Anthropogenic Climate Change: It's for real.

Greg - A lot (maybe most) of the smart people I know who have been called "climate change deniers" (or worse) actually do believe that human activity is a major cause of observed warming in recent decades. But they doubt that CO2 is the main driver. I might not be as smart as some of them, but I do share their skepticism about the role CO2 is playing in all this.

Bob
Which part of "stratospheric cooling"
do you not understand?

http://tinyurl.com/2eafon6

http://answers.yahoo.com/question/index?qid=20071106215441AAPEhMj

I've noticed that a lot of smart people who nonetheless "did not accept" ... have stoped talking about it

I can relate to that. (Though not the stoping part. Don't know what excavation has to do with this). I think it might be a kind of bizarre manifestation of open mindedness. One's willing to listen to the other side and the climate "skeptics" do give arguments that are superficially compelling. Enough so that their productions compare to that Al Gore's Oscar. If one is not really inclined to get to the bottom of things, an intelligent person might be fooled into thinking that there is some merit to the "skeptics'" nonsense.

BTW, Bob Koepp's "AGW, but not CO2" 'theory' is a new one to me. What's that all about?

That's because it's been a hot summer. Don't worry, in winter they'll be back, asking how there can be global warming if it's so damn cold outside.

No Bob. It is not 'skepticism' to doubt the role of CO2 in climate change - it is flat earth denialism.

The role that atmospheric CO2 plays in warming the Earth has been known for over a century. What part of this well established scientific principle are you 'skeptical' about, and on what basis?

You have no need to answer, because I know you can't. You, and others of your ilk, are not skeptics at all - you are denialists with a worldview based entirely on politics and a complete lack of understanding of how science works. Maybe if you read a few science papers rather than listening to the views of ill-informed bloggers (I am not talking about Greg here by the way), right-wing politicians and shock jocks, fossil fuel industry lobbyists and the idiots on Faux News you might be able to form an informed opinion on the matter.

Greg, the course of this was predicted a long time ago:

* It's not really getting warmer.
* It may be getting warmer, but it's not caused by humans
* It may be getting warmer because of humans, but that's a good thing
* It may be that humans cause undesirable warming, but there's nothing we can do about it
* We could do something about the undesirable warming we're causing, but it's politically/economically impossible
* Look at these pictures of my new beach house in the Aleutians!

I saw a sun spot today - that must be why it's such a hot summer!

As a scientist my attitude is that people are too damned stupid to do anything about it (and the pro-AGW scaremongers out there - invariably modelers it seems - don't help any) so I'd like to see more instrumentation out there to take measurements over the next 50 years so we can get a better understanding of things and come up with better constraints on just how much warming we can expect, etc. My expectations are very low, and the reason is my familiarity with the mineral extraction industry. Everyone wants their base materials cheap as can be and there are many operators around the world. The vast majority of mining operations really screw up the area and absolutely no one wants to pay to reduce the harm or to clean up afterwards. Outlawing the use of rivers as dumping grounds in the mercury + cyanide process for gold extraction as practiced 100 years ago is one of the notable and rare exceptions. The only differences with atmospheric CO2 are that (a) everyone is affected because the atmosphere does mix - the damage is not as localized as with mines (but don't get any misleading impressions, mines can affect a huge area) and (b) although we do know that the earth will warm, we don't understand enough yet to make accurate predictions of how that energy may be distributed - all we know with certainty is that there are many cases in which that warming will be a bad thing.

Bob @1:

I do share their skepticism about the role CO2 is playing in all this.

On what grounds?

I think it might be a kind of bizarre manifestation of open mindedness. One's willing to listen to the other side and the climate "skeptics" do give arguments that are superficially compelling. Enough so that their productions compare to that Al Gore's Oscar. If one is not really inclined to get to the bottom of things, an intelligent person might be fooled into thinking that there is some merit to the "skeptics'" nonsense.

When it comes to the understanding of AGW, there are the scientists who've been studying this for decades, among whom the overwhelming (over 95%) consensus is that global warming is real and is anthropogenic; and there are the "skeptics", who swallow the disinformation spread by self-interested merchants of doubt.

Forget Al Gore, follow the science.

If it matters at all, I've said that I'm skeptical that CO2 is the main driver of observed warming. That's a matter of its relative contribution to warming; not a matter of questioning whether it's a greenhouse gas. I'm skeptical because I don't think our understanding of the processes underlying warming is anywhere near complete -- and I don't think the incompleteness is a matter of simply filling in a few details. There are large gaps in our knowledge, such as the effects of land use changes on regional climate patterns. I don't think it's smart, scientifically speaking, to put all our eggs in the CO2 basket. Politics is yet another matter.

