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I have just found this one: The Royal SocietyWhich provides some food for thought and actually sets out some of the concequences of global warming (mankind induced or not) as the case may be. |
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quote: Originally posted by RogerBD: Originally posted by tarw quote: 2. We know that CO2 is emitted into the atmosphere by plants, volcanoes, bacteria and penguins breathing out. We know that CO2 is also absorbed by plants and the sea. Why should a relatively small increase in CO2 emission into the atmosphere kick off a dramatic climate change?
Good (if not the key) question in this whole debate! 
This link on the Royal Society page you linked to deals with this: quote: Carbon dioxide only makes up a small amount of the atmosphere, but even in tiny concentrations it has a large influence on our climate.
Before industrialization carbon dioxide made up about 0.03 per cent of the atmosphere or 280ppm (parts per million). Today, due to human influence it is about 380ppm.
CO2 levels are now higher than they have been in at least the last 650,000 years, and they're still rising, fast. NASA's James Hansen Says Atmospheric CO2 is Already Beyond Safe Limit |
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I'll say it again - do please read Mark Lynas's book "6 Degrees". I've just started chapter 3 (3 degrees), and he is discussing the dangers of making comparisons with past ages without taking account of the context. In the Pliocene era - 3 million years ago - the continental structure was pretty similar to now (the Andes and Himalayas had both formed by then), but there were plants growing in the middle of Antarctica and in northern Greenland because the global temperatures were about 3 degrees warmer than they are now. However, what is concerning is that CO 2 levels were very similar to the levels they have now reached (at nearly 400 ppm). Temperature tends to lag CO 2 by several centuries, so we will have to wait a while before the effects of our current levels take effect - but the fact that they have risen so much over the past few decades should be alarming. The problem is not that climate change is happening - as several forummers have pointed out, the climate has and it always will change - but it is the speed with which it is happening. For the most part, changes in the past have taken place over hundreds or thousands of years, allowing species to adapt to those changes. However, because of the speed things are moving at the moment, most species (particularly plants) are unable to adapt in the time scales involved, and are rapidly becoming extinct. I have no doubt that humans can and will adapt - but we forget that we also rely on plant and other animal life for our survival - even in this modern metropolitan age. If we lose some of our regular insect pollinators, we will also lose our crops, and be unable to feed our livestock. And if we lose our glaciers to warming, we will also lose the means to irrigate our crops in many regions of the world. Whatever side of the fence you are on, I expect that these events will become clear within the next 20 years. We are very fortunate to be living in the sort of countries that we do (assuming most of us are based in the UK). Our governments are likely to try to look after us. However, most people in the world will not have that luxury.
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quote: In the Pliocene era - 3 million years ago - the continental structure was pretty similar to now (the Andes and Himalayas had both formed by then), but there were plants growing in the middle of Antarctica and in northern Greenland because the global temperatures were about 3 degrees warmer than they are now. However, what is concerning is that CO2 levels were very similar to the levels they have now reached (at nearly 400 ppm).
Temperature tends to lag CO2 by several centuries, so we will have to wait a while before the effects
That's funny - i thought it was generally the other way round, CO2 lags temperature (the sea out gasses as it warms, and absorbs gas as it cools). Is there some scientific literature showing a historical example of CO2 leading temperature. Maybe Lynas has a reference in his book. |
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Probably in the past, yes, CO2 lags temperature because it is CO2 being released from warming oceans (which take 100s of years to warm because of huge size). However, we have been pumping huge amounts of CO2 into the atmosphere over the past 100 years. I don't think there is a temperature association to our production of CO2, but the temperatures will rise as a result of more of it being in the atmosphere. It works both ways!
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The point was more that the climate had stabilised at 3 degrees hotter with 400ppm CO2. The problem is that by the time we reach this "stable" temperature, the CO2 could well be double that, continuing to drive the process onwards and upwards.
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quote: The point was more that the climate had stabilised at 3 degrees hotter with 400ppm CO2.
