[Douglas]

Since so many people here seem not to grasp the subject I'm going to explain it step by step.

First please note this is not global warming for dummies because we won't be going into the temperature record and any current temperature changes at all. We'll come back to why it isn't needed.

So lets start with the basic facts, the earth gets it's heat from the sun.

So first we need to establish exactly how much heat is directly from the sun. Well if we got rid of the atmosphere and just had pure solar heating this planet would be on average a rather chilld -18c, which is a bit below the rather warm 14c on average it currently sits at.

Why is it warmer than it should be? The greenhouse effect. It traps in heat that would have escaped like a big blanket keeping the planet nice and warm for well everything to exist. (how it actually works isn't important right now)

32 degrees is alot of heat really. From the 287k we sit at it accounts for 11% of the heat on this planet.

So what of Co2? Well it's one of those greenhouse gases and the one most commonly talked about because it is rising sharply due to humans (we'll talk about that later too).

Well the lowball estimate is that Co2 is responsible for 9% of the greenhouse effect (26% is the top end but we won't be doing the maths twice)

So if the greenhouse effect is responsible for 32 degrees of heat and 9% of that is down to Co2 that means the Co2 gives us a lovely 2.88 degrees of heat from Co2. Not a massive amount but significant.

The problem is this, Co2 is rising and rising quick. In 1832 it was at 284ppm and now it is at 385, a rise of 35%.

So a rise of 35% on 2.88 degrees is..... about a degree. And we are solely responsible for that.

How do we know we are responsible, well there is the simple logic that us pumping out loads of the stuff might increase how much there is. There is also evidence like the change in the radio isotope levels which make the obvious even more so.

So there we have it, a 35% raise in CO2 will result in at least a degree upward change in temperature.

Now if you want to question any of this do so, but do so on the topic presented.

[Parvus]

I have a question to which I know the answer but I will direct it to you instead of answering myself because I feel too lazy right now.

So you say the temperature rises by 1 degree. So what? Why is that so important, the temperature always changes and it's not just 1 degree. What is the result of this 1 degree change in temperature?

[Douglas]

Well because it ain't just going to be 1 degree for a start, that was a low-ball figure for what we have right now, it ain't going to stop today, CO2 levels are going to continue to rise and so it ain't going to be 1 degree.

As for what 1 degree will do, it will change our climate, accelerate the melting of the ice caps etc.

You can say "but the climate has changed for billions of years) and that is true, and with those changes we see extinction events, we don't like extinction events.

[Cabal]

Is global cooling not much more devastating a prospect than global warming? What historical extinction events can be attributed to global warming in comparison to global cooling (ice ages). Is global warming (and cooling) not inevitable anyhow, regardless of man's interference or lack there of? Aren't we admittedly in the last ~2,000 years of a 15-20,000 year warming interval before the climate returns to a cooling trend?

[Galoredk]

[youtube]DFbUVBYIPlI[/youtube]

Aren't we admittedly in the last ~2,000 years of a 15-20,000 year warming interval before the climate returns to a cooling trend?

No Cabal. You see even though the ice core data shows without a shred of doubt that it has been significantly warmer and colder before the world is still ending. That 0.7C over the last century is MAN MADE whether you like it or not!!

This is such a load of BS

[Zyx]

Is global cooling not much more devastating a prospect than global warming?

What is important is mechanism.

Global cooling can be a result of meteorite impact.

With regard mechanism, one ought to consider human prevention of global catastrophe.

The perspective that you take is defeatist.

Like observing an incoming meteor and shrugging one's shoulders claiming that meteorites have before hit the Earth.

To continue on global cooling, though, volcanic eruptions may play an role. Whereas we can not interfere with the devastation of volcanoes, to my knowledge, there's no reason to compare volcanic-induced cooling with man-induced warming. The "debate" revolves around taking responsibility and being cognizant of the destruction older generations can cause on younger ones.

[Kman]

Like observing an incoming meteor and shrugging one's shoulders claiming that meteorites have before hit the Earth.

