Looking at our wonderful lot of land here in Australia, what percentage of it would you say is er... concrete or bitumen or other such substances? 3%? maybe 4%... am i being too generous? we are, as a race confined to smallish dense patches along the coastline and most of the country west of the great divide (and east of perth and surrounds) is sparsely habited and would not factor into your concrete theory. the heat radiated by said structure would be localised and minimal in the big scheme of things i think.
I'll ignore Sonia as she hasnt offered any basis for her comments...
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Originally Posted by ving
not very polite.
No, in fact, very inpolite. But worse, hypocritical. He has offered plenty of comments of his own without offering any basis. Calm, rational & logical discussion and debate can quickly dissapate when people come pre-entrenched on one point of view. This applies to both sides.
My take :
It does seem a quite logical and likely outcome that, given our human numbers and technology and our inclination to [ab]use it, that we are going to have adverse effects on our environment. In fact, I would have thought it outright expected.
As time moves forward and our understanding of things increases, more and more members of the scientific community accept that GW is happening. All else being equal, I'd personally be inclined to listen to the vast majority of scientific opinion.
This graph below shows the record of global average temperatures as compiled by the Hadley Centre for Climate Prediction and Research of the UK Meteorological Office.
As you would expect, you can see normal variation and fluctuation in temperatures. However, it seems clear that we have moved from "normal variation" to a clear upward trend. 1 degree C sounds quite small, but on a global scale, 1 degree average is statistically incredibly significant.
The saddest part of all is that most models I've seen indicate that we've already passed the point where human activity is the only main driver of warming - feedback has begun. All data modelling is, of course, never going to be a 100% reliable method of prediction and understanding - but they are yet another tool for grappling with issues. I truely hope it's not the case.
very interesting Mr Thunder (if thats your real name! ). can you exlplain the rsudden rise from 1910(ish) to '45? if that is pollution induced that it sugests that we are polluting at the same rate as '75 on based on the rate of temp increase... which i doubt.
I saw sometime withing the last 6mths a similar graph that showed temperature fluxuations in the same way as this one but going back thousdands (maybe millions i cant remember) of years. it showed very much a wave formation.
heres one that measures icesheet temperature in antartica (votosk station) for the past 400,000 years. it clearly shows much fluxuation in temperatures. year 0 on the left i believe is now (or 2000 anyhow) and as you move left it goes back in time. As you can see we are currently on a rise in temperature ans still have a bit to go up in temperature to reach previous highs before we head on down again.... http://www.rideforclimate.com/climat...k-ice-core.gif
taken for 'ere http://www.rideforclimate.com/climate/climatepast.php
can you exlplain the rsudden rise from 1910(ish) to '45?
Hello Mr ving. I can not claim to be an expert (or even particularly knowledgable) in this field and so have no immediate answer - although I will look into it further when I have time (after Snake Valley this weekend! ).
I would note however that using 1910(ish) as the start of the upward trend is a *little* mischievious since that would be picking the very bottom trough of the local variation as the base point. It would have been no less valid to have picked 1930(ish) until 1940(ish) for instance.
While the graph can still have variation and anomaly, I personally find it interesting that the change toward upward trend more or less matches the time we humans developed the capability to really mess-up our enviroment (and did).
Quote:
Originally Posted by ving
heres one that measures icesheet temperature in antartica (votosk station) for the past 400,000 years. it clearly shows much fluxuation in temperatures.
taken for 'ere http://www.rideforclimate.com/climate/climatepast.php
Yes, there is a large variation of temperature over earth history - but those peaks and troughs take place over millenia, not decades. What we have now is significantly sharper within the context of the time period under scrutiny.
What I find even more interesting is how they obtained that data. That dat a was taken from polar ice samples. Those ice samples show not only changes to temperature, but also CO2 levels among other things. And the levels of green house gases present now completely blow out of the water anything we had in our entire past history.
Never presume that the presence of previous cycles and changes precludes us from inducing changes of our own. It's the first time in history we've been able to do so.
In fact, if you trace through the sources of the article you mention, you will find that the writers conclude with great concern over our current situation.
