Analysis tools for 65-year climate in MATLAB and Excel
Vaughan Pratt
Stanford University

The data and software tools in this directory are for producing the following graph (click on it to enlarge it). This shows residual climate after detrending HadCRUT4 since 1854 by 1.7*log2(CO2) and (1 - 0.3)*TSI/4 (the blue curve), and the result of filtering the residual with a 65-year moving average filter (the red curve). The implication is that all climate impacts not removable with such a filter can be accounted for to within a few millikelvin in terms solely of the Sun and CO2. The Sun has a 107-year cycle that a 65-year filter attenuates by close to 0.5 and therefore would remain quite visible if not removed, while CO2 has been on an exponentially increasing rise since the start of the industrial era that is barely touched by the filter.

The three-line MATLAB script that plotted this graph is clim65.m. You also need all the data, which is contained in the script load_Period_HadCRUT4_CO2_TSI.m, along with the moving-average function ma.m. (In some other systems, e.g. R, ma is part of the library, but strangely not in MATLAB.)

Just those three files is all you should need: put them in the same folder and run clim65 from the command window. If you encounter any difficulties feel free to email me at my surname (all lower case) at cs.stanford.edu.

Caveat: TSI is based on NOAA's reconstruction. Stanford's Leif Svalgaard has challenged its accuracy and has proposed an alternative reconstruction. If you use it instead of NOAA's TSI data you must increase CO2 climate sensitivity from 1.7 to 1.87 degrees per doubling of CO2, and solar sensitivity from 1.0 to 1.83 degrees per W/m2 of top-of-atmosphere TSI in order to demonstrate the removal of all climate impacts save CO2 and Sun with a 65-year filter. This might motivate non-luke-warmers to take a look at Svalgaard's reasons for preferring his reconstruction.

The Excel spreadsheet is here. It assumes recent versions Excel for safety since older versions were more vulnerable to viruses in spreadsheets you might run across on the web. If there's interest I could save a version that works with Excel'97 but you'd want to be sure it was from me and not a copy someone's been playing with.