2011-09-21 11:55:36BLOG EXPERIMENT CONDITION 4: skeptic post, skeptic comments
John Cook


As the second part of our experiment on science blogging, we'll be showing 4 conditions to lab participants at the Uni of W.A. The condition for this thread is Skeptic Blog Post, Skeptic Comments. So would be great if a handful of SkSers could post glowing, very skeptic comments to our Denial blog post - posted here in this forum thread. We need exactly 10 skeptic comments.

Why we can chill out about global warming

Posted on 19 September 2001 by John Cook

People on either side of the climate debate agree climate change is happening. After all, climate has always changed. Several centuries ago, the Earth experienced a Little Ice Age where people ice skated on the Thames River in the UK. A millennium ago during the Medieval Warm Period, vikings settled in Greenland which obtained its name from the lush, green conditions at the time. If there is one truism that holds throughout Earth's history, long before the invention of SUVs and plasma televisions, it's that climate changes. So the key question of the climate debate is this - are humans causing global warming now?

Many scientists say no. Over 31,000 scientists have signed a petition saying there's no evidence that greenhouse gases are causing global warming. Eminent climate scientists such as Richard Lindzen, Roy Spencer and John Christy, who have published hundreds of peer-reviewed papers between them, argue that human activity will not have a significant effect on climate. Climate change is still hotly debated among scientists, indicating the science is not settled. To make expensive societal changes or spend significant taxpayer money on climate regulation before the scientists have even made up their mind is rash.

What are some of the points of contention among scientists? The 31,000+ scientists who signed the OISM Petition argue that it's wrong headed to label carbon dioxide a pollutant. Carbon dioxide is a naturally occurring gas. It's invisible, non-toxic and you can't smell it. On the contrary, if there was no carbon dioxide in the air, every plant in the world would die. Carbon dioxide is plant food. To claim that carbon dioxide is a pollutant goes against biology and common sense. Carbon emissions will improve plant growth and are a welcome addition to our environment.

A rhetorical technique by climate alarmists is the use of large, misleading numbers to frighten people. They talk about carbon dioxide levels at 390 parts per million as if this is a high, unusual amount. However, what the layperson doesn't realise is this is equivalent to only 0.039% of the atmosphere. This is an historically small fraction, with CO2 levels having been much higher in the past. During the Ordovician-Silurian periods, some 450 million years ago, CO2 levels were a staggering 4000ppm. This is more than 10 times greater than current levels and yet the Earth didn't burn away in a runaway greenhouse effect. During the late Ordovician, the Earth slipped into an ice age while CO2 levels were much higher than today's levels. To claim carbon dioxide is the main driver of climate is to ignore much of Earth's history.


In fact, carbon dioxide is not even the strongest greenhouse gas in the atmosphere. The strongest greenhouse effect comes from water vapor. This is confirmed by empirical measurements that observe that the warming effect from water vapor is around double the warming effect from CO2 (Evans 2006). It's imperative that more attention is paid to trends in water vapor as this is a much more significant contributor to surface temperatures.

A key driver of climate is variations in solar activity. The sun provides almost all the energy in our climate system. Consequently, our climate is sensitive to changes in the sun's output. When the sun gets warmer, our planet accumulates heat and experiences global warming. Over the last few decades, the sun has been unusually warm, achieving it's warmest levels in 1,150 years (Usoskin 2005). The unusually warm sun has coincided with an unusually warm Earth. Considering the close relationship between solar activity and climate, it's no wonder climate scientists downplay the role of the sun. Much has been made of the hockey stick in the temperature record but curiously, no mention is made of the hockey stick in solar activity.

Top: Solar Activity measured by sunspot numbers (solid line) and 10Be data (dotted line) from Usoskin 2005. Bottom: Reconstructed Northern Hemisphere Land Temperature from Moberg et al 2005.

