[JR: No. They project that linearity through at least 2020 (and 2030 in the RealClimate figure) in order to make their claim that there will be no substantial warming over the next decade.]

That these are real is not in any doubt in the world of oceanography, hydrology or fisheries biology. The exclusion of climate jumps in 1976 and 1998 is a deliberate exclusion of natural climate shifts from the underlying CO2 trend.

The residual trend is calculated in the same way as the 0.2 degrees/decade increase calculted by the IPCC – except with different end points. The 0.1 degree/decade trend in Swanson and Tsonis is simply the trend on an interval that excludes 1976 and 1998. Points that are not arbitrary but based on an understanding of multidecadal climate shifts that are not random and are evident everywhere in the climate record.

Despite Swansons understandable prevarication – the climate sensitivity for a 0.1 degree trend would seem to be less than the sensitivity represented by a 0.2 degree trend.

There are 2 possibilities – the 20 to 30 year climate shifts are caused by an internal dynamic process. In which case there is no loss of heat from the ocean/atmosphere system – it simply redistributes. From the ocean to the atmosphere in a warm phase and from the atmosphere to the ocean in cool phases. Much as heat is transferred from the ocean in an El Niño and to the ocean in La Niña.

The other possibility is that it is caused by something (like clouds) that changes the actual radiative balance of the planet.

I would definitely opt for clouds at this point – both low and high cloud in the climatically importent equatorial zone declined to 1998 and have increased since. The change in shortwave forcing calculated by the guys at Project Earthshine is -2W/m2 since 1998 – climatically significant.

Neither ocean or atmosphere temperatures are trending anywhere currently. I have done the calculation for the enthalpy of fusion based on recent mass increases in the oceans – and it is not nearly sufficient to account for the missing heat that should, according to the theory, be there.

To have a look at your assumptions that the global warming hiatus requires believing 1) something very unusual happened in the past decade and 2) global warming is linear.

The claim is that these ‘unusual’ events happened around 1910, the mid 1940’s, the mid 1970’s and 2001/2002. It is not unusual at all and is very evident in fisheries, hydrologic and oceanographic science.

I believe that what is being claimed is climate episodes of 20 to 30 year duration. This is far from a claim that climate is linear. You have had a quick look at the graph and jumped to wrong conclusions. I am sure it is not your fault – you just need a broader education. If the climate shifts are not evident statistically – and I believe they are – then look at the physical science.

Swanson and Tsonis talk about natural variability – and you speak about random variation. There is nothing random in climate – only processes we don’t understand. The difference is that Swanson and Tsonis understand a little better the physical environment.

Statistics suggest that a cool mode of the PDO is associated with less intense and frequent El Niño and more frequent and intense La Niña. A change over a couple of decades in the frequency of ENSO. This is just one element of multidecadal climate shifts – but it suggests that you shouldn’t hold your breath waiting for a big El Niño to turn things around.

[JR: I've offered a bet that says otherwise. No takers so far.]

Measuring the global warming by looking at air temperature is like weighing your dog by putting his tail on a postage scale, and then estimating your dog’s total weight from number on the scale. Any number you get for your dog’s total weight is not going to be very accurate. So, we apply statistics to the numbers and argue about them. (My dog’s tail is stronger than your dog’s!)

“The Earth has been cooling since ????” completely ignores the heat that went into melting a lot of Arctic Sea ice. Swanson does not address ice. Just because the heat is not in the air does not mean that the Earth has not warmed. Melting ice is ongoing global warming even if the air temperature does not change.

Somebody will say that it is more heat than can be accounted for with a bit of sea ice. If you look, I think you will find that we are also missing a bit of permafrost, some ice shelves, glaciers, and some anchor ice.

Moreover, ice events remind us that global warming is not linear.

I’m not personally convinced of the Swanson paper (it’s in contrast to most other estimates) but I believe it to be a serious effort done in good faith.

You can truncate, manipulate and otherwise torture the data to support a forgone a conclusion, but it doesn’t make it valid.

Bottom line: if you cite something or use it as a basis for a conclusion, you can’t ignore the part you don’t like or that doesn’t support your bias.

And dhogaza, I don’t know what your point(s) is (are) but that’s what Swanson’s done. Period.

http://www.washingtonpost.com/ wp-dyn/ content/ article/ 2009/ 07/ 13/ AR2009071302852.html

True, in a long term way like say, the replacement of dinosaurs with mammals (and similar shifts in the plant kingdom). But the term “mass extinction” isn’t just made up. It refers to real events – “severe perturbations” if you will. So sure, eventually both the plant and animal kingdoms will recover from whatever max CO2 humans impose. The number of humans (and what sort(s) of civilization) that survive 1000 ppm CO2, … well, that’s not so guaranteed.