The problem is that by the time we reach this "stable" temperature, the CO2 could well be double that, continuing to drive the process onwards and upwards.
So basically Lynas is assuming that the world was 3 deg hotter beacuse of the CO2 concentration being 400ppm, rather than the CO2 being 400ppm beacause the world was 3 deg hotter. He is then using this in his scary book to try and show what will happen today if CO2 reaches 400ppm (it will). No one really knows why the world was 3 deg hotter at that time. There are only theories (some cite different ocean currents to today), none of which can be proven. I bet alternative theories of why it was hotter are not discussed in the book. |
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Originally posted by Lucibee quote: For the most part, changes in the past have taken place over hundreds or thousands of years, allowing species to adapt to those changes.
Now here is one phenomenon that particularly interests me. My understanding is similar except that there have been periods of sudden (rather than gradual) warming or cooling during the history of this planet as Lucibee acknowledges. These more rapid events may coincide with extra terrestrial impacts or the eruption of super volcanoes; two potentially cataclysmic events which I have mentioned before which may be the simple explanation. But, does anyone have any idea how much CO2 (not to mention light obscuring particles in the upper atmosphere) that the eruption of a super volcano might produce? I well remember the sudden and significant drop in tempertaure during the solar eclipse in the UK a few years ago and the local impact of the eruption of Mount St Helen's in British Columbia in the late 80's (I lived a few hundred miles down wind of this volcano at the time ......... but we digress from the CO2 issue! |
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Super Volcanoes; Here it is kids - one to REALLY worry about! Super Volcanoes |
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quote: So basically Lynas is assuming that the world was 3 deg hotter beacuse of the CO2 concentration being 400ppm, rather than the CO2 being 400ppm beacause the world was 3 deg hotter.
No one really knows why the world was 3 deg hotter at that time. There are only theories (some cite different ocean currents to today), none of which can be proven.
I bet alternative theories of why it was hotter are not discussed in the book.
No - those are my deductions based on his descriptions. He was not assuming anything of the sort. But I am assuming that the climate was stable enough for plant life to have established at the poles. The climate is never just down to one or two factors - but CO2 is an important factor. As far as I know, the world was actually cooling at that time, as it was beginning to decend into the current ice age (of which we are in an interglacial). Do you have to prove how gravity works every time you get up in the morning (in case you hit the ceiling)? JUST READ THE BOOK!!!!!
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Originally posted by Lucibee quote: JUST READ THE BOOK!!!!!
I am not sure I want to spend my hard earned cash having just read the Customer Reviews on the Amazon Website - especially the two one stars reviews - one written by a Climatologist! |
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quote: Originally posted by legjoints: quote: Originally posted by Fizzatron:
No not really... it's far more likely that the government think that by creating a sense of worry about the environment, they can make a fast buck.
Which government are you talking about?
Primarily our annoying Labour one, as it's the one that most affects us.  |
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quote: I am not sure I want to spend my hard earned cash having just read the Customer Reviews on the Amazon Website - especially the two one stars reviews - one written by a Climatologist!
That's two out of twenty two. There were 13 with 5 stars. And what is your evidence that he is a climatologist? He says he works in climate physics - he might just make the tea...
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Original Post by Lucibee quote: That's two out of twenty two. There were 13 with 5 stars. And what is your evidence that he is a climatologist? He says he works in climate physics - he might just make the tea...
