BBC: Globe Not Warming, Maybe Cooling

[Engulf]

are you talking about this, or did you not know what the Vostok correlation is?

here a zoom of the last 2000 years:

It looks like you love graphs, which is good I guess since it's easy to refer and understand am I right? Not so fast there. Let me give you a short explanation about the Vostok correlation and the questions surrounding Hansen's claim that it is proof that temperature and CO2 correlates perfectly, or close to.

Hansen's theory claims that CO2 was indeed the forcing mechanism behind the push in temperature based from the Milankovitch cycle in the Earth-Sun geometry, which causes a small temperature change, which then led to a CO2 change before CO2 taking over as the forcing mechanism. However, it is well known that the Vostok CO2 record lags the temperature record by an average of 800 years, which was a problem since from the graph itself, why do the CO2 changes tend to come after the temperature changes? Moreover there's also the question about how far or how quickly the CO2 migrates through the ice core, so we do have an uncertainty here.

However even if the CO2 and temperature record line up nicely, we're only assuming that there was no forcing besides CO2 that caused the temperature changes. Hansen's theory still needed another initial forcing that was responsible for the initial temperature change which started the entire CO2/temperature cycle we've seen in the Vostok record. Question here is: what if that forcing was a key influential factor in the increase and decrease in the temperature record? If that is so, then the co-variations between temperature and CO2 becomes less.

But if we still would like to rely on Hansen's claims, and CO2 is the main forcing in the Vostok record, then it would only take about a 10ppm increase in CO2 to yield an increase in temperature by 1'C. The full range of CO2 forcing in the record amounts to 1.6 to 2 Watts per sq. meter, and if that caused the full range of temperature variations, then we'd probably have about 10'C of warming from the CO2 we've pumped into the atmosphere from fossil fuel burning right now. (source: Ice Ages or 20th Century Warming, It All Comes Down to Causation; Roy W. Spencer, Ph. D)

And about the second graph you supplied, that's the 2000 year temperature comparison reconstructed from Michael Mann's hockey stick graph. I have a big problem with that graph since it's already been proven by Dr. McIntyre and backed by the Wegman committee that it was modelled out of an error in statistical methodology. So hmm...not much to talk about there. :-/

Edited October 13, 2009 by Engulf

[Engulf]

Quick question: why do you refuse to accept global warming? Refusing to accept responsibility for it until you have absolute, undeniable proof slapped in front of your face?

We do not refuse to accept global warming, in fact our planet has warmed up before multiple times ago. The question is: are we directly responsible for it? If so, where is the ultimate evidence that shows it? Up till now, we have tonnes of questions and hypotheses, but none have been close in zipping the debate up. And we are scientists, so we are built to find absolute, undeniable proof slapped in front of our faces in order for us to accept a hypothesis or claim as truth. If that disturbs you, go read a story book instead. That'll take the burden off a bit...=P

[Caesar]

We do not refuse to accept global warming, in fact our planet has warmed up before multiple times ago. The question is: are we directly responsible for it? If so, where is the ultimate evidence that shows it? Up till now, we have tonnes of questions and hypotheses, but none have been close in zipping the debate up. And we are scientists, so we are built to find absolute, undeniable proof slapped in front of our faces in order for us to accept a hypothesis or claim as truth. If that disturbs you, go read a story book instead. That'll take the burden off a bit...=P

I agree, I think the planet has been getting warmer since it was created. I just don't see any proof that man is causing it or that cap and trade would some how help stop that process.

[Startraveler]

However, it is well known that the Vostok CO2 record lags the temperature record by an average of 800 years, which was a problem since from the graph itself, why do the CO2 changes tend to come after the temperature changes?

