estimates). This can be used to calculate a good estimation of the temperature changes. However, due to (a) unknowns in the future CO2 production and (b) unknowns in the feedback mechanisms, the actual temperature rises can be less predictable. The ranges are between roughly 2C and 5C. These are the most likely numbers, the range is wider but the probability distribution makes them far less likely - indeed the Hadley Centre puts the most likely changes at 3.5C - based on CO2 doubling. In some links you'll see a figure 1C used, and that is certainly possible, but more and more recent research puts the more likely limit at 2C (though the CO2, etc. production variations are the main factors involved here).
http://www.newscientist.com/popuparticle.ns?id=in23
http://www.giss.nasa.gov/research/briefs/delgenio_03/
http://www.giss.nasa.gov/research/briefs/delgenio_03/
http://pubs.giss.nasa.gov/abstracts/2004/Hansen1.html & http://pubs.giss.nasa.gov/abstracts/2004/HansenSato.html (see third ref for 3 & 4)
http://www.meto.gov.uk/research/hadleycentre/pubs/brochures/B2004/global.pdf
http://www.meto.gov.uk/research/hadleycentre/pubs/brochures/2005/CLIMATE_CHANGE_JOURNAL_150.pdf
http://www.realclimate.org/
http://www.grida.no/climate/ipcc_tar/wg1/index.htm
Finally, no one is "controlling" the atmosphere, it's more akin to hacking at an overhang with a pick-axe and saying you're controlling the rocks. I won't bother to get into a big debate on this topis after this post (it'll be pointless), I've been reading reports etc. by climate researchers and with my vast inexperience of the (complex) subject have come to agree with them (and their almost total consensus). I may however know of the odd link to an answer or paper that replies to some of the more common (or outlandish) "sceptic" points.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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| Quote: |
Is there empirical evidence of global warming - no absolutely not.
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Can we afford to take the chance??????????
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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skanky, I found the article on water vapour fascinating and informative - thanks. If I've interpreted it correctly the argument goes something like this:
(1) water vapour is by far the most important absorber of IR
(2) adding extra CO2 to the atmosphere will by itself warm the earth up a bit due to extra absorption, but the effect is not all that great because it's a relatively minor absorber
(3) however, that extra warmth causes more evaporation and hence more water vapour and a secondary (as in indirect, not necessarily smaller) increase in absorption
(4) the extra water vapour may result in more cloud which would counteract the warming effect caused by the absorption of IR radiated from the surface, because it reflects shorter wavelengths from the sun
(5) all of the calculations carry quite large uncertainties.
Is that roughly how you read it?
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You need to Login to know who's really who.
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Oh goody, this looks like fun for anyone who enjoys end of the world scenarios:-
http://www.bbc.co.uk/bbcthree/tv/end_day.shtml
It is interesting that a number of civilisation collapses have been predicated enviromental degredation - think Easter Island or the Maya. There is also a theory that the Roman empire's collapse was accellerated by either Volcano or Meteor strike causing 2 years of global cooling in the 5th century. Still France survived the little ice age with a technically much less sophisticated culture and a population of 10-15 million (much larger than the UKs at the time).
Remember that Methane is a much more powerful greenhouse gas than CO2 and results from such things as rice cultivation. What I have ttrouble seeing is how the Chinese can hope to have the same living standard as the West without massive environmental damage and a huge increase in greenhouse gases. Someone calculated that if China had the same car ownership as the UK all the worlds known oil supplied would be used within a decade.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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laundryman, sorry been in a meeting all morning.
(1) Yes. It is the main reason why the Earth surface temperature is at about +15C, one set of values of importance in percentage is WV - 60%, CO2 - 26%, Others - 14% (from a 1997 paper I had in pdf form from somewhere. I could probably find it again if pressed).
(2) Compared to the ~33C the Earth is currently watmed, the effect is not that great. However, if we take pre-industrial temperature levels and then make it the baseline, it is a lot greater - this figure shows the relative strengths of the climate forcings. Note the shortness of the error bars for combined greenhouse gases. As water vapour is a feedback mechanism it is not included.
(3) Yes.
