Quote :

So the "wobble" causes temperature increases that result in increased levels of C02 in the atmosphere ? What are the main explanations for that again? How does temperature increase lead to increased atmospheric C02?

Positive feedback loops. In completely natural cyclical climate change, the changes are driven by the various mechanisms in the Milankovitch cycle - that is, the initial temperature is forced by changes in obliquity/tilt/eccentricity. Those then feed into other changes which reduce the efficiency of the disposal part of the carbon cycle - ocean acidification and stagnation being the main one - which raises the levels of CO2, which in turn increases the temperature. Eventually the whole thing is reset by a reversal of the original forcing change.

None of those forcing changes currently apply.

Youngdan, global warming aside, do you admit that fossil fuel use will have to come down because the amount available will decrease??

Do you also admit that Western reliance on oil from unstable regions is a security risk??

If the answer is yes, (and I do not see how it could not be), then you too are supporting carbon emission reductions, REGARDLESS of what you think of global warming

ibis wrote:

Quote :

So the "wobble" causes temperature increases that result in increased levels of C02 in the atmosphere ? What are the main explanations for that again? How does temperature increase lead to increased atmospheric C02?

Positive feedback loops. In completely natural cyclical climate change, the changes are driven by the various mechanisms in the Milankovitch cycle - that is, the initial temperature is forced by changes in obliquity/tilt/eccentricity. Those then feed into other changes which reduce the efficiency of the disposal part of the carbon cycle - ocean acidification and stagnation being the main one - which raises the levels of CO2, which in turn increases the temperature. Eventually the whole thing is reset by a reversal of the original forcing change.

None of those forcing changes currently apply.

If this is too bothersome, point me at wikipedia or the IPCC, but what is the duration of a typical tilt ?



What are precession, obliquity (tilt?), eccentricity and solar forcing?

Found this good summary of the issues:

Quote :

As George Bush said at a recent press conference: "the globe is warming. The fundamental debate: Is it manmade or natural?"

Why does the scientific community think humans are significantly contributing to today's warming?

To understand why, first recognize that whenever the climate shifts, there's a reason for it. It does not wander around like a drunken sailor.

Based on decades of research, we can identify the factors that have influenced climate in the past:

Quote :

Tectonic activity: The arrangement of continents plays an important role in determining the climate, and if the continents move, the climate may very well change.
Orbital variations: The ice age cycles of the past few million years are driven by changes in the orbit of the earth about the sun. The earth's orbit has important variations, with time periods of approximately 25,000, 40,000, and 100,000 years.
Solar variations: The sun is the primary energy source for our climate. As the output of the sun changes, so does the climate.
Volcanoes: They inject ash and aerosols into the atmosphere, which reflect incoming sunlight. A strong eruption can cool the Earth for several years.
Internal variability: The climate system is complicated, and internal modes of variability exist. The most well known one is the El Nino/Southern Oscillation (ENSO). During the El Nino phase, the earth is much warmer than during the opposite phase, the La Nina.
Finally, there is a new player in the climate game: human-emitted greenhouse gases. These gases trap upwelling infrared radiation, thereby causing increases in the temperature of the surface.
If we look at the warming of the last few decades, we can immediately rule out tectonic activity and orbital variations -- they are much much too slow to account for warming over mere decades. We can rule out volcanic eruptions for a similar reason -- they affect the climate for only a few years. Thus, volcanic eruptions are also likely unrelated to the several-decades-long temperature increase we are experiencing.

We can rule out solar variability because we have high-accuracy measurements of the output of the sun from satellites since the mid-1970s, and we have not seen the increase in solar output necessary to explain the temperature increase. This is not to say that solar is playing no role, just that it cannot explain the majority of the observed warming.

Internal variability is the hardest to evaluate. We know that ENSO significantly changes the Earth's temperature, and so long-term ENSO-like variation is something we have to consider. However, nobody has yet put forth a viable mechanism or shown data that such a long-term cycle exists. In the absence of any evidence supporting it, we conclude that it's likely internal variability is playing a minor role in today's warming. Clearly, future research might cause us to re-examine this conclusion.

Finally, we have greenhouse gases. In this case, things work out well. Both the timing and magnitude of today's warming are well-explained by greenhouse gases.

This is why scientists conclude that humans are likely responsible for most of the warming of the last few decades. Greenhouse gases provide a reasonable explanation for the warming, while no other factor can explain the entire warming (though other factors, such as solar, might be playing a minor role). In the IPCC report, they attach the word "likely" to the statement about the importance of greenhouse gases, which denotes about 75% confidence that the statement is true. This takes into account our imperfect knowledge of the atmosphere, in particular with regard to internal variability, and that future work might lead to revisions of our views.