CO₂ changes don't come after the temperature changes, they come during the temperature changes (800 years into a ~5,000 year-long warming period doesn't qualify as after). That merely indicates that CO₂ forcings have historically been feedbacks and not the initial forcing. Orbital forcings are generally thought to kick things off with CO₂ feedbacks playing a key role. That doesn't necessarily reflect on the present situation; the IPCC's Fourth Assessment estimates the anthropogenic forcings relative to solar forcings over the past few centuries:

There is very high confidence that the global average net effect of human activities since 1750 has been one of warming, with a radiative forcing of +1.6 [+0.6 to +2.4] W/m

²

(Figure 2.4). {WGI 2.3, 6.5, 2.9, SPM}

The combined radiative forcing due to increases in CO

₂

, CH

₄

and N2

_O

is +2.3 [+2.1 to +2.5] W/m

²

, and its rate of increase during the industrial era is very likely to have been unprecedented in more than 10,000 years (Figures 2.3 and 2.4). The CO

₂

radiative forcing increased by 20% from 1995 to 2005, the largest change for any decade in at least the last 200 years. {WGI 2.3, 6.4, SPM}

Anthropogenic contributions to aerosols (primarily sulphate, organic carbon, black carbon, nitrate and dust) together produce a cooling effect, with a total direct radiative forcing of -0.5 [-0.9 to-0.1] W/m

²

and an indirect cloud albedo forcing of -0.7 [-1.8 to -0.3] W/m

²

. Aerosols also influence precipitation. {WGI 2.4, 2.9, 7.5,SPM}

In comparison, changes in solar irradiance since 1750 are estimated to have caused a small radiative forcing of +0.12 [+0.06 to +0.30] W/m

²

, which is less than half the estimate given in the TAR. {WGI 2.7, SPM}

But if we still would like to rely on Hansen's claims, and CO2 is the main forcing in the Vostok record, then it would only take about a 10ppm increase in CO2 to yield an increase in temperature by 1'C. The full range of CO2 forcing in the record amounts to 1.6 to 2 Watts per sq. meter, and if that caused the full range of temperature variations, then we'd probably have about 10'C of warming from the CO2 we've pumped into the atmosphere from fossil fuel burning right now.

How does this suggestion make sense? Temperature change isn't linearly related to CO₂ change, it's linearly related to forcing. And forcing is logarithmically related to CO₂ levels (or, rather, the ratio of final to initial concentrations or perhaps some slightly more complicated relation). The fact that this is sensitive to initial CO₂ concentrations would seem to make a statement like "it would only take about a 10ppm increase in CO2 to yield an increase in temperature by 1'C" nonsensical as some kind of general rule. The chance in forcing in going from a CO₂ concentration of 200 ppm to a concentration of 210 ppm is different than the forcing in going from our current 387 ppm to 397 ppm.

[SilverCougar]

Not really, we just had the coolest summer I can remember. We hit 90 like 3 times the whole damn summer. We are well below temp average and have been for awhile.

And yet here in western WA we had temps soaring to 110. Not something common here. Normaly our temps stay 70's to 90's.

Though I would rather turn to the science then close my eyes and ignore that yes, the climate is changeing as it always does. And yes humans do have a hand in it's severity.

[danielost]

graphs again, Do not want to see more graphs, they are getting boring , Show us the proof global warming is down to man. show it, debate over.

i have been asking for that for a long time. don't expect to see it. just more graphs. oh and his graph didn't agree with what he was saying. if you noticed the temp line it was going down when the co2 lvls line was rising in the past 9 years.

[Mattshark]

by those same 'scientific standards' are you not required to have all the necessary information before coming to an educated conclusion?

we don't have the knowledge or the data to do so. that's only going by your usual scientific standards though.

Yes we do actually. We have lots and their are a lot of papers showing this and we are seeing the predicted effects already.

[Mattshark]

Where is the freedom...? where is the referendom or debate..?

freedom to choose...?

Science is not a democracy, nor should it be.

Wrong, back in the 1970s, TIME magazine among many news sources ran an article about the coming Ice Age. We had a ton of atmospheric scientists supporting the claim too as the United States came to grips with some of the lowest mean temperatures ever recorded, shortest summer lengths and prolonged winter periods with blistering colds and record low temperatures. I personally back this one up myself as I had to reconstruct the climate data for a number of cities during that period and in short, it was ridiculously low and filled with blue colors.

So we had science too to back global cooling back then, but...well, like I've said, how much can we count on to dish forward a global cooling reality? If we're looking at about 20-30 year period from 1960-1990, which is roughly the same way we're viewing global warming right now, then we do have global cooling. However, once we expand our scopes to a more larger, fairer frame (which is why we have climatology), then we'll see an oscillation instead. We must understand that global cooling and global warming are both real (we've seen, known, recorded them down), but are we responsible for that? If so, how? And that "how" alone has many, many ways of explaining it...we just have to be careful about which ones are right or wrong.