QUOTE: (major source from your article - http://news.bbc.co.uk/2/hi/science/nature/3792209.stm)
"There is great controversy as to whether human beings have changed the climate," said Professor McManus. "But there is no doubt about the fact that human beings have changed the Earth's atmosphere. The increased levels of greenhouse gases are geologically incredible." He added: "It is something of grave concern to someone like me, who sees the strong connection between greenhouse gases and climate in the past."
Hello Mr ving. I can not claim to be an expert (or even particularly knowledgable) in this field and so have no immediate answer - although I will look into it further when I have time (after Snake Valley this weekend! ).
now you are just making me jealous!
Quote:
Originally Posted by ThunderChild
Yes, there is a large variation of temperature over earth history - but those peaks and troughs take place over millenia, not decades. What we have now is significantly sharper within the context of the time period under scrutiny.
you make it sound like our last iceage was just last week . according to the graph i posted the past 2000 or so years have been on a plateau, proir to that there was a really steap climb and undoubtedly we are in for yet another increase for the peak to reach that of the previous peak. this peak will come at a fast rate just like the rest of the peaks over the last 400,000 year and we may or may not be contributing, but regardless of weather we contribute or not (and i dont think we make that much of a difference despite the CO2s being released) there is no stopping it cause its a natural cycle.
Quote:
What I find even more interesting is how they obtained that data. That dat a was taken from polar ice samples. Those ice samples show not only changes to temperature, but also CO2 levels among other things. And the levels of green house gases present now completely blow out of the water anything we had in our entire past history.
gee we know how to stuff up a planet dont we!
Quote:
Never presume that the presence of previous cycles and changes precludes us from inducing changes of our own. It's the first time in history we've been able to do so.
I believe once again that we are in the middle of a cycle and we may interfered with said cycle as shown in the plataeu that has occurred for the last 2000 years (per graph again). prior to the plateau there was a really fast rise, then it just stopped going up... did we cause that? it was within the last 2k years... I think its due for a fast rise again.
yeah we are stuffing up our very own air, but are we really causing climate change?
according to the graph i posted the past 2000 or so years have been on a plateau, proir to that there was a really steap climb...
That last "really steep climb" from my rough guestimation looks to be an approx 8 deg C change over 6500-7000 years. That is in the ballpark of 0.001 deg change per year.
What we have now appears orders of magnitude faster.
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yeah we are stuffing up our very own air, but are we really causing climate change?
Well, we know for sure that we're pumping scary amounts of greenhouse gases into the atmosphere - the likes of which has never occured in history. It's actually harder to imagine that we can continue to so with no effect. Especially since the rate at which we do so is increasing at scary levels - the amount of influence we humans exert is only going to increase dramatically.
Sure - there will still be natural variation, to which we add our own. Left to itself, perhaps the earth was/is going into an iceage in the future - but the thought of a possible 'iceage' thousands of years away seems somehow less pressing than a runaway greenhouse which will have direct impact within the lifetimes of our children.
At the end of day, anyone who right now says they know the answer with 100% surety is being quite brave. But on the balance of probabilties, I would say "yes - it is more likely that we are".
Thunderchild. Humans have had the ability to pollute the Earth for well over 600 years. I read somewhere once (sorry I didn't keep it) that sulphur pollution levels back in Roman times when they were making swords and nice chariots were on a par with current pollution levels, even more so.
This 'discussion' has got quite technical and very interesting. There seems to be one recurring them in all the arguments however. Humans=Bad
Looking at our wonderful lot of land here in Australia, what percentage of it would you say is er... concrete or bitumen or other such substances? 3%? maybe 4%... am i being too generous? we are, as a race confined to smallish dense patches along the coastline and most of the country west of the great divide (and east of perth and surrounds) is sparsely habited and would not factor into your concrete theory. the heat radiated by said structure would be localised and minimal in the big scheme of things i think.
G'day ving.
Your point/s are well taken and you hit on exactly the issue I was trying to put across (maybe I needed to be more specific, but at least it got you thinking and away from the computer for a while even if you weren't doing the work you are paid to do )
The issues I described do tend to be localize to a larger degree, though we are missing an aweful lot of trees all up the east coast of Australia and its these guys that help us the most (yes there is still alot of nice green grass between Bass Strait and Cape York. Unfortunately most of that used to be trees once upon a time. For helping climatealogical issues grass is as about as useful as the proverbial on a bull).
