We could argue for long time about “trends.” The data from 1998 to 2007 do not constitute a “trend” in the sense that you could fit a line, but there is a net cooling from 1998 to 2007, driven largely by the 1998 outlier. My point was that this is beside the point.

To make verification of the IPCC projections meaningful we would have to pick a timescale and a variable or set of variables. I would suggest we would need to select at least a decadal time scale (e.g. 10-year averages using an agreed-upon smoothing function). Besides averaging out interannual modes in the climate system (NAO, El Nino, PDO) the other reason for looking at decadal-or-greater timescales is to get a time interval over which we can see significant accumulation in GHGs in the atmosphere. We would need to pick timescale on which the airborne fraction of GHGs increases at something close to the sensitivity of the models to their radiative forcing.

1997-2006 trend is .40 to .58 when you move back 1 year.
1996-2005 trend is .35 to .58 when you move back 2 years.
1997-2007 trend is .40 to .58 when you add 1 year.
1996-2007 trend is .35 to .60 when you add 2 years.

So our minium on the trend line is “getting warmer” going to 1998-2007 when you shift the 10 years or add years. Yes, when you add 2 years the maximum does “get cooler” but not as much as the minimum “go warmer”.

How is “cooling trend” defined? What do you compare the anomaly trend of 1998-2007 to and saying it’s cooling?

Are you saying because the 10 year period was .16 it is cooling compared to the 12 year period of .25? That seems to make no sense. Or shifting the 10 year period backwards giving a rising minimum making it .16 compared to a shift of 2 years at .23? That seems to make no sense either, when the min is lower and the max the same of course the number is bigger for the range.

I would think the different between the bottom and top of the trend line is not the way to look at it, perhaps the different between the two.

Compared to the 12 years 1996-2007 the 10 years 1998-1997’s trend min was .07 higher and max was .02 lower. This gives an overall rise of .05 from the 10 year period compared to the 12, yes?

I am not sure if that is the correct way to see if 1998-2007 is getting cooler or warmer or staying the same. We have to know what to compare it to, don’t we?

Oh! 10 years mean min/max is .5 and 12 years .475

Many participants in the scientific debate over AGW have become “advocates” for or against particular policy steps (e.g. Kyoto Protocol). Some of the “politicization” arises from the failure to distinguish between the scientific questions, and the issue of what, if anything, to “do” about them.

In my view (and I think this is what Roger is getting at with many of his posts at this site) the philosophical pitfall comes from the presumption that settling the science questions makes some policy step (or its avoidance) inevitable.

Some people labor under the implicit premise that if only policymakers and society at large could be convinced that global warming is real and due to human action, carbon-limitiations schemes like Kyoto would be implemented (leaving aside the question of the efficacy of Kyoto). Not necessarily – climate science is not the only (and indeed may not be the most important) factor driving energy and carbon-emissions policy. But the premise makes any challenge to the *science* a threat to the policy stance that GHG emissions must be cut.

Similarly, many opponents of limitations on fossil fuel emissions seem intent on discrediting the science of global warming as a way of forestalling action. But there are other, perhaps more immediate reasons to cut our carbon emissions with more certain science behind them. Examples include local and regional pollution which pose a public health risk.

So the “science equals policy” presumption shifts the battleground over this area of policy from politics, economics, sociology, and engineering to climate science.

The 1998 to ~2007 global cooling trend does not, in itself, invalidate the longer-term multi-decadal trends at issue in the AGW discussion. But some advocates for Kyoto-style emissions-limitations set themselves up for an argument over year-to-year trends by citing 1998 as the warmest year of the 1990s decade and citing that warmth as support for the policies they advocated.

That might be the reason.

Here is how I responded on his blog (my second try):

“Joe are you not letting my response through? This is my second try after seeing the first deleted (by accident?).

Wow Joe, this is a cheap smear even by your standards.

You could have emailed me to ask about the quote or any of the other
allegations that you make about me in this post. But you did not.

