New Tree Ring Study Ignores The Effect Of CO2
By Paul Homewood
Andrew Montford has a post up on the latest tree-ring based temperature reconstruction of summer temperatures in the northern hemisphere. It attempts to show that current temperatures are unprecedented in the last millennium.
Steve McIntyre is already poring over the statistics, but there is one issue raised by several commenters. That is the question of what effect increased levels of CO2 in the atmosphere have had on the tree rings.
It is well established that CO2 has a significant effect on plant growth, and accepted that tree ring studies can be skewed as a result.
It was therefore astonishing to find this comment from one of the study’s authors, the UEA’s Tim Osborn, on Bishop Hill:
5. CO2 fertilisation effects.
We don’t identify or remove such effects. The empirical evidence for sustained effects (i.e. over decades) on trees in cool, moist locations over long periods of time is scarce.
Jan 14, 2016 at 5:36 PM
This one comment tells us so much about the lack of integrity in climate science nowadays. Just because there is a lack of empirical evidence does not mean the whole issue can be trundled off onto the sidelines.
Now maybe CO2 will make little or no difference. But if it cannot be properly accounted for, the whole study (or at least the 20th part of it) becomes worthless. Indeed it simply confirms what we already knew, the fact that the climate went very cold in the 19thC, and that since then temperatures have somewhat recovered.
There are 23 authors listed for the study, all I gather tree ring experts. Surely one should have had the integrity to stand up and point out the elephant in the room?
We often talk about the corruption of money in climate science, but I sense another factor in play here. This is the belief that they are all doing something so wonderfully important.
When saving the planet is the objective, why let a few inconvenient facts get in the way?