Finally, note that this conclusion does not come solely from GCMs. It sits on a firm foundation of peer-reviewed studies using a wide range of techniques. One of the things that gives us confidence is that the studies all paint a consistent picture of today's warming

. http://gristmill.grist.org/story/2006/11/20/21248/499

However the same poster says :

Quote :

And there are other problems -- e.g., we do not know with great confidence exactly what mechanism causes CO2 rise in response to the slight orbital-caused warming.

youngdan wrote:

You seem to have a problem understanding what I said. My first sentence is

"I consider the debate over" then I reference the poll showing most Americans then it is bunk. Do you understand what a poll is.

I do. I sometimes wonder if you understand what science is - or, rather, I occasionally give you the benefit of the doubt, since all the evidence is that you don't.

The most kindly construction I can put on your words is that you are literally saying that the debate - ie, the public discussion - over climate change has been settled in favour of denial.

In response I have to point out that the veracity of the science is, of course, entirely unaffected by public opinion. Since the science is correct, and the climate is changing, and we are changing it, then the debate is, of course, not closed - as they say, you can ignore reality, but you can't ignore the consequences of ignoring reality. The debate will therefore reopen whenever climate change is biting the doubters sufficiently hard in the ass. Until that time I wish you the comfort of your denial.

The debate is over here in the states and Canada anyway but Obama will try to push it through regardless. Now if it happens that the sea rises and the heat increases get back to us but until then we will freeze and bear it.

You ignore science that does not suit you. You ignore the fact that solar activity has returned to normal, you ignore the climate changes on the planets, you ignore that the ice cores show that the CO2 spike came after the warming but it still caused the warming.

That is why global warming is the new religon. You jesus freaks want all the doubting thomas's just to believe.

No thank you it is tea time so Mormans, Jehovah Wittness's, Hari Krishnas and Global Warmers can save themselves from getting frostbite

The way I think of it myself youngdan isn't in terms of global warming but of Gold backing for a currency. Gold backing limits quantity of money allowed to be printed but if there is a carbon cap then that also does the same thing. It depends on how equitable it might be though of course.

Do you see my point ? I'm not a big fan of global warming effects of CO2 but the financial effects of a carbon cap I equate with a gold standard because everyone and everything is comprised of and uses energy. Though I don't believe the climate change argument or am at least agnostic I think it's worth keeping an open mind and eye on it all the same.

I know a lot of your people are severely suspicious of a CO2 cap if that's what I understand the carbon plan is.... but I can't relate the effects of it as much to prevention of environmental destruction as to preservation of economic activity. The thing about Gore's film which stands out most for me is the fact that the Chinese have mpg and emissions standards that don't favour imports of American cars, so the Americans are losing out on a massive market. The Chinese are doing this for a reason: there's 4 or 5 times as many of them as there are Americans and they are using a fraction of the oil that Americans are so they are thinking of the future while many of your countrymen can't bear to think of using their own two feet to go a mile down the road.

There are limits to how much someone should consume I think and as long as the likes of energy is equitably distributed then it suits me. If you want to drive in a V8 and live in a house the size of three then you pay for it. I'm sure there are plenty of people who would be happy to pick up the slack and spend the dollars you offload on other things like education, travel, entertainment, art, music, animals and other interests.

On the Climate Change Science:
One thing though I'd like to know, if anyone knows it, is why we don't have more regular CO2 readings from the atmosphere when it's such a stroke-inducing problem or potential problem which hundreds of thousands of scientists have turned into insomniacs over ? Shouldn't we have daily readings ? Not that I'd specifically like to see what this massive global fall in output would do to the levels or because I am a half a trainspotting graph nut or anything ...

One last thing on Albert Bartlett, the fella who spoke about the diminishing resources of our planet and the horrible rapidity at which "tipping points" arrive:
He bases his argument largely on one image - the exponential increase of bacteria in a bottle. This bacteria doubles in number every minute. He poses his question: In one hour, a bottle with only one bacteria at the beginning is full at the end of the hour - say between 11 o'clock and 12 midday. When, he asks, is the bottle HALF FULL ?

I'd like to know if such a bacteria really exists or is it simply an analogy ?

youngdan wrote:

The debate is over here in the states and Canada anyway but Obama will try to push it through regardless. Now if it happens that the sea rises and the heat increases get back to us but until then we will freeze and bear it.

You ignore science that does not suit you. You ignore the fact that solar activity has returned to normal, you ignore the climate changes on the planets, you ignore that the ice cores show that the CO2 spike came after the warming but it still caused the warming.

