Climate change...

[Roxy the Rat Girl]

The Carbon price in Europe has slumped to $3.34 Au per Tonne. Ouch, that's not what Labor wanted to hear!

http://www.abc.net.au/news/2013-04-17/european-carbon-price-slumps-after-french-plan-fails/4634344

[therisingblues]

Hey there Psyber,
Been a bit busy of late, so haven't had too much of a chance to fully explore those links. I still don't think nature is a major contributor though. Through the sources you've recommended and my own searches, I believe even stronger that humans are greater contributors.
Eg. Milankovich cycles: where's this spike you've mentioned over and over? I've only found experts testifying to the opposite of what you said, ie. according to Milankovich science and temperature records corresponding to the cycles, we should be entering a cooling phase! That this isn't happening has caused scientists to search for alternative causes.
Eg.2 A massive contributor to CO2 levels in the past: volcanoes emit tiny amounts of CO2s compared to humans in the modern age. The champion of the "volcano theory" Dr Plimer, refuses to do interviews when there's a volcanologist present. On top of that he's the owner of some mining companies. I imagine global warming is a real pisser if you own a mining company eh? Better make up a story to the contrary, never mind if you're a geologist treading in climatology turf, just the fact that you're a scientist carries weight for at least a couple of interviews, until it becomes apparent that everything you've said was made up!
Everything I've read so far by every properly credentialed expert suggests nature's contribution to climate change is minor compared to human's. The only people who disagree are not experts in the appropriate fields and usually have vested interests in an industry that'll suffer through carbon taxes and the like, ie Dr Plimer and his mining companies.

[Psyber]

Hi TRB, if you look through the Wikipedia chart of the Milankovitch cycles tracing the CO2 line (blue) you will see the highest CO2 level on that chart at approximately 325,000 years ago. ( It appears to have been close to 300ppm.) The red temperature line suggested we were at or just past a peak there, but it was oscillating.

However, as I said here some time ago, I've learned since some of my early posts that those levels are not right up to date, and that present CO2 levels are now above that old peak. I've had no problem accepting that the further rise is human contribution, after I spoke to an expert at the University (John Tibby) who put me onto an article showing how to relate old ice core samples to current flask air samples. (There I just wanted to be sure we were comparing apples with apples, and, once I was, I posted here saying so.)

I was at a presentation at Adelaide Uni, recently, where the speaker had a real time CO2 level analyser running live.
Air drawn from outside the Horace Lamb lecture theatre door to the Uni grounds showed 380ppm.
The level in the enclosed lecture theatre quickly rose to IIRC about 718ppm.

I'd love to be able to borrow the analyser for a day to see whether the CO2 levels up here in the hills are as high as in to Uni grounds, or whether all those vehicles and Adelaide's disputed inversion layer inflates the levels in the CBD.

Milankovitch Cycles.jpg (109.16 KiB) Viewed 161 times

[Psyber]

This longer term chart of polar ocean temperatures is interesting too though it does not closely relate to our immediate problem.

65 million years temps.jpg (31.18 KiB) Viewed 159 times