Already in the first paragraph, mis-statements of fact.

1998 was the year of the strongest recorded el Nino. 2010 was not an el Nino year, in fact in the latter half of the year a strong la Nina developed, rated by some as the strongest ever.

So, 2010 was the equal-hottest on record, *despite* a strong, cooling la Nina in the second half, whereas

1998 was equal-hottest on record partly *because* of a strong, warming el Nino.

Actually Geoff 2010 was an el Nino year, but a la Nina also developed very quickly. One of the surprises was how it remained hotter for a while longer after the la Nina took over but then there was always been considerable variation in temperatures, month to month. Certainly there has been no warming trend of any note since 1998, as the author points out.

Also the author should be congratulated on being one of the few to realise that the whole argument has been about the feedback effect of water vapour in the upper atmosphere. This was an assumption built into the earlier models that never went away, but has never been proved or even seriously questioned - in part because the vast bulk of even the scientists who support global warming have no idea it exists.

For a researcher Geoff Davies' misleading comments on Alex Stuart's piece are disturbing. 2010 was an El Nino year with the change to La Nina occurring suddenly in April. Global sea surface temperatures commenced to decline thereafter, as expected. Atmospheric temperatures remained high for 5-7 months after the switch which which peer-reviewed research indicates would be the case. After this time lag global tropospheric temeratures started to decline in October, with a negative anomaly with respect to the 1981-2010 average, being reached in January.

I don't understand how you can claim that '2010 was an El Nino year' if there was a 'change to La Nina occurring suddenly in April'. How is an El Nino 'year' defined? On the face of it we seem to have had a less than 1/3 El Nino Year and a more than 2/3 La Nina Year.

Malrob - interested in your comment that atmos temps were expected to remain high for a time after the switch to la nina .. I wasn't aware of those forecasts so I expected them to fall sraight away .. I'm prepared to be instructed.. do you have a couple of references I can look at??.

Mark - the specific reference I was quoting was McLean, J. D., C. R. de Freitas, and R. M. Carter (2009), Influence of the Southern Oscillation on tropospheric temperature, J. Geophys. Res., 114, D14104, doi:10.1029/2008JD011637.

Abstract - Time series for the Southern Oscillation Index (SOI) and global tropospheric temperature anomalies (GTTA) are compared for the 1958−2008 period. GTTA are represented by data from satellite microwave sensing units (MSU) for the period 1980–2008 and from radiosondes (RATPAC) for 1958–2008. After the removal from the data set of short periods of temperature perturbation that relate to near-equator volcanic eruption, we use derivatives to document the presence of a 5- to 7-month delayed close relationship between SOI and GTTA. Change in SOI accounts for 72% of the variance in GTTA for the 29-year-long MSU record and 68% of the variance in GTTA for the longer 50-year RATPAC record. Because El Niño−Southern Oscillation is known to exercise a particularly strong influence in the tropics, we also compared the SOI with tropical temperature anomalies between 20°S and 20°N. The results showed that SOI accounted for 81% of the variance in tropospheric temperature anomalies in the tropics. Overall the results suggest that the Southern Oscillation exercises a consistently dominant influence on mean global temperature, with a maximum effect in the tropics, except for periods when equatorial volcanism causes ad hoc cooling. That mean global tropospheric temperature has for the last 50 years fallen and risen in close accord with the SOI of 5–7 months earlier shows the potential of natural forcing mechanisms to account for most of the temperature variation.

Candide - direct El Nino for the first few months and then 7 months of lag before La Nina starts to reduce temperatures. Sounds like an El Nino controlled year to me.

A long, long, time ago

In first-year chemistry (for engineers)...

I was required to perform a lab "experiment" (really a demonstration of principle), based on our previous experiment, the Bomb calorimeter.

In this subsequent and marginally more advanced "experiment", rather than merely assessing the outputs of a first-order exothermic reaction, we were required to monitor the *temperature* of a mixture of materials in the presence of a reaction that produced a previously calibrated amount of "heat" (really "energy" that the simpler system registered as increased temperature). The more complex system involved not just a liquid and a negligible gas volume, but a large gas volume, some liquid and in later segments of the experiment, some ice.

It was noted that there were:
Pressure differences, suggesting a change of state.
Volume differences in the fluid, suggesting thermal expansion, neglecting evaporation.
A reduction in the mass of ice, and in it's density (achieved by only one lab group due to careful technique).
Barely significant (in terms of measurability) change in average temperature.

The same amount of "heat" still went in.

What happened when the thermal buffers were exhausted, you ask?

The bacteria died.

Rusty.

Malrob - tnks for that.. will look..

Curmudgeon
And also look up the complete debunking of McLean and Carter.

Peter A. when the debunkers come up with a forecast as accurate as that of deFreitas, McLean and Carter then maybe I will believe them. But I am still waiting.

And what 'accurate forecast' would that be exactly, malrob?

>> when the debunkers come up with a forecast as accurate as that of deFreitas, McLean and Carter then maybe I will believe them. But I am still waiting. <<

For the onlookers, it's worth checking out the rebuttal paper:

http://www.jamstec.go.jp/frsgc/research/d5/jdannan/comment_on_mclean.pdf

This piece at the ABC's Drum says more, but I find the comments most enlightening, particularly as you get involved malrob:

http://www.abc.net.au/unleashed/33364.html

Malcolm Roberts (malrob), in your recent open letter to Professor Karoly you write:

"In recent years, as well as learning more about climate I have been learning more about true forgiveness ... Associated with the power of forgiveness, the work of Marshall Rosenberg and my own personal experience shows that knowing one's needs and identifying another person's needs enables both to find ways to fulfill their real needs ... After understanding your needs I'm confident I will be able to assist you in meeting your needs"

Can I ask; how do you think Professor Karoly should respond to you?

Well, as a total non scientist it is a pleasure to see a sensible
discussion on this subject among those that seem to know a lot more
than I do.

I have a question;
Will the more realistic amounts of hydocarbon fuels, ascertained by
the Uppsala Universities Global Energy Systems Group, to be
significantly less than the amounts used by the IPCC computer models
make a significant difference to the IPCC findings ?

If water vapour has a negative effect, are all the CO2 regulations
and projects a total waste of time and money ?