1. solar activity has returned to normal? In what sense, and from what? Solar output has not increased since the 1970's, and the solar contribution to current climate change has been extensively modelled - it is not responsible for the current changes.

2. climate changes on the planets? All the observations we have are of regional ice melting at the Martian South Pole over 3 years. If that's evidence of climate change, what the heck is the Arctic melting?

3. what's in the ice cores is natural climate change, where the initial forcing is done by cyclical physical factors, and the CO2 increase is a result of that, and the contributes to further temperature rises. What's happening now is not natural climate change (it's hundreds of times faster) - it's being driven by excess CO2. In both cases the CO2 acts as a greenhouse gas, which is a well-studied and inarguable physical effect.

youngdan wrote:

That is why global warming is the new religon. You jesus freaks want all the doubting thomas's just to believe.

No thank you it is tea time so Mormans, Jehovah Wittness's, Hari Krishnas and Global Warmers can save themselves from getting frostbite

I couldn't give a flying fuck whether you personally "believe", as long as there is the necessary political will to act. As long as your personal pig-headedness doesn't prevent your government from doing something to help prevent/mitigate climate change, you're more than welcome to wallow in your own self-satisfied stupidity.

The majority don't believe. that is what you don't seem to understand. That is why ye are Jesus freaks

youngdan wrote:

The majority don't believe. that is what you don't seem to understand. That is why ye are Jesus freaks

The majority used to believe the earth was flat. On the other hand there is definitely a touch of religion about some people's climate change belief though. What percentage of the people who believe it is happening understand what it is?

Right on Cactus and when people said the world was round the Jesus Freaks burned them at the stake. Ibis and Co will believe nothing except their Gospel. In 10 years time when it is freezing they will still be talking about the Earth wobbling.

I wish someone could explain to me how paying for energy surveys for dwellings as a condition of sale does anything at all to reducing CO2 omissions or even assist in reducing heating costs.

Person wishes to sell a house, solicitor advises one is needed, money is paid, a bright young thing with a dubious qualification gets in car and goes forth to do a survey and gets it typed up, contract's are signed and the report is binned.

Strikes me as stupid.

youngdan wrote:

The majority don't believe. that is what you don't seem to understand. That is why ye are Jesus freaks

(Angus Reid Global Scan) - Many American adults support the principles of creationism, according to a poll by CBS News. 53 per cent of respondents believe God created human beings in their present form.

Conversely, 23 per cent of respondents believe human beings evolved from less advanced life forms over millions of years, but God guided this process, while 17 per cent think God had no part in the evolution of man.

The wisdom of the US public!

While we're on polls, though - this is the September 2007 BBC worldwide survey (22,000 adults in 21 countries) here.

I do hope you remembered to put your head up your arse before you put it in the sand. The other way round...not so nice.

"The other way round...not so nice"

Thanks for the warning Ibis. As long as you got the hang of it eventually

youngdan wrote:

"The other way round...not so nice"

Thanks for the warning Ibis. As long as you got the hang of it eventually

So are you going to base your view on the Rasmussen Poll youngdan? I doubt the majority want Ron Paul for President, so I suspect that you do have other ways of coming to conclusions than following the pack?

Well the pack thinks it is a load of rubbish and they have had a bellyfull of the global warming jesus freaks. It is time for them to move on and get over it.

Well, in the absence of overwhelming proof to the contrary, its back to the flat earth theory then.

Exactly Cactus. People are tired of the global warming jesus freaks insisting the Earth is flat. Even after people sailed round the world the Church insisted it was flat. That is why it is the new religon. It dosn't matter if it is -50 their faith tells them the Earth is warming.

God help them.

youngdan wrote:

Right on Cactus and when people said the world was round the Jesus Freaks burned them at the stake. Ibis and Co will believe nothing except their Gospel. In 10 years time when it is freezing they will still be talking about the Earth wobbling.

If I'm understanding rightly, the idea is that the wobble affects temperature, and when the temperature goes up, the quantity of snow and ice reduces, there is less reflection of the sun: a warming spiral is set off. Why has the temperature on each previous occasion reached a peak and then dropped again, I'd like to know. Hopefully, Pax, Ibis or some other well informed person will come and tell me.

Also Ibis has said that this spike is much faster that previous (pre human) ones. I haven't yet been able to find any information about that.

These people agree with you, youngdan. http://news.bbc.co.uk/2/hi/science/nature/1131275.stm

And these: http://news.bbc.co.uk/2/hi/in_depth/sci_tech/2000/climate_change/1026375.stm

Sir John Houghton is quoted as saying that it is the fastest warming for 10,000 years, but tbh, in climate terms, 10,000 years is the day before yesterday.

