This post relates to a challenge posed by Gavin at Real Climate, to better depict the long term history of temperature. Gavin linked to datasets ranging from instrumental (150 years) to Phanærozoic (540 M yrs). I have been experimenting with user-adjustable graphs (see also gallery). The big changes of scale are a challenge, but I thought it was worth a try. The current version is rough, but I'll put in more data, with selectable axes.
The graph initially shows the last 200 years or so, but with a temperature scale big enough to cover the whole period. You can adjust the scales as follows:
- Translation - by mouse dragging in the plot space. However, zero time (before 2014) is fixed to the origin.
- Temp scale - by dragging vertically in the space to the left of the y-axis.
- Time scale - this is the critical one. You can make fine adjustments by dragging below the x-axis. But faster is to click in the region with <...>, blue, bottom left. < shrinks the scale (longer times), and the response is proportional to how far you click from the centre (about double per <).
|0-600 Mya||Veizer et al (2000), Royer et al (2004) (updated Royer (2014))||Veizer d180, Royer04 Temp, Royer14 CO2|
|0-65 Mya||Zachos et al (2008), Hansen et al (2010)||Zachos/Hansen|
|0-5.3 Mya||Lisiecki and Raymo (2005)||LR04 Stack|
|0-800 kya||EPICA Dome C||Temperature Reconstruction|
|0-125 kya||NGRIP/Antarctic analog?||NGRIP 50yr|
|0-12 kya||Marcott et al (2013)||MEA12 stack (xls)|
|0-2 kya||Mann et al (2008), Ljungqvist (2010)||MEA08 EIV, Ljungqvist10|
|1880-2013 CE||GISTEMP||GISTEMP LOTI|
|1850-2013 CE||HadCRUT4||HadCRUT4 Global annual average, Cowtan&Way (infilled)|
|1850-2013 CE||Berkeley Earth||Land+Ocean annual mean|
I have currently done HadCRUT4, GISTEMP LOTI, Ljungqvist10, Marcott et al (2013), EPICA Dome C,Lisiecki and Raymo (2005), Zachos and Hansen, Veizer d180. L&R is d190O data, so I scaled to to match Z&H over the first 5 million years. Veizer is ocean bottom temperature, so I used a faint color - I'm currently just trying to get the scaling to work well. So here is the plot:
Update: As Gavin at RC noted, I had L&R upside (d18O). Fixed now.
Other imperfectionsI haven't been careful with anomaly base - the data is as is. I tried adjusting sequentially by overlaps, but there is noise, and for the moment, I don't think it adds value.
I have smoothed and sampled opportunistically. Epica was smoothed by three boxcar filterings, length 5, and then sampling every fifth. Zachos was smoothed once and sampled every fifth. L&R was sampled. With smoothing, end regions were included unsmoothed.
I'll surely find more.