Its not quite that simple because its pretty easy to prove that a massive meteor hitting earth would cause some major problems.
Global warming people on the other hand have to prove that burning a little oil will cause some catastrophic change in the atmosphere, despite of the fact that Co2 levels have been much higher during other periods of time in earths history.

They also have to prove that the Co2 will even have a noticable effect on the climate, which I doubt they can since nobody really understands how the climate works, scientists can even predict the temperature more than 3 days ahead of time, how on gods green earth do they know how the climate will be in 10-20 years then? It makes zero logical sense.

This Co2 scare is based on un-proven science and scare tactics, not any tangible evidence.

[Zyx]

despite of the fact that Co2 levels have been much higher during other periods of time in earths history.

The chemical composition through which humans may survive is very particular. Minor fluctuations would not make 'us' survive.

It's true that other animals live, but that's nothing to do with 'us.'

Further, I believe that it's the oxygen content that determines how long fires would blaze. This too is particular for fire usage.

It's not just "Let there be light" and everything comes together perfectly.

Humanity is incredibly particular.

It makes zero logical sense.

The greenhouse effect.

How else would you explain Venus' incredible temperature.

You know that it's surface is warmer than Mercury's, right?

As a matter of fact, Mercury can get colder than the Earth.

[ThereBeDragons]

This is an ice core temperature reconstruction.

As you can see, temperatures have undergone multi-degree fluctuations in the past, such as when temperature changed by about eight degrees about 240 thousand years ago, and it looks pretty frequent. However, if you'll zoom in, on, say, the period of rapid increase, and check the numbers, that eight degree increase happened over about seven thousand years. One pixel in that picture is over 800 years. No changes in the ice cores have registered changes in temperature as fast as (although it seems slow) as it has been doing over the past century or so.

And yes, way in the past, CO2 levels have been higher, say, about 2,000 ppm. At this time the West Coast of the US from California to Colorado was underwater. For the dinosaurs that were romping around then, this was no problem. Today, this would be a problem. So the fact that it's been warmer before is not a good reason why it should be okay for us to do it to the climate now.

They also have to prove that the Co2 will even have a noticable effect on the climate, which I doubt they can since nobody really understands how the climate works, scientists can even predict the temperature more than 3 days ahead of time, how on gods green earth do they know how the climate will be in 10-20 years then? It makes zero logical sense.

Weather is a chaotic system. Small fluctuations in initial conditions can cause great divergences in the models (it doesn't need to be as complex as weather; something as simple as a double pendulum exhibits chaotic behavior.) Consider, for example, the classical example of the chaotic system, the Lorenz attractor. A model attempting to predict precisely where you are after a few dozen loops is hopeless, but climate, the long-term average behavior of the weather, can be predicted (it looks like a butterfly.) So the fact that we do now know how it an individual trajectory behaves over some amount of time does not mean we cannot determine the overall structure.

As another, more weather/climate related example, on New Years Day, scientists would have a hard time telling you what the temperature would be on January 5, but they will have no problem telling you that it's going to have gotten a lot warmer by Independence Day.

[Cabal]

I wasn't really taking a perspective or position so much as I was simply raising some questions which sprang to mind. I'm still rather new to the 'climate change' debate, overall, though I don't have any issues with being more environmentally responsible--I do, however, have issues with that responsibility being mandated by the state, but that's another debate altogether.

Though, I will say the meteor analogy doesn't really seem to fit. A meteor on a collision course for earth could very well be inconsequential or completely devastating depending on the size and velocity, among other factors, I suppose. Regardless, what could I as an individual on earth do to prevent a meteor, of any substantial size and velocity, from hitting earth? It's not as if I could potentially change the course, size or velocity of the meteor in question by altering an otherwise insignificant habit of my daily life. I could, however, prepare for the impending devastation regardless of my inability to change anything about the meteor in question.