Another dominant player in climate change is internal variability. Our climate is not static. Powerful ocean cycles drive large exchanges of heat between the ocean and the atmosphere. The strongest of these cycles is the El Nino Southern Oscillation which has a discernible impact on global temperature. Over periods of months, the Pacific Ocean can switch from El Nino conditions to La Nina conditions, causing cooling which wipes out decades of gentle warming from CO2. More subtle but no less important are longer cycles such as the Pacific Decadal Oscillation (PDO) which switches every couple of decades. Global temperature trends correlate closely to the PDO. In contrast, CO2 rose mid-century while global temperatures fell. The lack of correlation with CO2 and the high correlation with the PDO speaks of a stronger relationship between climate and the oceans - unsurprising considering the oceans form a major part of our climate system.

So we see many natural contributors to climate change that are significantly more dominant than the invisible, insignificant trace gas carbon dioxide. Nevertheless, there is an agressive push for costly carbon regulation. This is because there is no revenue to be made from blaming climate change on nature. We can't pay a sun tax to control solar activity. We can't put a price on ocean cycles to regulate the El Nino Southern Oscillation. It's a human impulse to desire control over our environment. However, Earth's long history and empirical evidence tells us climate change is out of our control.

2011-09-21 13:29:12
Alex C


>>>no mention is made of the hockey stick in solar activity.

Of course not John, because it clearly demonstrates that the Sun drives the climate.  Excellent comparison between temperature and solar activity, this *should* be the clincher here in the debate but unfortunately, as you said, these facts are played down.  The trend even matches back to a millennium ago, you can tell that there were dips in solar activity during 1500-1700, and a concomitant low in temperatures; and also higher levels centuries before with (gasp!) higher temperatures.

Now let's all put on our thinking caps, folks, and do what the IPCC and global warming alarmists refuse to do (or are unable to do).

2011-09-21 14:09:44


The Arctic ice is currently melting a bit more than usual because of the Gulf stream being warmer.  The Gulf Stream gets its heat in the tropics and carries it up north.  According to the models, CO2 should be making the poles warmer, but its the tropics that are warming otherwise the Gulf Stream couldn't be getting any warmer.  Epic fail for the models,  wouldn't you say?



2011-09-22 05:41:34
Steve Brown


It makes me angry that real gentlemen scientists like Dr Lindzen and Dr McIntyre can't get the research in this post through pal review.  It makes me sick to think the world is being hoodwinked by charlatans in their university cabals - rmember climategate?

Great work John on showing that the science isn't settled.

2011-09-23 12:56:00Smoking Gun
Glenn Tamblyn


This has always been the 'smoking gun' against the warmist's disaster hypothesis. If CO2 is supposed to change climate, how could there have been so much CO2 in the past when temp's weren't running away, or causing ice ages? Unless of course CO2 doesn't do what they speculate it does. Perhaps thats why CO2 lags Temperatures in the Ice core data.

2011-09-24 17:45:21

Good point re the co2 lag. Not only was co2 higher in the past, it also lags temperature, showing temperature drives co2, not the other way around. The ice core record is not kind to the warmist agenda.
2011-09-24 21:33:58


I always had a hunch which this post really confirms: we don't need to worry about this so called global warming! Let the "climate scientists" wail all day long how bad it already is and how much worse it will get - they just do that to earn tons of money but don't have a leg to stand on. Haven't you heard? CO2 is plant food! We can't take it away from them, they'd starve and wilt. 31,000 real scientist can't be wrong, can they?

2011-09-25 12:28:04
Dana Nuccitelli

The alarmists keep saying the science is settled and all the scientists agree.  But I haven't seen them come up with a list of 31,000 scientists who agree that humans are causing global warming.  Over 9,000 of the skeptic scientists on that list have PhDs too!

The article also does a great job proving that CO2 is just a trace gas.  Alarmists want us to believe that a trace gas at 0.03% of the atmosphere is causing catastrophic global warming?  How stupid do they think we are?!