Time is not a scientific publication. The global cooling thing was a production of the media and was never accepted in science. From 1960 to 1990 there is very much a warming trend, In fact if you look over the last 100 years you see a clear warming tend. We do not see an oscillation at all, sorry but that is absolute rubbish.

[Mattshark]

I agree, I think the planet has been getting warmer since it was created. I just don't see any proof that man is causing it or that cap and trade would some how help stop that process.

You can think that all you like, you are however completely 100% wrong. The planet has previously been considerably hotter than it is now. In fact it was molten when it first formed so it was much much hotter. During the Permian for example a lot of the planet was desert and they had a sharp 10°c rise in temperature due to a supervolcano and releasing methane pockets making it hotter again (this caused the worlds largest mass extinction. During the age of the dinosaurs the tropics where much wider and Antarctica was inhabitable.

So that just doesn't stand up to reality.

Did anyone actually bother to read any of the papers I put up in the other threads?

Edited October 13, 2009 by Mattshark

[Mattshark]

We do not refuse to accept global warming, in fact our planet has warmed up before multiple times ago. The question is: are we directly responsible for it? If so, where is the ultimate evidence that shows it? Up till now, we have tonnes of questions and hypotheses, but none have been close in zipping the debate up. And we are scientists, so we are built to find absolute, undeniable proof slapped in front of our faces in order for us to accept a hypothesis or claim as truth. If that disturbs you, go read a story book instead. That'll take the burden off a bit...=P

It is not a hypothesis, it is a theory, there is a difference you know. Since you cannot distinguish between what is media reports and scientifically reported data (or know that the world was heating up between 1960-1990) then I presume you have not actually read to many papers on the subject. There are over 35 years worth.

[Rob Awesome]

I guess it is time I 'fessed up. The global warming over the past 25 years is a direct result of my holding the door open in winter time. Mom would shout "close that door we're not trying to heat up all outdoors!"

I wouldn't listen, as the years past it got worse, from holding the door open to get my toboggan in and out to waiting for five minutes to see if the dog really wanted to go out to carrying snow shovels and salt in and out while clearing the driveway.

Starting this year I plan to remedy the situation by hibernating.

Problem solved.

[questionmark]

In related news:

Climate change may be faster than expected

OAK RIDGE, Tenn., Oct. 13 (UPI) -- A team of U.S. scientists has, for the first time, successfully incorporated the nitrogen cycle into global climate change simulations.

The experiment's findings at the Oak Ridge National Laboratory and the National Center for Atmospheric Research bring into question previous assumptions regarding carbon feedback.

Read more ...

Sounds a little different than the erudite opinion of Don Easterbrook ...

[Queen in the North]

We do not refuse to accept global warming, in fact our planet has warmed up before multiple times ago. The question is: are we directly responsible for it? If so, where is the ultimate evidence that shows it? Up till now, we have tonnes of questions and hypotheses, but none have been close in zipping the debate up. And we are scientists, so we are built to find absolute, undeniable proof slapped in front of our faces in order for us to accept a hypothesis or claim as truth. If that disturbs you, go read a story book instead. That'll take the burden off a bit...=P

Merely asking, and I wasn't asking you, so there's no need for that.

[Caesar]

You can think that all you like, you are however completely 100% wrong. The planet has previously been considerably hotter than it is now. In fact it was molten when it first formed so it was much much hotter. During the Permian for example a lot of the planet was desert and they had a sharp 10°c rise in temperature due to a supervolcano and releasing methane pockets making it hotter again (this caused the worlds largest mass extinction. During the age of the dinosaurs the tropics where much wider and Antarctica was inhabitable.

So that just doesn't stand up to reality.

Did anyone actually bother to read any of the papers I put up in the other threads?

No kidding, I wasn't going back to the creation of this planet, I'm sure the planet had its hot and cold periods from supervolcano, meteors, asteroids, comets ect. but the overall trend has been warmer over time.

Now you can take those papers and whipe your you know what off with them.