That is an excellent article about the Sun Cactus. I sometimes wonder whether Ibis has any understanding of science at all but I give him the benefit of doubt. Yesterday he was asking where did I see evidence of solar activity having returned to normal. Everyone knows the activity has died off and now the warmers are in a panic.

They will say that Professor Stott and the others in the first article don't have degrees or something else. Everybody is wrong but the jesus freaks who believe.

Do you remember the "millenium bug?"

I remain open to being convinced that humans are causing global warming, but at the moment am struggling to find a reasonable degree of proof.

I would be more concerned at the moment about water and top soil depletion.

Yes Cactus. Along with fossil fuel depletion and general pollution...oh, and we've all forgotten overfishing.

Governments have focussed on global warming to achieve geologically mandatory, looming cuts in energy supply and it has been a HUGE PR mistake; most people are unwilling to make voluntary cuts when their jobs and standards of living are threatened. So we'll just have to be pinned in a corner by insufficient supply.

and we think the economy is in the doghouse now. This is the tremor before the earthquake, as Eddie Hobbs helpfully pointed out. Just wait till the oil supply dives by 1/4 overnight and the world's governments have spent all their moolah on the banks internal black holes

In comparison with these issues, climate change is an irrelevance. Geology will force Co2 cuts. End of story

Lets look on the bright side: the crash will make a big hole in gas and oil consumption

cactus flower wrote:

Lets look on the bright side: the crash will make a big hole in gas and oil consumption

Indeedy.....the thought had occurred. But I am also wondering how much of the "voluntary" cuts Opec is making are actually all that voluntary. I guess we will only find out if and when the price goes up again, as to whether they CAN actually ramp up production or not.

Sigh. Look, there isn't a simple proof involved here. There are multiple possible sources of climatic change within a very complex system - so there isn't a simple way of drawing a line from A to B and going QED.

What there is instead is modelling. In other words, all the possible sources of climatic change are measured, and their effects on climate are then modelled in computer simulations.

Anthropogenic carbon emissions get a look in to the models because of a very simple physical characteristic of CO2, which is that it absorbs the longwave radiation emitted by the earth. That longwave radiation is how the earth re-emits the solar radiation it receives, and thus maintains a steady temperature. The more CO2 there is in the atmosphere, the more of that re-emitted longwave radiation is captured by and heats the atmosphere - as opposed to being radiated off into space.

So if we are increasing the amount of CO2 in the atmosphere, it stands to reason that there is a probability that we are causing some degree of warming.

The amount of warming/cooling caused by each of the different sources of climatic change, including anthropogenic CO2, is predicted by the various computer models that simulate climate. When all factors are taken into consideration, the best match for the observed trend in global temperatures is the observed trend in global greenhouse gases, and the best match for that trend is the trend in anthropogenic emissions.

All of this gives us a probability that the cause of the currently observed climate changes is anthropogenic emissions. Between the increasing sophistication of climate models, the increasing computer power available to run them, and the increasing range of such models, that probability has risen to 95% plus. It is not, and never will be, a certainty.

The 'consensus' so frequently spoken of in respect of climate change is, first and foremost, a consensus of models. Hundreds of institutions worldwide run climate models, all with different starting assumptions - but all of them tend to converge on the same "most likely suspect" for current climate changes - atmospheric temperature forcing by anthropogenic airborne greenhouse gas emissions.

Yes, the "minority report" is always there, and always has a chance of being the right answer. All we can say is that it's a small chance as far as current science can tell - and that's based on thousands of 'second opinions'. I shall be absolutely sodding delighted if it turns out to be correct, because it means there won't be huge catastrophic changes to the planet's ecology, but I'm no more going to put my faith in it than I would a 3% chance that my cough wasn't cancer.

Policy-wise, the predicted downside effects of rapid climate change are so large that even though we're only 95%+ certain our emissions are the culprit, not doing something about that would be reckless beyond belief - putting the current financial crisis into the farthing place.

In the meantime, those with vested interests, and those who emotionally reject the idea (and who rejected the tobacco-cancer link, the asbestos-cancer link, the sulphide-acid rain link etc etc), will continue to harp on the existence of the minority report without any consideration of its probability. The mere existence of alternative possibilities should not preclude action on the basis of risk analysis - and the risk analysis says it's probably us, the consequences probably catastrophic, and the time for action now.

People like to remember the millenium bug as soemthing that didn't happen. They forget that a large part of the reason it didn't happen was because millions of programmer hours were put into fixing it in advance.

Were you able to find a graph that would show that warming is faster than it was in the previous spikes Ibis?

I''ll have a look at the C02 absorbtion of longwave radiation later, thanks for that.