re: #137 Pythagoras

Seems like the video pretty much agree with the position I was advocating at the end of the last thread on the subject here. Whether the latest temperature trend is slightly down or slightly up isn’t important. In the zigzagging temperature trend, it’s another zig. It simply makes the long term trend look linear.

I take the “moderate skeptical” position – specifically that global warming is not accelerating and, thus, will not be a catastrophe. In defending that, I’d like to avoid tangential arguments so I chose some raw data sources that are, I hope, completely non-controversial. I have avoided any references to Wikipedia or other sources with concerns about their accuracy. These are just raw data.

Temperature:

[Link: vortex.nsstc.uah.edu…]

(There are other sources but this one uses NASA’s Aqua satellite which has on-board fuel to maintain a constant orbit. Thus, objections raised for other sources don’t apply. They all pretty much agree anyway, but I don’t want to let in any tangents.)

Sea Ice:

[Link: nsidc.org…]

[Link: www.ijis.iarc.uaf.edu…]

[Link: arctic-roos.org…]

[Link: ocean.dmi.dk…]

While these four (US, Japan, Norway & Denmark respectively) are distinct they are highly compatible – generally validating each other. Note that the first 3 define “sea ice extent” as the area where sea ice exceeds 15%; the last one uses 30% instead, so it’s extent is lower. Also, the download button on the second one is a treasure.

Sea level:

This is important but I haven’t found one yet that is unassailable. The numbers are so small that precision is an issue. The current rise is about an inch a decade and the low end of the 2007 IPCC projection is 7 more inches by the end of the century – so there isn’t a ton of disagreement here anyway. Still, I’d like to add a sea level data source to this list.

My argument is this – they all show linear trends. You want to predict the next few decades, just extend the straight lines. The people who claim we’re about to reach a tipping point need to make their case and they, most notably, have not. They make statements but they don’t make detailed, quantitative arguments. All the “feedback” mechanisms (reduced albedo from loss of sea ice, methane release from melting permafrost, etc.) are already happening, and yet the plots keep marching in a straight line. The urgent predictions are starting to get a bit long in the tooth and they simply have not come true.

Yes, it’s warming. Yes, CO2 matters (I don’t know how much). But the people who want to change our lives have not made the case for what they are advocating.

Is there any data on permafrost loss that you are aware of? I’m still in the mushy middle on this… believe that there is AGW but rate/extent I’m not so certain about.

Hopefully some of your points will be discussed.