Carbon Emissions Don’t Cause Global Warming

Dr. David Evans

Background
A paper I wrote that briefly describes the history of why we used to believe that carbon
emissions caused global warming, and how we got to where we are now in the debate
is found on the following website:
http://mises.org/story/2571 

Ice Core Data Reverses — 2003
First crucial point, 2003. We've all seen Al Gore’s movie. It was the early, low
resolution ice core data first gathered in 1985 that convinced the world that CO2 was
the culprit: CO2 levels and temperature marched in rose and fell in lockstep over the
last half a million years, to the resolution of the old ice core data (results from 1985 –
2000, data points over a thousand years apart). It was ASSUMED (bad assumption #1)
that CO2 levels controlled the world’s temperature.

After further research, new high resolution ice core results (data points only a few
hundred years apart) in 2000 – 2003 allowed us to distinguish which came first, the
temperature rises or the CO2 rises. We found that temperature changes preceded CO2
changes by an average of 800 years. So temperature caused the CO2 levels, and not the
other way around as previously assumed. The world should have started backpedalling
away from blaming carbon emissions in 2003:

http://www.noe21.org/dvd2/Global%20Warming%20FAQ%20-%A0%20temperature.htm 

Greenhouse Signature Missing — 2007

Second crucial point, August 2007. There are several possible causes of global
warming, and they each warm the atmosphere at different latitudes and altitudes —
that is, each cause will produces a distinct pattern of hot spots in the atmosphere, or
“signature”. The greenhouse signature is very distinct from the others: warming due to
greenhouse would cause most warming in the tropics at about 10 km up in the
atmosphere:

Theoretical Greenhouse Signature (UN climate models)
As of August 2007 we’ve measured where the warming is occurring in a fair bit of
detail, using satellites and balloons. The observed signature is nothing like the
greenhouse signature — the distinct greenhouse signature is entirely missing:

Observed Warming (Hadley Centre radiosonde observations 2006,
confirmed by more measurements published in 2007)

There is no hotspot in the tropics at 10 km up, so now we know that greenhouse
warming is not the (main) cause of global warming — so we know that carbon
emissions are not the (main) cause of global warming.

Of course these observations need to be repeated by other researchers before we can be
completely sure, but they are made by top-notch researchers and reported in top-of-the-
line peer-reviewed journals so at this stage they look solid. This article from
August 2007 is a hard read, but the results are new, it is the most accessible on the web
so far, and is much easier to understand than the raw scientific papers:
http://scienceandpublicpolicy.org/images/stories/papers/monckton/whatgreenhouse/moncktongreenhousewarming.pdf 

Where the IPCC Models Went Wrong — 2007

So why did we go wrong? Another set of recent observations show why the UN
climate models got it wrong.

Doubling atmospheric CO2 from the pre-industrial level of 280ppm up to 560ppm
(which is roughly were the IPCC says we will be in 2100) is calculated to raise the
world’s air temperature by up to 1.2C in the absence of feedbacks such as convection
and clouds. This is what you would get if the air was in a flask in a laboratory.
Everyone roughly agrees with that calculated result.

But the modellers ASSUMED (bad assumption # 2) that increased warming would
cause more rainfall, which would cause more clouds high up in the atmosphere — and
since high clouds have a net warming effect, this would cause more warming and thus
more rainfall and so on. It is this positive feedback that causes the UN climate models
to predict a temperature rise due to a rise in CO2 to 560ppm to be 2.5C - 4.7C (of
which we have already experienced 0.7C).

But in September 2007 Spencer, who spent a few years observing the temperatures,
clouds, and rainfall, reported that warming is actually associated with fewer high
clouds. So the observed feedback is actually negative, so we won't even get the full
1.2C of greenhouse warming even if carbon levels double!

As Spencer says with such understatement: "Global warming theory says warming will
generally be accompanied by more rainfall. Everyone just assumed that more rainfall
means more high altitude clouds. That would be your first guess and, since we didn't
have any data to suggest otherwise ...". Science is about observational evidence
trumping theoretical calculations, which is exactly what is happening here:

http://www.uah.edu/News/newsread.php?newsID=875 

Warming Already Waning
The only temperature data we can trust are satellite measurements, and they only go
back to 1979. They show no warming in the southern hemisphere, and the warming
trend in the northern hemisphere appears to have waned since 2001:

Global Satellite temperatures (1979 – late 2007)
http://www.junkscience.com/MSU_Temps/RSSglobe.html 
http://www.junkscience.com/MSU_Temps/RSSNHem.html 
http://www.junkscience.com/MSU_Temps/RSSSHem.html

(Gratuitous advice for those whose jobs depend on the idea that carbon emissions
cause global warming: Find another job to pay your mortgage and feed your kids!)

Three Stages of Knowledge and the IPCC
Our scientific understanding of global warming has gone through three stages:

1. 1985 – 2003. Old ice core data led us strongly suspect that CO2 causes global
warming.

2. 2003 – 2007. New ice core data eliminated previous reason for suspecting CO2.
No evidence to suspect or exonerate CO2.

3. From Aug 2007: Know for sure that greenhouse is not causing global warming.
CO2 no longer a suspect.

The IPCC 2007 report (the latest and greatest from the IPCC) is based on all scientific
literature up to mid 2006. The Bali Conference is the bureaucratic response to that
report. Too bad that the data has changed since then!