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What causes Global Warming?
What causes Global Warming?
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What causes Global Warming?
21/12/2014 10:30:01 »
Fred Loftin asked the Naked Scientists:
I listen to ABC from Toronto, Canada. Perhaps the
I listen to are old, perhaps they are current, I'm not sure.. But listening this morning to The Naked Scientist, as I sat in my study watching an early winter snowfall whistle by the door, prompted me to write to you. We are in Canada again this year experiencing weather that is about 8 ° cooler than in any average year. As I listened to the discussion of Climate Change on your program, I felt that you were studiously ignoring the 800 lb gorilla in the room. Your contributors discuss at length global warming as being caused by manmade CO2 emissions without paying any attention at all to other natural causes. It is very possible that Climate Change may very well be caused Solar activity. The sun can blow off in a couple of seconds more global warming at this tiny planet than can a thousand years of CO2 emissions. And while talking about CO2 emissions and what they are doing to our atmosphere consider this for a few moments that if we portray the Earth's atmosphere as a graph spread out like a football field 100 yards long here's what we see. The Earth's atmosphere is composed of the following molecules: nitrogen (78%), oxygen (21%), argon (1%), and then trace amounts of carbon dioxide, neon, helium, methane, krypton, hydrogen, nitrous oxide, xenon, ozone, iodine, carbon monoxide, and ammonia. Lower altitudes also have quantities of water vapor .So on our 100 yard football field from one end of the field up to a distance of 78 yards we have nitrogen. From that 78 yard line we have until the 91 yard line oxygen. From the 91 yard line we have one yard of argon. We then have water vapour which can in most parts of the world amount to 5% of the atmosphere. That brings us to somewhere past the 97 yard line. Then greenhouse gases such as carbon dioxide, methane, nitrous oxide et al, many of which are naturally produced add another yard or less. This doesn't add up to 100% or 100 yards because there are also some trace amounts of many chemical compounds in the air. But it seems to me that when we consider the total composition of the atmosphere the contribution of manmade gases add perhaps an inch or two on our 100 yards graph. Greenhouse gases comprise less than half of 1% of the atmosphere and most have been present at about this same level for millions of years notwithstanding the trepidation and hysteria of many environmentalists asserting that global warming is created only by manmade air pollution. I suggest that our tiny planet is really so big, that it has successfully withstood millions of years of volcanoes belching more greenhouse gas in a day than man could generate in a decade. This combined with solar activity and gigantic solar flares makes it reasonable to assume that most global warming if not all of it is natural. This thought and the observation that planet Earth seems to comfortably experience, about every 30,000 years, an ice ages followed by periods of extreme warming. Certainly we should endeavour to not pollute the planet. But on the other hand it appears unreasonable to blame global warming on manmade carbon emissions of the last century. Alternatively perhaps we should consider the impact of the unbridled growth of our human populations.
What do you think?
Last Edit: 21/12/2014 10:30:01 by _system
Neilep Level Member
life is too short to drink instant coffee
Re: What causes Global Warming?
Reply #1 on:
21/12/2014 13:55:44 »
Agreed. The idea that carbon dioxide controls global temperature is patent nonsense and not supported by any actual data.
1. The infrared absorption spectrum of CO2 is negligible in comparison with that of water.
2. Water not only absorbs infrared as vapour, but also reflects it as cloud, surface water, and surface ice.
3. The concentration and more importantly distribution of atmospheric water at all levels and in all states is hugely variable.
4. The latent heat of evaporation and melting of water accounts for almost all atmospheric activity.
5. The albedo of ice, the ability of the atmosphere to absorb more water as the temperature rises, and the shrouding effect of clouds on both solar input and radiative loss, are the dominant feedback mechanisms in all weather systems from daily spot weather to global longterm climate.
6. The only reliable longterm historic data we have, ice cores, shows that the CO2 concentration curve lags behind the temperature curve. If A follows B it cannot be the cause.
7. The famous short term "Mauna Loa data" admittedly shows a recent increase in CO2 and temperature, but the fine structure of the curve, with the underlying trend removed, shows that CO2 actually peaks in late summer, when anthropogenic emission is minimal: clearly the dominant emission is from insects and other coldblooded animals, whose metabolism is strongly dependent on temperature. Thus the longterm historic curve is consistent with a water cycle determining temperature, and the temperature cycle determining CO2 concentration.
8. We have no actual data on recent average global climate before 1970! Nobody had even visited the poles before the 20th century, and there is almost no useful data from the surface, never mind the depths, of the Pacific ocean, which covers 30% of the globe, or the Indian Ocean, which determines the climate of much of Asia. We have a little more data from the north Atlantic, but practically all the information of any useful degree of accuracy (and we are talking about year-to-year measurement repeatability of better than 0.05°C - serious meteorology, not tree growth rings) comes from grass airfields between 1910 and 1955, all of which were in any case close to civilisation. Until satellite data became available we knew almost nothing about the 70% of dry land that is not urbanised or the site of a major air war.
9. Beware of "adjusted" or "corrected" proxy data. It turns out that the annual adjustments are almost exactly the same as the purported effect they allegedly demonstrate!
10. The recent discovery of 500-year-old bryophytes under a retreating glacier clearly indicates that, at least in northern Canada, the climate was a lot warmer within recorded history - how else did they flourish? So any suggestion that the world is warmer now than at any time since Man evolved, is quite simply untrue.
11. And just to cap it all off, there does not seem to be an agreed definition of mean global temperature! If you haven't defined the parameter, how can you claim to have measured it, never mind identified the cause of its variation?
Last Edit: 21/12/2014 22:25:10 by alancalverd
helping to stem the tide of ignorance