Bob
In the scientific world, stratospheric cooling is the proof that the current warming is caused by CO2.

Think of it this way, when you add extra blankets to the bed, the temp of the top blanket drops.

Thus GW cannot be from an increase in energy from the sun, but is from better insolation (CO2).

If you will not even address the strong evidence, then you really are just a merchant of doubt.

Notice the long flat bit on the end of the temperature graph, from 1998 onwards? That is the proof that CO2 is not the driver of the Earth's climate.

The true driver of Climate (at least on this timespan) is the strength of the solar magnetic field.

A strong relationship between solar activity and global climate has been understood by scientists for centuries. The original discoverers of sunspot cycles didn't have radioactive techniques to chart the sunspot cycle back into the past. They used the strong cyclic correlation between sunspot activity and food prices (warmer seasons == higher food production == lower food prices) to chart solar activity in previous centuries. Of course, the 19th century researchers who noticed this correlation had no way of knowing the reason - the fact that sunspot activity is a good proxy for solar magnetic field strength.

When the solar magnetic field is strong, it acts as an enormous forcefield protecting the inner solar system, deflecting cosmic rays, and preventing some of them from striking the Earth. This reduces cosmic ray seeded cloud formation, which increases global sunlight hours - the world warms.

When the solar magnetic field is weak, as it is now, more cosmic rays strike the Earth, and cloud cover rises. Clouds are highly reflective, and bounce a lot of sunlight back into space before it can warm the Earth. The Earth cools, and theories based on CO2 driven warming turn to mush.

The solar magnetic field / sunspot activity was weak during the Dalton Minimum. It was weak during the Maunder Minimum. And it is very weak now, as we approach a new Minimum.

http://en.wikipedia.org/wiki/Maunder_Minimum
http://en.wikipedia.org/wiki/Dalton_Minimum

Here is a good article on how high energy radiation can seed clouds.

http://en.wikipedia.org/wiki/Cloud_chamber

elspi - Did I say something about an increase in energy from the sun? Maybe you should worry less about "strong evidence" and pick up some basic reading/comprehension skills.

I'm not a climate scientist and I'm willing to accept the scientific consensus on this one, but I will say that I think people are engaging in a false dicotomy when answering Bob. He's just saying that CO2 might not be the only, or only important, factor. He's not saying that therefore the sun's energy is the answer.

I remember something I heard about this on CBC several years ago where they were discussing the effect of methane, which is a much worse greenhouse gas per molecule than CO2. Apparently young, newly growing trees put out a lot more methane than older trees, and therefore treating trees as a renewable resource and repeatedly cutting them down and replanting them is contributing significantly to global warming because the new trees are putting out enough methane to more than make up the greenhouse effect of the carbon dioxide they sequester. I have no idea if this is true or not (like i said, not a climate scientist), I just mention it to point out that just because someone said CO2 is not the be all end all of climate change doesn't necessarily mean they're a climate denialist or that they think the sun is getting hotter.

@bob: "I'm skeptical because I don't think our understanding of the processes underlying warming is anywhere near complete ..."

We know some processes extremely well; as far as CO2 goes we can put a lower limit on the increase in energy the earth system will retain based solely on atmospheric concentration. We also know that roughly half of human produced CO2 is retained in the atmosphere; we are less certain about whether the rate at which CO2 is taken out of the atmosphere can be maintained - there is an expectation that the capacity to remove CO2 from the atmosphere will eventually decline. We also know that claims of "more CO2 = faster growing/ bigger/ greener plants" is not a fixed fact but depends on many factors; overall we expect it to not be the case even though we have known for over 90 years that greenhouses flooded with CO2 (in the atmosphere or in the soil) can be beneficial to some plants in controlled conditions and in fact this technique is used in some places for growing certain flowers. Besides the CO2 enhancement in these controlled environments is far higher than what we would like in the global atmosphere. Unlike the planet earth, the environment in greenhouses is fairly easy to control. You haven't got such an option when you have extremely high CO2 concentrations in the earth's atmosphere.

What don't we know yet? Well, there's an awful lot. There is no good handle on the "enhanced effect" (feedbacks caused by addition of CO2) although so far there is only good evidence that the feedback mechanisms are a bad thing - no one has found or even thought of a feedback scheme that would reduce the warming. Well, no scheme has been proposed which agrees with reality anyway. So in addition to the "warming" due directly to CO2 we only expect a further, uncertain, additional warming.

