G’day Keiran, good to see OLO’s resident ‘cosmic-ray enthusiast’ flying the flag!

The Keenlyside et al paper that was published in Nature was bound to bring the ‘AGW-deniers’ out of the woodwork.

'Deniers' have been rubbishing the climate models (GCMs) without really understanding the difference between ‘weather’ and ‘climate’. Yet now they use this new Keenlyside model to ‘justify’ their (wrong) claims of global cooling – very hypocritical methinks.

However, I don’t think they really understand the paper that was published. Policy and decision makers around the globe have wanted to plan and develop strategies that will help them adapt to climate change and mitigate the impacts of CO2e emissions.

Filtering out ‘signal to noise’ (as it relates to climate change prediction, as opposed to weather forecasting) requires time frames in the order of decades. What Keenlyside has done is ‘predict’ say 10 years out. This would be extremely beneficial to the policymakers, particularly for regional planning.

What this paper has done is help ‘explain’ the influence of natural variability of the Pacific Decadal and North Atlantic Oscillations superimposed on anthropogenic global warming. Indeed, the authors say their modelling method was able to reasonably replicate climate patterns in those regions in recent decades, providing some confidence in their prediction for the next one.

The authors stressed that the pause in warming represented only a temporary blunting of the centuries of rising temperatures that scientists have projected if carbon dioxide and other heat-trapping gases continue accumulating in the atmosphere.

“We’re learning that internal climate variability is important and can mask the effects of human-induced global change.”

Looking at the graph in the link I provided, you can still see the warming trend to 2100. It’s disingenuous at best and outright distortion at worst to say ‘global warming’ is no longer occurring, but this is exactly what the AGW-deniers are saying.

A link to the abstract can be found here:

http://www.nature.com/nature/journal/v453/n7191/abs/nature06921.html

BTW, Wikki is ‘generally’ ok for an overview (especially for beginners) BUT I prefer to read the published papers in the Journals I have linked to in other OLO threads.

Plerdsus

There is so much fuss because the impacts of global warming have repercussions around the world: national/international security, energy use and food supply, water resources, biodiversity, insurance and risk management, monetary/fiscal policy – add your own list.

All countries and governments of the world are concerned – why would they not be? How we deal with the problem is the problem, not the science per se.

Peak oil (hydrocarbons) is an issue, but it is wrong to suggest it’s “going to kill that stone dead in the very near future.” We should make more prudent use of our oil resources. When oil is gone, there will be other ‘oils’ (see tar sands and shale oil for example). It’s the burning of fossil fuels and poor land use management practices that mainly contribute to AGW.

The theory of AGW suggests humanity has been the major (not the only) driver of this latest global warming. While climate change is a naturally occurring event over ‘geologic time’ periods, this latest one is of concern because of its relatively abrupt rate of change and the impact a GMT change of say 2 degrees will have.

There will be a lot of research done in the next few years on what is called attribution/commitment (natural vs human induced forcings) and climate sensitivity (how much warming for a particular increase in GHG concentration).

It is NOT about “how many degrees does the average temperature have to fall for us all to agree that global cooling is a fact”. Rather, it’s about trends and statistics (those damn statistics). See previous comment to Keiran.

These links are worthwhile cruising around:

http://tamino.wordpress.com/2008/03/26/recent-climate-observations-compared-to-ipcc-projections/

http://rankexploits.com/musings/2008/what-would-it-take-to-disprove-global-warming/

Keiran wrote:

"Pity he left out 2.9 in April. But sun spots are just part of the solar picture".

2.9 was not the average of daily sunspot numbers for the month of April 2008. It was 5. But sunspot numbers vary all over the place.

Chapman wrote that the solar cycle bottomed out over a year ago, and Karoly pointed out that this is not true. If you average the numbers monthly, the minimum was last fall, just as Karoly stated.

There are lots of ways to average sunspots in order to smooth out the radical daily variations. To come up with the standard smoothed numbers, they are always 6 months behind. So knowing the sunspot numbers through the end of April, you can calculate the smoothed sunspot number for last October.

The monthly numbers jump all over the place, but if you figure a 3-month moving average, the trends are easier to spot, and don't take as long to look at results as the standard 12-month number.

Here is a 3-month moving average including all daily sunspot data for 2007-08:

Jan 07 22.7
Feb 07 18.5
Mar 07 11.2
Apr 07 12.2
May 07 15.8
Jun 07 18.7
Jul 07 15.4
Aug 07 10.2
Sep 07 5.4
Oct 07 3
Nov 07 6.9
Dec 07 8.1
Jan 08 8.5
Feb 08 8.4
Mar 08 8.4

This shows a minimum last October, precisely what Karoly said. The March 08 number is the center of the 3-month average, so it includes all daily numbers for February 1 thru April 30.

Keiran complains that climatologists leave out "other essential solar pulses", a term I am completely unfamiliar with. Can Keiran refer to a peer-reviewed scientific paper on astrophysics that defines this term, or even uses it? Just what does it mean?

He mentions aa index, but that is a measure of the earth’s geomagnetic stability, never cited by skeptics of global warming as driving climate. Besides, study after study by climatologists shows no link between sunspots (which are much cooler than surrounding ares) and climate.

Oh my goodness Hamster. Are you saying you haven't heard of the solar wind, or coronal holes or coronal mass ejections or M and X class flares or propagation or background x-ray flux or electron fluence etc, etc. Perhaps I should direct you to some appropriate material to read up on but that may be too easy.

Yes you say ... "aa index, but that is a measure of the earth’s geomagnetic stability" is correct and our earth has a strong internal magnetic field. However, does it occur to you that the solar wind is able to modify this field, creating a cavity called the magnetosphere? What do you think this cavity does to the surface of the earth? Do you know that it is filled with plasma much of which originates from sunnyboy? Would this influence climate, perhaps?

When you say "Besides, study after study by climatologists shows no link between sunspots (which are much cooler than surrounding ares) and climate.", well all i can say is keep looking but don't overlook the full solar/cosmic picture. Incidentally, what is your understanding of the cause of the Maunder Minimum?

Col. To cut a long story short, 1 we have nowhere to go if something goes wrong. 2 In the mean time, population reduction and technology advancements with more space research wont go astray.
The three hundred years (give or take) I spoke about, is the time it will take for a new type of atmosphere and climate, which will probably be like something the dinosaurs or the mammoths enjoyed. Look at it like a pendulum on a clock.
The carm times the world has enjoyed has come to an end and now its swinging backwards and forwards. Hot or dry then cold or wet. My guesstimating is, in time that pendulum will stop on one or the other.

I don't think there's any need to worry at the moment excepted for the fact that as time goes on, feeding 6 billion people with this climate unpredictability happenings, cause its raising its ugly head now with people starving to death and its going to get worst.

This pendulum theory is just a visual of what Iam seeing around the world and we are not preparing, seeing or doing anything about it.
True, it wont come to an extinction, but on the subject of, in the last 100 years, it has been the fastest extinction rate in recorded history, and that alone, must be ring some alarm bells.

I believe in the next 50 years, the human race is going to learn a very hard lesson.

Keiran>"but there are others here taking their lead from wicked pedia propaganda."

Because 153 citations in the wikipedia article i linked to does tend to destroy the average idiots credibility. My how wicked.