Mechanism aside, historically it seems that (inevitable) global cooling (and the subsequent ice ages) are much more hazardous to human life than global warming is, which was the inspiration behind some of my previous questioning. I reserve the right to be mistaken, of course.

So the fact that it's been warmer before is not a good reason why it should be okay for us to do it to the climate now.

But won't warming occur regardless of human contribution, or lack there of, even if human contribution is an indisputable fact? There seems to be a certain level of hubris which goes hand in hand with the idea that we (humans) can prevent a global phenomenon which has been occurring for thousands and thousands of years, if not much much more. So another question which comes to mind is why try to prevent something which, according to history, is going to happen no matter what we do?

[Kman]

Glaciers were covering most of Europe and North America 20.000 years ago, so the earth clearly must have been warming in order for these glaciers to go away, this proves that the earth warming phenomenon has been going on for a long time, long before humans started burning oil in their cars.

[Douglas]

Galoredk do you have some kinda of sight or mental issue? I'm asking because I thought I made it pretty damn clear that this thread was not about the temperature record.

That 0.7C over the last century is MAN MADE whether you like it or not!!

Again we are not discussing current global warming, it's raher rude and pissantish of you to come into a thread, not read it and insist on spamming it with off-topic material.

Global warming people on the other hand have to prove that burning a little oil will cause some catastrophic change in the atmosphere, despite of the fact that Co2 levels have been much higher during other periods of time in earths history.

Kman did you read the OP? If you want to correct it then do so.

Glaciers were covering most of Europe and North America 20.000 years ago, so the earth clearly must have been warming in order for these glaciers to go away, this proves that the earth warming phenomenon has been going on for a long time, long before humans started burning oil in their cars.

Do you know of the phrase pouring petrol on a fire?

[Galoredk]

Galoredk do you have some kinda of sight or mental issue? I'm asking because I thought I made it pretty damn clear that this thread was not about the temperature record.

This thread is about Co2s influence on temperature. It is therefore relevant to determine how much temperature does fluctuate on its own without human influence. If you do not include natural variation in your assesment on climate variability, then you miss a very large part of what drives temperature. Seeing as the temperature has been both significantly higher and lower in the past, one must ask the question, how you can be so certain as to eliminate natural variability as the cause.

One pixel in that picture is over 800 years. No changes in the ice cores have registered changes in temperature as fast as (although it seems slow) as it has been doing over the past century or so.

Did you even see the video I linked? It is evident from the ice cores that not only are scientists lying when they claim that the warming is unprecedented they are also lying when they the rate of change is unprecendented.

To suggest that you know whether or not we have seen a 0.7C increase over 100 years from ice core data is highly dubious if not misleading. The uncertainty down to a 100 year span is very high. If you insist you can look at the chart in my video and see if you can spot the numerous historical temperature changes that was at least as fast as the last 100 years.

These are NOAA ice core records:










I am sure you would like to focus only on this one:



So your argument that "No changes in the ice cores have registered changes in temperature as fast as (although it seems slow) as it has been doing over the past century or so." is ignorant at best and a blatant lie at worst. I do not want to be a judge of that.

[Douglas]

Galoredk could you please stay on topic. If you want to make a thread about the temperature record then you have that ability.

[Galoredk]

Galoredk could you please stay on topic. If you want to make a thread about the temperature record then you have that ability.

Your thread os on Co2s influence on global temperature. It is very important to perspectivize this onto temperature.

You wrote:

Why is it warmer than it should be? The greenhouse effect. It traps in heat that would have escaped like a big blanket keeping the planet nice and warm for well everything to exist.

Well the lowball estimate is that Co2 is responsible for 9% of the greenhouse effect.

The crude idea in the common popular presentation of the greenhouse effect is that the atmosphere is transparent to sunlight (apart from the very significant reflectivity of both clouds and the surface), which heats the Earth's surface. The surface offsets that heating by radiating in the infrared. The infrared radiation increases with increasing surface temperature, and the temperature adjusts until balance is achieved. If the atmosphere were also transparent to infrared radiation, the infrared radiation produced by an average surface temperature of minus eighteen degrees centigrade would balance the incoming solar radiation (less that amount reflected back to space by clouds). The atmosphere is not transparent in the infrared, however. So the Earth must heat up somewhat more to deliver the same flux of infrared radiation to space. That is what is called the greenhouse effect.