My views have remained consistent for many years, and here is how I
summarized them before Congress in 2006:

http://sciencepolicy.colorado.edu/admin/publication_files/resource-2466-2006.09.pdf

It is possible to believe that we need to act on climate change
(mitigation and adaptation), while at the same time having little
faith in the ability of climate models to make skillful predictions on
the time scales that that action needs to take place. It is also
possible to support mitigation while realizing that adaptation is also
of critical importance.

And I’m not the only person who thinks a little air needs to be let of
of the climate prediction bubble, compare a leading climate modeler,
Tim Palmer of the UK-based European Centre for Medium-Range Weather
Forecasts who says “Politicians seem to think that the science is a
done deal, I don’t want to undermine the IPCC, but the forecasts,
especially for regional climate change, are immensely uncertain.”
http://environment.newscientist.com/article/mg19826543.700-poor-forecasting-undermines-climate-debate.html?DCMP=ILC-hmts&nsref=news7_head_mg19826543.700

Will you be slandering Tim Palmer here as well? Other scientists have
expressed similar concerns.

Your intolerance of different points of view is simply stunning. Your
twisting of words and statement to smear speaks loudly for itself.”

http://climateprogress.org/2008/05/21/the-strange-case-of-dr-pielke-and-mr-hidebound-on-reaching-1000-ppm/

In point #7 he states:

“That when all of this involves risks of possible severe global economic and ecological disruption – in the future – it’s exceedingly prudent to do as much as is ‘feasible’, NOW, to avoid such risks, even if it looks a bit expensive and discomforting – and just might turn out to be ‘unnecessary’!”

Implementing the Precautionary Principle in the past has usually done more harm than good, making the action self-contradictory. It is ultimately based on a linear world view were straight lines are drawn from actions to consequences and from solutions to costs. The given risk is always the worst case scenario, while the cost of the solution is always assumed to be minimal. Invariably, reality never follows those straight lines and decisions based on them turn out to be worse than if no action was taken. The Precautionary Principle is neither precautionary nor a principle, but a noble sounding excuse for engaging in social engineering and generating ‘bad’ policy.

In Mr. Ornstein’s statement, the risk is depicted as “…possible severe global economic and ecological disruption…” So far, the only indication of severe global economic and ecological disruption from climate change exists in the computer models. There is no evidence in the real world that points to inevitable disaster, or even serious problems. To the contrary, the lack of warming in the past decade makes the worst case scenarios look ridicules, and calls into question the minimal predictions of warming derived from the models.

Mr. Ornstein’s presents the cost of the solution as “…a bit expensive and discomforting…” The reality is that the cost of mitigating CO2 emissions has already proven to be more than a bit discomforting, with unintended consequences causing some people to go hungry. These initial mitigation efforts would have to be much more severe to have any discernable impact on climate, making any potential ‘solution’ extremely expensive and disruptive (fancy talk for poverty and premature death), all for something that Mr. Ornstein readily admits …”may be unnecessary”.

It is more rational to rewrite point #7 as follows: “When all of this involves speculative and unsubstantiated risks of global economic and environmental disruption of some unknown quantity; and, while the proposed solutions have already demonstrated higher costs, unintended negative consequences and absolutely no indication of effectiveness, it is extremely unwise to pursue this course of action any longer.”

When both the climate system and human history are decidedly non-linear, what wisdom is there in drawing linear trends 100 years into the future, proclaiming predictive skill and implementing punitive laws based on that prediction? The wisest course of action would be to deal with known and well quantified ecological and economical problems that exist today, making future generations much more capable, resilient and adaptive to any ecological problems that we can not foresee, yet may come about in the future. That is what our predecessors did for us. It is what we owe to future generations.

But see how sly this is.
“I’m going to go out on a limb here and predict that the remarkable warming of the last couple of months won’t continue at the same pace over the next two months.”
At the time that was .13 and .41 up. Not difficult to say it will not be to 1.21 when May comes in is it?