Tuesday, March 09, 2010

Global Warming: How not to do an article

We skeptics always hold the AGW-crowd to high standards in publishing article. We even nitpick on their references, if they are bad (e.g. “Grey literature”). However, I think, if one nitpicks, then one has to prove that you are better. Now, this here is a very good introduction into the problems skeptics have with modern AGW assumptions. It is a very enlightening blog post, but a bad article of science.

It easily explains what our problem with AGW theory is and where we concur with realclimate-climatists. However, if one reads the comments carefully, one can also concur with the criticism. There are several points that are just assumed but not referenced. Here are just some examples:

  • greenhouse gasses keep the Earth 30°C warmer than it would otherwise be [Reference missing]
  • Forcing-equation is different than in traditional literature (5,35 * ln(C/C_0) = Forcing – Myhre98)
  • CO2 is about 10% of all greenhouse gas warming [reference missing] – I thought this was a bit low
  • Plant growth shuts down at 150 ppm [citation missing]
  • why should positive feedback effects be assumed as a linear gain [citation?!]
  • Red bars are not really “anthropogenic” – it’s a misnomer – it’s actually positive feedback due to higher average mean temperatures due to CO2

A point of notice here to skeptics: Higher average mean temperatures are more important than daily temperatures or even yearly temperatures. There can be yearly average temperatures that are higher than the mean average temperature due to CO2 but they won’t necessarily start the positive feedback run. It is important to tell people that this is on big time scales, not years but probably more along decades (at least as such I understood it). This still doesn’t make up for the “positive feedback in a natural system is NORMAL” mistake, but it explains why mean average surface temperatures ARE important over longer time scales, rather than smallish data points of a year that only show exceptional warm weather, but not climate trends (because the positive feedback has a time delay, if I understand correctly and thus needs several years of higher temperatures to actually get going).

Nonetheless, the post is good for a first glimpse at the problem, however, it should not be viewed as scientific article!

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