The fact that the Earth's average surface temperature is fifteen degrees centigrade rather than minus eighteen degrees centigrade is attributed to that effect. The main absorbers of infrared in the atmosphere are water vapor and clouds. Even if all other greenhouse gases (such as carbon dioxide and methane) were to disappear, we would still be left with over 98 percent of the current greenhouse effect. Nevertheless, it is presumed that increases in carbon dioxide and other minor greenhouse gases will lead to significant increases in temperature. As we have seen, carbon dioxide is increasing. So are other minor greenhouse gases. A widely held but questionable contention is that those increases will continue along the path they have followed for the past century.

The simple picture of the greenhouse mechanism is seriously oversimplified. Many of us were taught in elementary school that heat is transported by radiation, convection, and conduction. The above representation only refers to radiative transfer. As it turns out, if there were only radiative heat transfer, the greenhouse effect would warm the Earth to about seventy-seven degrees centigrade rather than to fifteen degrees centigrade. In fact, the greenhouse effect is only about 25 percent of what it would be in a pure radiative situation.
The reason for this is the presence of convection (heat transport by air motions), which bypasses much of the radiative absorption.

The surface of the Earth is cooled in large measure by air currents (in various forms including deep clouds) that carry heat upward and poleward. One consequence of this picture is that it is the greenhouse gases well above the Earth's surface that are of primary importance in determining the temperature of the Earth. That is especially important for water vapor, whose density decreases by about a factor of 1,000 between the surface and ten kilometers above the surface. Another consequence is that one cannot even calculate the temperature of the Earth without models that accurately reproduce the motions of the atmosphere. Indeed, present models have large errors here--on the order of 50 percent. Not surprisingly, those models are unable to calculate correctly either the present average temperature of the Earth or the temperature ranges from the equator to the poles. Rather, the models are adjusted or "tuned" to get those quantities approximately right.

I can only recommend you read "On the determination of climate feedbacks from ERBE data" by Lindzen and Choi who computed how satellite-measured net (solar + infrared) radiation in the tropics varied with surface temperature changes over the 15 year period of record of the Earth Radiation Budget Satellite (ERBS, 1985-1999).

The ERBS satellite carried the Earth Radiation Budget Experiment (ERBE) which provided our first decadal-time scale record of quasi-global changes in absorbed solar and emitted infrared energy. Such measurements are critical to our understanding of feedbacks in the climate system, and thus to any estimates of how the climate system responds to anthropogenic greenhouse gas emissions.

The authors showed that satellite-observed radiation loss by the Earth increased dramatically with warming, often in excess of 6 Watts per sq. meter per degree (6 W m-2 K-1). In stark contrast, all of the computerized climate models they examined did just the opposite, with the atmosphere trapping more radiation with warming rather than releasing more.

http://www.drroyspencer.com/Lindzen-and-Choi-GRL-2009.pdf

[Douglas]

Your thread os on Co2s influence on global temperature. It is very important to perspectivize this onto temperature.

No it isn't in fact this thread was created with the explicit reason so as not to be side-tracked onto climate records. I made that very clear from the start.

Deal with the topic at hand as presented or create your own.

[JohnRawls]

If that chart is right we should start burning oil ASAP . I mean soon the stick gonna decline we are gonna be screwed .

[Zyx]

It's not as if I could potentially change the course, size or velocity of the meteor in question by altering an otherwise insignificant habit of my daily life.

Our habits today are not as pollutant as the major corporations.

Someone yelling you down for leaving on your light ignores how we make tires in Liberia.

I am not telling you to turn off the A.C. insomuch as I am demanding Shell to do a CO2 cap.

You're making a strawman insisting that I insist that you change your habits.

