Who is right and who is wrong in the ongoing Climate War?

Imagine that a Martian arrives on earth and, being obviously uncontaminated with the details of the debate going on regarding man made global warming, is asked to adjudicate on the strength of the arguments put forward by the pro- and anti-AGW sides.

In a massive blow to interstellar relations, our Martian friend is forced to sit through Al Gore's An Inconvenient Truth.

Initially, he is impressed. The correlation between CO2 and temperature does indeed seem to be high.

He then sits though a presentation by Bob Carter - the irrepressible Australian scientist (BTW - the term is tautologous, as all Australians are irrepressible) - and discovers that ice core analysis demonstrates conclusively that CO2 lags temperature.

Not to be outdone by such pesky details the Climate Faithful roll out the high priest of climate science himself, James Hansen. Hansen then describes how climate models work along with their predictions of serious temperature rises over the next one hundred years.

Again, our Martian friend is impressed. On Mars, people who can plot lines on bits of paper are held in high regard.

Roy Spencer then appears for the nay sayers and blows the Martian away by plotting two lines on a graph - one with the model predictions and, tellingly, one with observed temperatures.

Now our Martian friend is getting really confused. Who to believe?

Michael Mann then takes the stage and outlines the inconic Hokey Stick, showing that modern temperatures are unprecedented in the history of the world. His presentation is backed up by the head of the UN IPCC, Dr Rajendra Pachauri, who highlights the prominence of Mann's work in IPCC publications.

Impressed by more lines, and bendy ones at that, our Martian gives weight to Mann's presentation. He doesn't know what a Nobel Peace Prize is but he recognises that it must be important.

Enter Steve McIntyre who proceeds to thoroughly demolish the scientific legitimacy of the Hokey Stick. McIntyre demonstrates that Mann's algorithm can be used to produce a hockey stick by using red noise data. Supporting McIntyre is Edward Wegman, chairman of the US National Academy of Science's committee on applied and theoretical statistics.

Now thoroughly confused, our Martian friend decides to take a break before hearing more testimony.

So which side will he choose?

Who knows?

What's clear, though, is that the science is somewhat less than clear, is clearly not 'settled', a consensus does not exist and, critically, the so-called 'deniers' have a high degree of scientific credibility.

Over the last couple of years there has been an increasing body of scientific work demonstrating that other factors are more responsible for the change in the world's temperature than CO2 including solar activity and the effects of the El Nino Southern Oscillation and Atlantic Multidecadal Oscillation.

Entering the argument is a piece of analysis by Bill Illis, posted at Watts Up With That, that adjusts temperatures for the ENSO and AMO. Be sure to read the whole thing. It will be intriguing to see how long it takes for the Climate Faithful to strike back at Illis's thesis.

The result of his work is pretty interesting, as it provides a more accurate explanation of temperature variation than do climate models.

People have noted for a long time that the effect of the El Nino Southern Oscillation (ENSO) should be accounted for and adjusted for in analyzing temperature trends. The same point has been raised for the Atlantic Multidecadal Oscillation (AMO). Until now, there has not been a robust method of doing so.

This post will outline a simple least squares regression solution to adjusting monthly temperatures for the impact of the ENSO and the AMO. There is no smoothing of the data, no plugging of the data; this is a simple mathematical calculation.

Some basic points before we continue.

- The ENSO and the AMO both affect temperatures and, hence, any reconstruction needs to use both ocean temperature indices. The AMO actually provides a greater impact on temperatures than the ENSO.

- The ENSO and the AMO impact temperatures directly and continuously on a monthly basis. Any smoothing of the data or even using annual temperature data just reduces the information which can be extracted.

- The ENSO’s impact on temperatures is lagged by 3 months while the AMO seems to be more immediate. This model uses the Nino 3.4 region anomaly since it seems to be the most indicative of the underlying El Nino and La Nina trends.

- When the ENSO and the AMO impacts are adjusted for, all that is left is the global warming signal and a white noise error.

- The ENSO and the AMO are capable of explaining almost all of the natural variation in the climate.

- We can finally answer the question of how much global warming has there been to date and how much has occurred since 1979 for example. And, yes, there has been global warming but the amount is much less than global warming models predict and the effect even seems to be slowing down since 1979.

- Unfortunately, there is not currently a good forecast model for the ENSO or AMO so this method will have to focus on current and past temperatures versus providing forecasts for the future.

And now to the good part, here is what the reconstruction looks like for the Hadley Centre’s HadCRUT3 global monthly temperature series going back to 1871 - 1,652 data points.

Here are a couple of graphs that show the problem not only with climate models but also the science that they are based on (click to see a larger version).

The first shows the Hadley data in blue and Illis's ENSO/AMO model in red.

The second shows the temperature record plotted against what global warming theory expects (green), the trend and a simple model.

It's clear that climate science is in serious trouble.

A doubling of CO2 does not lead to a doubling in temperature, as shown below:

...and the end expanded as follows:

Observed temperatures are not in line with models' predictions.

Not by a long shot.

Climate science is based on greenhouse gasses being a forcing agent, which is then amplified by a feedback mechanism, water vapour.

The fact that temperatures are not responding in the way that is predicted by climate science proves conclusively that even if CO2 is primarly responsible for the world's warming then the understanding of the forcing/feedback relationship is not well understood.

Our poor old Martian certainly does have his work cut out for him deciding between the two sides.

No wonder the general public is confused.

(Nothing Follows)