The Blackboard

The current status of the falsification of the IPCC AR4 projection of 2 C/century is: Falsified. I first discussed this falsification in IPCC Projections Overpredict Recent Warming. That discussion included some caveats. I have been addressing criticisms as they arise. Today, I am addressing a discussion by Tamino, who decided to reanalyze the existing [...]

Winter brings hunger:
The furry frisky squirrels
get me to feed them.

One day, this little squirrel discovered that peanuts rain down from my open window. She also noticed that the window is opened when my favorite squirrel, Rumpy, visits. So, now, whenever Rumpy is in the yard, she stops by too.
Here’s Rumpy. [...]

There seems to be some confusing about just which IPCC projections were falsified. In particular Tamino is misinformed. This misunderstanding is likely due to lack of clarity on my part. So, I’d like to clarify: It’s the AR4 predictions that are falsified by recent data — not the TAR.
So, criticism that, somehow, [...]

Recently, I have been interested in the answer to these questions:
How does the IPCC really make projections? When were tuning parameters in models used to create projections in the TAR “frozen”?
Both questions were motivated by one of the many of the puzzling features of a recent paper by “The Rahmstorf Six Seven”, often [...]

Recently, the subject of using only one set of measurements to perform a hypothesis test arose. As many are aware, I prefer to average over instruments. But, I’m willing to consider each set individually. So, today I did that.
My main results are: Looking at the data 12 possible ways, I get 9 results [...]

I thought I’d fiddle with my spread sheet and create a graphic I’ll be able to easily update month to month. This way, when the temperature trends flip to positive as predicted we’ll see that. Later, if and when the trend begins to increase to the level predicted by the IPCC projects, we’ll see [...]

Several readers have requested I comment on Rahmstorf et al. 2007, which compares the TAR predictions to data. Rahmstorf is a brief one page paper, which provides a visual comparison between HadCrut measurements of the global mean surface temperature and IPCC projections.
Can anyone tell me precisely which figure in the TAR matches Rahmstorf’s temperature [...]

    
The first day of spring:
Opossum waddles slowly
across my backyard.
    
We get a lot of opossums around here. I don’t see them much during the winter. Heck, they are nocturnal, so I don’t often see them out in the bright sun. But, cutey was out there wandering around 10 am. I wish he’d turned [...]

ATMOZ’ recently posted an interesting analysis that explains why one must always be aware of the properties of weather when doing statistics. I agree with that. I would go further. I would say one must always be aware of the properties of any underlying phenomena when doing statistics.
More specifically, ATMOZ suggested that maybe [...]

William Connolley seems to be having a little trouble understanding how one can apply statistics to a set consisting of a time series with many data pairs, and then state a range for climate trends that are consistent with the noisy data.
As it happens it’s easy using standard statistical techniques applied to data [...]