(4) It may result in more cloud, through an increase in evaporation and therefore vapour pressure. There are two other effects to take into account. Firstly an increase in temperature means an increase in saturation vapor pressure thus more water vapour is needed to become saturated and for clouds to form, secondly there needs to be enough condensation nuclei for the water vapour to condense onto. The second one I assume won't be a problem, the first is interesting - in that both values (vapour pressure through increased evaporation and saturation vapour pressure) will go up as temperature goes up. The article points out that the RH tends to be adjusted during temperatures changes to be roughly constant which would suggest, to me, that the cloud amounts may well stay roughly constant. However, different types of cloud have different effects. Higher, thinner cloud tends to act like a greenhouse gas, while lower thicker clouds tend to reflect incoming radiation. This means that any changes in cloud type would also affect the whole. As the article suggests, the current effect is uncertain but considered (relatively) small - some studies show minor negative feddback and some show minor positive feedback. One climate researcher has said that this article: http://www.giss.nasa.gov/research/briefs/delgenio_03/ was a reasonable summary of recent thinking, though there is now a fair bit of work going into pinning it down.
Two interestingly associated effects are worth pointing. Firstly that deserts at night tend to be very cold due to the lack of water vapour in the air keeping their temperatures up. That they don't reach the Earth's black body temp. suggests either the radiative rate is not that high (calculable, but not by me) or that the "dry" atmosphere has greenhouse properties. Secondly the presence of clouds and/or moist air, at night, reduce the risk of frost.
(5) There are a number of varying uncertainties (there would have to be) and some processes are better understood than others. However, this article shows that several different approaches do keep coming up with similar climate sensitivities and resulting temperature ranges. It also shows that the potential 11C touted by some parts of the media showed a distinct misunderstanding of the paper that included it - which is not wholely unsurprising.
That's my reading of it - there may well be errors in my explanations/understanding, especially when it gets more technical.
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davidof, see "Our Last Century?" by Martin Rees. It's an interesting toe dip into end of the world scenarios.
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Some interesting points of view, which serve, as I originally asserted that no-one really knows what is happening or likely to happen. Most scientific sides to the arguement tend to ignore some data to conveniently make their point. When politics get involved and research is funded by organisations with a vested interest thus putting pressure on scientists and researchers to provide a more "biased" report, then clearly things become unclear!
Research funding into the environment should be blind. That is to say that the scientists should be free from any pressure to promote biased arguements etc.
What is acknowledged us that we are in the midst of a global warming trend that began in the middle of the 19th century which followed what is known as a "Little Ice Age" - a cold spell that lasted about 400 years. Nobody knows whether the present warming is due to a man-made or natural phenomenon. Atmospheric carbon dioxide is increasing. Man is the probable cause and we should act sensibly in aiming to reduce it. But creating fear and panic is not IMHO the way to ensure the "problem is dealt with". All sides in the arguement overstate their case and use selective analysis.
Pseudoscience is a dangerous and potentially disastrous state. If you don't believe that, look into Eugenics, a theory that gained significant support about a century ago.
Incidentally, to answer my own question on the number of glaciers in the world. There are 160,00. Mass data on them extending for 5 or more years relates to a mere 79. Not exactly a significant enough number to determine the state of the world's glaciers IMO.
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Lets also not forget the demographics associated with anthropogenic contributions to climate change.
The current world population is about 6 billion. This is projected to increase to about 9 billion in the next 50 years, at which it is projected to peak. Most of this increase will be in countries that have undergone relatively little industrial development, as yet. However, growth of population in these same countries is placing severe pressures on climatically important plant ecosystems (forests, that absorb significant quantities of carbon dioxide).
In the past, our already substantial industrial emissions have been generated principally by relatively small populations in the Northern hemisphere. We are now seeing the very much larger, and still growing populations in the Southern Hemisphere (and China) embarking on a substantial increase in their rates of economic and industrial growth. Whilst this will ultimately lead to a slowing in the rate of population growth (hence the projected peak at about 9 billion), this will also lead to increased demand for, and combustion of fossil fuels.
The consequences of this will need very careful management. (Understatement alert).
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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skanky, thanks for your detailed reply.
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