2011-09-25 19:02:12

Good point re the number of scientists. The alarmists like to boast about there being 2500 scientists who wrote the IPCC report. But the number of skeptic scientists is AN ORDER OF MAGNITUDE greater than the number of alarmist scientists. Not only there is still a debate, the weight of opinion leans heavily towards the skeptic point of view. This article presents the compelling evidence that explains why.
2011-09-25 19:03:12
Rob Painting

Developing a split personality are ya?

2011-09-26 07:53:36
Steve Brown


Regarding my above comment, I of course should have included Dr Motl as on one of those fine gentleman scienteists.  Dr Motl - I'm honoured to be posting in the same thread as you!

2011-09-26 13:24:12Note re Lubos Motl
John Cook


I won't use the name Lubos Motl or any of our names in the final webpage used in the experiment (so the last two comments by Rob and Steve won't be used, I'm afraid).

2011-09-26 14:56:18The GH Effect is IMPOSSIBLE!!
Glenn Tamblyn


What these so called 'climate scientists' don't get is that their so called GreenHouse Effect can't work the way they think it does. They say it works like this: The Earth absorbs heat from the Sun then Radiates it back again trying to send it out to space - So far so good. If that didn't happen the Earth would just get hotter and hotter. Then CO2 (and don't forget water vapour! The warmists usually just ignore that) absorbs some of this, stopping it from getting out to space. Well, yeah, maybe. Then some of this heat gets radiated by the CO2 BACK DOWN TO THE EARTH AGAIN!!! Say What!

Haven't these guys ever heard of the 2nd Law of Thermodynamics! The air is colder than the Earth. HEAT CANNOT FLOW FROM A COLD THING TO A HOT THING!!!! Its Impossible. Because this was drummed into us back when I did my Degree in Mechanical Engineering many years ago. I might only have a lowly Batchelors degree, not some PhD or anything but even I know this is impossible. My old lecturer would have been hurling the blackboard duster at me if I had suggested something this STUPID.

How much do we pay these guys?

2011-09-26 15:03:11For the record, that makes 9 comments, one to go
John Cook


Glenn, just curious, did you intentionally misspell "Bachelors degree"? Getting too much into character? :-)

2011-09-26 15:06:41Umm, Urrgghh
Glenn Tamblyn





.... Yes John, of course I did. What else?

2011-09-26 18:15:25Yes CO2 is a greenhouse gas but...
Glenn Tamblyn


One small problem with the AGW hypothesis. Yes CO2 is a greenhouse gas, just as they say. Amd no its not the only one, which they sometimes 'forget' to mention. But...

CO2 is just about  tapped out. Adding CO2 is going to have very, very little EXTRA effect. This is because of something called Saturation. This is a bit complicated so stay with me.

CO2 absorbs in certain ranges of the Infra-Red spectrum - every chemistry major knows that. This is a bit like saying that it absorbs just the yellow in the visible light spectrum. Think of it as absorbing the Infra-Red version of 'yellow'. And that is why it has contributed to the GH Effect so far. However, the amount of CO2 in the atmosphere actually absorbs nearly ALL the light in this IR 'yellow' range. So adding more CO2 just doesn't do much more since it has already pretty much done the job already. You can't absorb much more if you have already absorbed most of it already.

This is why we have the climate that we do. Scientists say that if we didn't have CO2 in the atmosphere the Earth would be a giant Snowball - They even use the term 'snowball Earth'. And they might be right. But, BIG but. CO2 has done its job and the Earth isn't a snowball. But it is all tuckered out and just can't do any more. Which is just as well for us. It stopped us from freezing then steps aside to stop us from boiling.

Pretty neat huh? You might almost think it was designed to work that way.

2011-09-26 18:24:30
John Cook

Nice finish, Glenn :-)

This thread is now finished, and I'll deliver the 4 conditions to the cognitive Boffins tomorrow. Many thanks, all!