Of course, it's good to change your habits no less.

Mechanism aside, historically it seems that (inevitable) global cooling (and the subsequent ice ages) are much more hazardous to human life than global warming is, which was the inspiration behind some of my previous questioning.

I do not know what you mean by more hazardous. You mean there was a larger population decline?

Tsunamis, floods and desertification are deeply effected by population increases. One global degree is more degrees at the equator.

So another question which comes to mind is why try to prevent something which, according to history, is going to happen no matter what we do?

Mechanism is important.

If Volcanoes are going to kill all of humanity, that doesn't mean that we should take a gun to every man, woman and child.

Glaciers were covering most of Europe and North America 20.000 years ago, so the earth clearly must have been warming in order for these glaciers to go away,

Again, volcanoes.

If a Volcano spews enough dust into the air, the global temperature will drop significantly as Sun light will rarer reach the surface. As this dust settles, the temperature will increase.

This isn't 'global warming' like CO2 and the greenhouse effect is.

[Galoredk]

Again, volcanoes.

If a Volcano spews enough dust into the air, the global temperature will drop significantly as Sun light will rarer reach the surface. As this dust settles, the temperature will increase.

This isn't 'global warming' like CO2 and the greenhouse effect is.

However convenient this explanation is, I am sure you can direct us to a study of sediments that show such massive volcanic activity for the given timeframe.
So lets start with 420.000 years ago, then 330.000 years ago, 250.000 and 170.000 years ago. If volcanic activity was responsible for a temperature dip of 8C, then surely this would show up in the sediments as a layer of ash.

A more plausable explanation would be Milankovitch cycles. But nevermind that. As long as the massive 0,7C we have experienced can be attribited to Co2, which of course requires a co2 sensitivity that is completely out of scope.

[Zyx]

Galoredk, a volcanic eruption need not distribute a large sample of sediments.

The Meteor from 65 million years ago did, but that's little to do with the Volcano.

Looking into Volcanic Eruptions, I found this.

http://www.sciencenews.org/view/generic/id/50189/title/Major_eruption_cooled_the_climate_but_went_unnoticed

Major eruption cooled the climate but went unnoticed
Ice-core records suggest that a major 1809 eruption cooled Earth even before the Tambora eruption and 'the year without a summer'
By Sid Perkins
Web edition : Monday, November 30th, 2009
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A large, previously unknown volcanic eruption somewhere in the tropics helped make the 1810s the coldest decade of the past 500 years, a new analysis suggests.

Scientists have long known about the 1815 eruption of Indonesia’s Mount Tambora, an eruption whose climate-cooling effect was so large that 1816 is often called “the year without a summer” (SN: 8/30/2008, p. 16). Now, evidence from ice cores taken from polar regions suggests that another major eruption occurred in a remote, unpopulated region of the tropics just a few years before Tambora blew its top, says Jihong Cole-Dai, an environmental chemist at South Dakota State University in Brookings.

Precipitation that fell on Greenland and Antarctica in 1810 and 1811 contained higher-than-normal amounts of sulfates, Cole-Dai and his colleagues report online and in the Nov. 28 Geophysical Research Letters. Some scientists had suggested that those sulfates came from small, local eruptions that happened to occur half a world apart but at the same time, he notes.

But new analyses of those sulfates reveal a shift in ratios of sulfur isotopes that indicate the sulfur had undergone chemical reactions high in the atmosphere. Those results show that the sulfates came from a single, massive eruption large enough to send aerosols into the stratosphere over both the Northern and Southern hemispheres, the researchers contend. That eruption, which probably occurred sometime around February 1809, was about half the size of Tambora and cooled the climate substantially, says Cole-Dai. “Then, before temperatures had a chance to fully recover, Tambora happened,” he adds.

Essentially, you are making unfounded demands on evidence, denying realistic and likely mechanisms without due cause.

I do not know what your "Hockey Stick" is, but maybe this Volcano contributes to it?

At least the thread now knows that Volcanoes happen.