Fair comment - I thought you might check up on me there! But I doubt that he just makes the tea - where I work you have to do it for yourself! No, seriously I think he makes a point that is worth following up, which I will try yo do as there would appear to be some evidence that average global temperatures have dropped over the last 10 years - but I have yet to locate it. |
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For the benefit of others here is the subject comment from the Amazon Website:
Robert G Heath – reviewing Six Degrees by Mark Lynas
"Another silly book which overlooks the basic physics of climate change. How do I know? I work in climate physics. Climate forcing (temp change for doubling of CO2) is not a difficult concept, temperatures cannot go on rising just because of CO2 increasing. That's not how it works. You do not have to understand why, just remember that CO2 has been 15-20x more concentrated in the past and it was about same temp as now. It has been 3.5C warmer in the very recent past and CO2 levels were lower, as was SL. So where is the SL-temp-CO2 correlation? Also current rates of change of temperature are not out of the ordinary BY ANY MEANS. Sea level rises do not (within certain bounds)follow temperature changes up or down. A 6C temperature rise would take massive changes in solar output, which will happen, but not for a few billion years. Learn some physics. I ride a bike to work so don't care for 4x4's but they are not the cause of climate change."
We do not know what Robert's credentials are - but he makes some interesting observations that should fuel this debate!
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So lets get this straight. You are quite happy to take at face value the opinions of an unpublished reviewer on Amazon over and above all the climate scientists who have had their work published in Science and Nature? Ummmmm... He is clearly making the assumption that the life on earth does not affect climate, which is a pretty poor starting point given that we now know that it isn't true! Have you read any books on paleoclimatology recently?
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Just to 'balance' things up a little, here are the Amazon reviews for GGWS: 42 one star reviews
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quote: So lets get this straight. You are quite happy to take at face value the opinions of an unpublished reviewer on Amazon over and above all the climate scientists who have had their work published in Science and Nature? Ummmmm...
No Lucibee I am not - all I am saying is that he makes an interesting point that is worthy of further investigation - in the interests of a fair trial. |
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quote: He is clearly making the assumption that the life on earth does not affect climate, which is a pretty poor starting point given that we now know that it isn't true! Have you read any books on paleoclimatology recently?
To answer your question - No. But neither do I dispute the fact that life on earth has an impact upon the climate. What I do question is the contention that the burning of fossil fuels by mankinds is the SINGLE cause of global warming. |
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RogerBD
A good site for up to date info on temerature trends, weather events, bizzare GW stories and solar activity is the 'Wattsupwiththat' website by Anthony Watts (google it). If you have a look back through some of the recent entries you should find some posts and links on temperature trends.
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Thanks engineerer, I will take a look.
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quote: Another silly book which overlooks the basic physics of climate change. How do I know? I work in climate physics. Climate forcing (temp change for doubling of CO2) is not a difficult concept, temperatures cannot go on rising just because of CO2 increasing. That's not how it works. You do not have to understand why, just remember that CO2 has been 15-20x more concentrated in the past and it was about same temp as now. It has been 3.5C warmer in the very recent past and CO2 levels were lower, as was SL. So where is the SL-temp-CO2 correlation? Also current rates of change of temperature are not out of the ordinary BY ANY MEANS. Sea level rises do not (within certain bounds)follow temperature changes up or down. A 6C temperature rise would take massive changes in solar output, which will happen, but not for a few billion years. Learn some physics. I ride a bike to work so don't care for 4x4's but they are not the cause of climate change.
RG Heath is entitled to his opinion. He may work in climate science but I couldn't find any climate papers written by him. His review contains a number of strawman arguments, misconceptions and speculation. For example, CO2 levels were probably much much higher in the past, but the climate was much warmer at many of these times. In the very distant past 4-500 million years ago and longer, when CO2 levels were 15 times or more higher, he needs also to account for the fact that the sun was significantly less bright (10% or more). He also needs to account for the fact that our knowledge of the conditions on earth at this period is very sketchy. Current changes in temperature may or may not be "out of the ordinary". Again the evidence is sketchy. But he is speculating if he believes that such changes could take place without an identifiable forcing mechanism (such as solar changes, volcanic activity, albedo or greenhouse gas changes). As a physicist he should know that the energy must come from somewhere. And, minor point related to the above, the earth probably has *less* than a billion years before the sun is warm enough to initiate runaway greenhouse warming, as it is warming at about 1% per 100 million years IIRC. |
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