It's the microclimatealogical effects that can tend to be overlooked because of the amount of noise being made about worldwide issues. These incidental localized effects can have a far greater effect on the highest population density areas in a much shorter timeframe than the overall global effects. And they are exactly the ones that we are in a position to do more about. There is not much we can do to prevent the overuse of fossil fuels in developing countries, (and why should we, don't they deserve the same standard of living as we do?) but in the mean time we can do something to alleviate the effects on our own localized climate.
I spend a lot of time teaching, tutoring and working with conservation land management students and one of the most important things we try to instill into them is that trees are weather conditioners, ameliorants to the climate. Whatever the magnitude of the existing climatic conditions, large healthy forest soften the blow.
And this is something we can do now. Plant more trees. Help your local climatic conditions to stabilize and buffer possible future problems. Oh and of course they may even just help reduce some of that other stuff that's causing so much worry.
Fill a glass with ice, top up with water to the very rim and watch it melt, if any of you can make it overflow I will shut up, in fact, if you care to measure it you will find you have less water, it's simple chemistry that we all learned in grade 3.
They also must have told you in grade 3 that Antarctica is a continent and not an Icecube, try the experiment with the ice above the cup and see what happens. if you're gunna do science at least get it right...
Fill a glass with ice, top up with water to the very rim and watch it melt, if any of you can make it overflow I will shut up, in fact, if you care to measure it you will find you have less water, it's simple chemistry that we all learned in grade 3.
It follows from Archimedes' principle that when you melt ice floating in water, the water level will not change. But like Phil points out, the real problem here is that the polar icecaps are not floating in the oceans but sitting above it.
Boy has this thread got some legs !
I'm with Paul though ... plant more trees, if we all did just a bit our local areas would be a better place.
To quote an old green adage "think globally ... act locally"
Of course as astromomers, we need to make sure that they are low growing trees that dont obstruct our views of the night sky
How about redwood sized trees planted in concentric circles from the center of cities outward so that light pollution is blocked or kept reflected back into the city so we don't have to drive so far for dark skies Ian
They also must have told you in grade 3 that Antarctica is a continent and not an Icecube, try the experiment with the ice above the cup and see what happens. if you're gunna do science at least get it right...
Yep and if your going to quote me at least get it right, I said "floating ice" and specifically excluded land locked ice in my comment, besides, janoskiss, check your facts, the north polar cap is 100% floating, the south one is about 60% land mass. I did by the way quote a book for people to check facts, but of course you would have to go to the library for that and that means if it aint on the internet it cant be right, right? Stop postulating about the environment and think about what gains could be had and by who for this Green hoax, then you'll be heading in the right direction, you are all doing exactly what the Rothschilds and others want you to do. By the way Paul, a small correction on your comment about tree's, yes every tree is important and I for one cant get enough of them, but the greatest percentage of oxygen on the planet comes from the oceans and their life forms, the kelp forests of southern Tasmania for example produce more oxygen than the forests of Tasmania, we need to protect our oceans far more than our lands, but dont get me wrong, re-build the forests too.
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Another issue everyone has ignored is the ocean temperatures are rising due to greenhouse climate change .
Hell I was in Fiji recently and the sea was as warm as a bath
and we all know that warm water expands therefore higher sea levels
There seems to be some of these people here concerning climate change
Another issue everyone has ignored is the ocean temperatures are rising due to greenhouse climate change .
Hell I was in Fiji recently and the sea was as warm as a bath
Any change in ocean temperature so far would be well under 1 degree, and you certainly would not notice it by swimming in it. A few localised observations such as the experience you describe cannot be used to draw any sort of conclusions about the global climate. The water just happened to be warmer than usual when you were in Fiji that is all. (But the massive amounts of long term global climate data indeed strongly suggest global warming is under way and is going to continue.)
I'm curious nightshift, just what do the Rothchilds etc have to gain by this "Hoax" ?
I would have thought that the gain would have been to deny the problem so more coal & oil can be sold !
). can you exlplain the rsudden rise from 1910(ish) to '45? if that is pollution induced that it sugests that we are polluting at the same rate as '75 on based on the rate of temp increase... which i doubt. 
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Rising Sea Levels
