The Blackboard:

How many of you think the measurements of GMST are imprecise? As in, they might contain errors of some sort? I do.
Nevertheless, up to now, I have been performing hypothesis tests applying the assumption that the time series data for global mean surface temperature (GMST) are AR(1) distributed. I have [...]

Trends for the Global Means Surface temperature for five groups (GISS, HadCrut, NOAA/NCDC, UAH/MSU and RSS.) were calculated from Jan 2001-June 2008 using Ordinary Least Squares (OLS) using the method in Lee & Lund. to compute error bars, and Cochrane-Orcutt and compared to the IPCC AR4’s projected central tendency of 2C/century for the trend [...]

Evidently, the APS (American Physical Society) is inviting papers to debate a very specific conclusion of the IPCC:
There is a considerable presence within the scientific community of people who do not agree with the IPCC conclusion that anthropogenic CO2 emissions are very probably likely to be primarily responsible for the global warming that has [...]

Sometimes, a picture is worth a thousand words.
See the blue vertical line at 2 C/century? That’s the central tendency for trends projected by the IPCC in the AR4.
See the bell-shaped curve? That’s a spread of trends due to “weather noise” that we might expect if the “weather noise” is similar to that [...]

If I understand Gavin in comment correctly, he is requesting that I expand the features I consider to be included in the IPCC projections to include more information. The idea is that, by including features describing the variability of weather over time, the current trend could be found to fall into the range for weather. [...]

Answering comments yesterday, I posted a graphical representation of IPCC projections for the 21st century. This is taken from the AR4:

It occurred to me that some readers might notice that, in the image, the projected line matches the hind-cast temperature at 2000. So, they might be interested in seeing how data might compare to [...]

Some of you may rush to your computer this morning and noticed that Gavin posted to let us know he found a “neat” way to ENSO correct data. Amazingly to any American, he did this at 7 pm, July 4th. If you are an avid reader of “The Blackboard”, [...]

A number of us have been debating whether the agreement between Hansen et al 1988 predictions/projections and later data is good, bad or indifferent. Naturally, the assessment depends a bit on the extent to which the applied forcings used in the projections match the data.
Some confusion has arisen regarding [...]

After Hansen’s 20 year anniversary talk last week, I read some comments debating the question, Is it warmer than June ‘88?. It appears different people understand the question differently, and so give different answers both at other blogs and in comments on my previous post.
During the course of the conversation, various other questions were [...]

Trends for the Global Means Surface temperature for five groups (GISS, HadCrut, NOAA/NCDC, UAH/MSU and RSS.) were calculated from Jan 2001-May 2008 using Ordinary Least Squares (OLS) using the method in Lee & Lund. to compute error bars, and Cochrane-Orcutt and compared to the IPCC AR4’s projected central tendency of 2C/century for the trend [...]