The popularization of the phrase "global warming" has had bad effects as well. The earth system will retain more energy - whether or not that is a genuine warming in the short or medium term for any particular spot on the planet remains to be seen. For example, you can melt absolutely all ice on the planet's surface before you actually start raising the temperature of the system. So when scientists who know what they're talking about mention "global warming" they really mean an increase in energy of the system, not necessarily an actual warming somewhere. However, there is a genuine increase in temperatures somewhere on the globe, which is why the global mean temperature is calculated (and hence the somewhat misleading term global warming). We expect the global mean temperature to rise regardless of local conditions at any particular region on the planet, and this is indeed the case. If it weren't the case then we'd expect pretty much 100% of the minimum expected energy increase to go into melting ice. Eventually there will be widespread actual warming everywhere, but exactly when that will happen is anyone's guess. Another issue which is poorly understood is how that extra energy is distributed in the system. That in turn would determine local climate and weather, and as you can see from all the latest climate modeling, no one can currently make sensible predictions of the local climate (but short-term weather forecasting is very good). And there's one of the problems - people only see their local climate and in addition to that people have horrible memories when it comes to weather. If you've got time to waste, make notes of claims that people make about weather and check it against historical data for that area.

@Jake: I always offend my colleagues when they start talking about how methane is such a worse greenhouse gas than CO2. The rate of increase in atmospheric methane has to increase by a few orders of magnitude before it compares to the CO2 contribution. Part of the reason is that the average time spent by a methane molecule in the atmosphere is only a small fraction of the average time of a CO2 molecule in the atmosphere. That's not the worst of it either; many scientists get confused with this notion of "more effective greenhouse gas" and even get upset at the increase due to some more exotic chemicals invented by humans even though those chemicals have to increase by many orders of magnitude in the atmosphere before they even compete with the small annual increase in CO2.

Almost all methane formation involves reordering elements that are already in the biological system, either as things that are about to burn (in geological time) or things that just burned or the closely related decay process. Methane is a wild goose.

What matters is Carbon released from fossil sources where it was sequestered for the long term. Everyone needs to write out a version of that sentence and hang it on the bathroom wall across from the toilet so you see it every day and don't forget it. Even sequestering carbon in trees is medium term, unless the trees are in a subducting marshland that will later be covered by a thick deposit of delatic sediments from a major river system, or something along those lines.

From #12:
"Notice the long flat bit on the end of the temperature graph, from 1998 onwards? That is the proof that CO2 is not the driver of the Earth's climate."

About #12: "I am an IT Consultant..."

To #12: Why should your opinions trump the research?

Notice the long flat bit on the end of the temperature graph, from 1998 onwards? That is the proof that CO2 is not the driver of the Earth's climate.

It's not proof of anything besides that global temperature averages stabilized after 1998. What an embarrassing gap of logic.

The true driver of Climate (at least on this timespan) is the strength of the solar magnetic field.

Half-truth. It may indeed be A driver, not THE driver.

When the solar magnetic field is strong, it acts as an enormous forcefield protecting the inner solar system, deflecting cosmic rays, and preventing some of them from striking the Earth. This reduces cosmic ray seeded cloud formation, which increases global sunlight hours - the world warms.

When the solar magnetic field is weak, as it is now, more cosmic rays strike the Earth, and cloud cover rises. Clouds are highly reflective, and bounce a lot of sunlight back into space before it can warm the Earth. The Earth cools, and theories based on CO2 driven warming turn to mush.

And there is not a shred of direct evidence for any of that, is there? I almost died laughing when I first read about this crank idea.

What the hell is an IT consultant? Unless that is the same as a climatologist....

Enter the words solar magnetic field climate into Google and you will see a large number of references to the solar magnetic theory of climate variation.

The historical correlation between CO2 and climate is very weak, on both short and long timescales - much weaker than the correlation between solar activity and climate. As far as I know, none of the Warmist models predicted the current flat period - they all expected global temperatures to keep rising. Some of the sillier Warmists even predicted the end of winter snow.

http://wattsupwiththat.com/2009/12/29/crus-forecast-winter-snowfall-wil…

There have also been significant periods in the Earth's past when a high level of CO2 has coincided with a major drop in global temperature, such as the Carboniferous Age.

http://en.wikipedia.org/wiki/Carboniferous

As for me being an IT consultant - well I can tell you one thing which is within my field of expertise. The CRU climate model software revealed by the Climategate whistleblower is total junk. Anyone who thinks an amateur, my first program effort like the CRU software can effectively model a something as complex as global climate is deluding themselves. Any conclusions based on such rubbish are utterly unreliable.

http://wattsupwiththat.com/2009/11/25/climategate-hide-the-decline-codi…

> "That is from NOAA's new Climate Services site, where you too can mess around with the data"

That site is *very* user hostile, to someone who just wants to get an image - with refs - showing, e.g., past & expected temps from ~1900 to 2100 under business as usual.

Earth to NOAA - please create an image&graph library where the images&graphs have permalinks.