2011-09-21 11:54:10BLOG EXPERIMENT CONDITION 3: skeptic post, warmist 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, Warmist Comments. So would be great if a handful of SkSers could post scathing, very warmist comments to our Denial blog post - posted here in this forum thread. We need exactly 10 warmist 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 14:30:07


There is so much wrong with this article that I'll just address one simple point: I'm sure you will get plenty of takers for the rest.


Greenland was a very small colony.  It had grass when it was settled, it had grass when it was abandoned and it has grass now.  As explorers discovered more and more coast they kept calling it Greenland.  And so it happens by an accident of history that the entire land contiguous with that first Viking settlement is now called Greenland.  It is ludicrous in the extreme to suggest, or even hint, that the entirety of Greenland was green in the age of the Vikings.  You may as well claim that South Africa's Orange River was full of oranges in the days of the Zulu Wars.

2011-09-22 05:33:07
Steve Brown


I've often thought that all climate skeptics occupy a place on a spectrum between credulous stupidity and completely evil lying.  If anyone here has a single ounce of rationality and who wants to be a genuine skeptic the you can do no wrong than to have a read of this:  The Discovery of Global Warming by Spencer Weart.  At the very least it will make your skepticism better informed.

2011-09-23 12:52:13Deep Climate
Glenn Tamblyn


Was CO2 that much higher 100's of millions of years ago? Yes. Does this mean that CO2 has no effect? No.  Why? Because like many skeptic arguments, this ignores some basic evidence. In the distant past the Sun was COOLER! Over its 4.5 billion year life the sun has increased its heat output by 30%. If you don't take this into account when looking at the distant past you can easily reach the wrong conclusion. Extra CO2 was needed to compensate for the fact that the Sun was cooler. Rougly speaking, when we go back in time, CO2 levels need to have been double every 150 million years just to keep temperatures high enough.

And CO2 was lower during the Ordovician, low enough to cause an Ice Age. Reports that it wasn't aren't using the most recent geological data.

So, the claim carbon dioxide is the main driver of climate is BASED on much of Earth's history.

It is way too easy to get the wrong take on something when we aren't given all the facts. What is the old saying about lying - 'Tell the Truth. But not all of it'!

2011-09-24 22:02:15


Just mentioning the OISM petition signed by more than 31,000 scientists - and giving that any weight - is a sign that a lot is wrong with this post! For one, only a very small number of those 31,000 scientists were really working climate scientist, but most were working on totally differnt subjects (not to mention that there are obviously fake entries as well!).

One could say that this post is cherry-picking at its best with concentrating on just a few points but leaving out the complete picture. Even though it is true, that CO2 makes up only a very small amount of our overall atmosphere, you have to take a closer look: Most of the gases in our atmosphere don't have heat-trapping properties so you can safely ignore those inert gases like Oxygen and Nitrogen and only look at CO2 in comparison to its "buddies", the other greenhouse gases. What you'll find is that the "tiny" amount of CO2 makes up about 25% of those and that is certainly nothing to ignore!

2011-09-25 12:24:30
Dana Nuccitelli

Water vapor is actually a very weak greenhouse gas.  The only reason it accounts for much of the greenhouse effect is that there's a lot of it in the Earth's atmosphere.  But the amount of water vapor in the atmosphere depends on the temperature of the atmosphere - if the planet isn't warming, the amount of water vapor won't increase.  Water vapor itself doesn't cause global warming, it can only amplify global warming (a.k.a. a 'feedback') caused by other factors.  Right now, the warming is caused by the increased greenhouse effect due to human greenhouse gas emissions.

Unfortunately this article is riddled with these misunderstandings of basic climate science.

2011-09-25 20:28:28

It's hilarious that this article cites Usoskin 2005. That paper concludes that over the last few decades, the correlation between sun and climate breaks down. Therefore, recent warming must have some other cause. This article's own sources debunk its assertion that the sun is causing global warming!
2011-09-26 04:25:10
Alex C


What's worse is that anyone who has ever bothered to take a look at solar output graphics (to get a more quantitative idea of solar output, rather than just solar spot numbers, which are good but don't communicate the finer details) would know that TSI has only increased by <1 Watt/square meter since the start of the Industrial Era.  Since TSI doesn't translate directly into forcing - because you have to take into account spherical geometry and albedo - the actual forcing due to CO2 is less than a fifth of a Watt/m^2.  Compare that to the 1.77 W/m^2 increase from CO2; again, you're telling half the story but not all.  Solar hockey stick yes, but it's not going to be scoring any slapshots anytime soon.

2011-09-26 13:26:55
Glenn Tamblyn


"However, what the layperson doesn't realise is this is equivalent to only 0.039% of the atmosphere"

Gee, sounds pretty small doesn't it! ONLY 0.039%. But what the article doesn't mention is that is more than enough cO2 to have quite an impact. Laymen don't realise just how MANY molecules their actually are in a chunk of Air. If you take a patch of ground 1 metre square, the air above it up to your waist, 1 cubic metre contains 10 thousand million million milllion CO2 molecules. And that much again in the cubic metre above that, and above that, and above that, and... You get my drift. This is more than enough CO2 to have quite an impact.

Again, they 'Tell the Truth. But not all of it'!

2011-09-26 13:32:34


The full truth about the percentage of CO2 is that over 99% of the atmosphere is oxygen and nitrogen, both gases which are not greenhouse gases. So the fact that CO2 is a small percentage is irrelevant to the strength of its greenhouse effect. It's like holding an election in a town of 1000 people where only 10 people vote. They may only be a small number but each individual has a significant effect. It's the same with CO2. Of course, you don't have to take my word for it - what do measurements find? Both planes and satellites measure heat as it escapes to space and both find a big bite out of the outgoing heat, at precisely the wavelengths that CO2 absorbs heat. The greenhouse effect is an empirically observed fact.

2011-09-26 14:26:05
Glenn Tamblyn


And if you really don't want to take our word for it, go ask the US Defense Department. They have been behind research into the properties of CO2 among other gases since WWII. Because its really important to them that they know how light, including InfraRed light, REALLY travels through the atmosphere. It matters when you are designing Infrared Air-To-Air missiles, Star-Wars airborne lasers or Early Warning Satellites. Just think - WWIII didn't happen because a satellite didn't confuse a lightning strike in Siberia with a missile launch. Because the DoD understands how CO2 works REALLY WELL!

The most commonly used computer program for calculating light transmission through the atmosphere is called ModTran. It is used for the sorts of calculation done in Climate Science. And also for missile seeker head designs, observation satellites, astronomical observation of other planets. And designing your microwave oven! Around 1/2 the Patents covering how ModTran works are owned by the US DoD.

So if you think AGW isn't real, go ask them. They spent a lot of money finding out the basic science of it all. And I don't think a bunch of hard-nosed Generals are Tree-Hugging Greenies, do you? If CO2 isn't a problem, why is the Military making plans for the new security threats in a warmer world?

2011-09-26 14:29:15Thanks, this thread is finished
John Cook


Thanks all, got my 10 comments so no need to post to this one any longer. Much appreciated! :-)

2011-09-26 14:43:59I'll add a thumb
John Cook


Just for completeness.