CO2 levels over the millennia.

But when you add the period since the beginning of the industrial revolution...

(note the horizontal axis on each of these graphs is opposite. Mine has the recent past at the right and Tony's has it at the left)

Fancy a punt on what will happen over the next hundred years?
Perhaps all cats should be removed from cars til we work out what to do.

Tony

Probably better to remove the drivers than the cats ...

Cats from cars?

Really, really difficult to be accurate, but I don't see it switching back any time soon. There seem to be a lot of factors pushing in one direction; increasing human-caused GHG emissions as the majority of the world's population catch up with us on their specific emission levels, lower reflectance of diminishing ice, melting of subterranean and sub-ocean methane hydrates and release of the entrapped methane as the north warms, drought and deforestation due to climate (adding to human-caused clearing). Things pushing in the other direction are increasing particulate and aerosol pollution, increased energy efficiency, higher plant growth rates in some areas and some currently trivial replacement of fossil fuels with non-carbon sources. FAR too little, too late.

If I was a betting man, and I'm not, I'd lay money on a tipping point being reached soon, and a long-lasting and devastating shift in the earth's climate that will likely reduce the carrying capacity to fractions of a percent of our current population. But that's just me (and the utterly overwhelming major proportion of the world's climate scientists).

I suppose my points are that the climate might well change by just as much anyway, and most of us feel absolutely helpless.

Tony

quote:

Originally posted by Tony Lockhart:
I suppose my points are that the climate might well change by just as much anyway, and most of us feel absolutely helpless.

Tony

I swing between "helpless" and "responsible". My one ray of hope is in the area of geo-engineering. Quasi plausible suggestions of adding aerosols and particulates to the upper atmosphere to shield the earth and cool things down. In effect an artificial volcano. Technically it may be feasible, but politically a non-starter, I fear.

It will also be interesting to see how the planet manages the changes itself.
In some ways I think we are being selfish. What do we matter? If every land based mammal and all birds died tomorrow, very quickly we would be replaced, the Earth would just carry on.
Ignore me. I'm EXTREMELY tired.

Tony

Basically the earth warms and cools for any number of factors way beyond our control such as dispersion of the molten core towards the crust followed by shrinkback. changes in axis tilt with magnetic fiels reversals, the behaviour of the Sun.

On the time scales in Tony's graph we have had global warming and ice ages. They will keep on happening regardless of our puny efforts.

I am not advocating irresponsibility and resourece management is to be recommended. (Try telling the Chinese though)

But the CO2 generated by the microbiological cycle is massive compared to what we add.

Roll on Nuclear Fusion as an energy solution that could REALLY help.

regards
Geoff

quote:

Originally posted by Geoff P:


But the CO2 generated by the microbiological cycle is massive compared to what we add.



regards
Geoff

No doubt, but it is the NET shift in CO2 that matters. The point about the natural cycle is that it is (was?) in equilibrium. Yes, that equilibrium point varies as a result of a number of factors, but one systematic and very significant disruption to it is man-made CO2 emissions. The science of this is beyond doubt. Don't dismiss it, simply because the predictions and scientists are not perfect.

However-when you view the levels of Carbon Dioxide over Geological Times the current levels are very low!!!
Also-the graph that Winkyincanada attached is the now discredited and infamous IPCC hockey stick curve which smoothed out all variations in climate pre-industrial revolution.

Steve

quote:

Originally posted by steveb:


However-when you view the levels of Carbon Dioxide over Geological Times the current levels are very low!!!
Also-the graph that Winkyincanada attached is the now discredited and infamous IPCC hockey stick curve which smoothed out all variations in climate pre-industrial revolution.

Steve

I just added the recent data to Tony's graph. The common data between them is pretty close. I've heard about this medieval warm period etc. The denialists are clutching at straws. The science is in.

Yes, over the 100's of million year timeframe, the CO2 has come down as bio-geological process very gradually fixed this CO2 into oil, gas, coal etc. The issue is that we are now releasing a portion of it back into the atmosphere over a vanishingly small period in comparison. Life cannot adapt at that rate. There will be catastrophe.

quote:

Originally posted by winkyincanada:


But when you add the period since the beginning of the industrial revolution...

(note the horizontal axis on each of these graphs is opposite. Mine has the recent past at the right and Tony's has it at the left)

Ah, the infamous "Hockey Stick" graph. Note that the vertical axis is not rooted at zero. This graph has been pretty thoroughly debunked in my opinion. (reminder to self "must go and check which axis is X and which Y" - one of my blind spots)

Please explain to me why the current "global warming" is also happening on the outer planets? Could it possibly be due to changes in the heat output of the sun.

To me the biggest argument against CO2 being a primary driver is the largest reservoir of CO2 is the oceans. What happens to gases in solution when the temperature goes up? The gases come out of solution. So, if you blame us, then surely we should be in a massive positive feedback loop?

Anyway - to all the hypocrites here. If you're really concerned, you should forget all about optimal performance of your Naim equipment, and start switching your gear OFF when not using it.

quote:

I've heard about this medieval warm period etc. The denialists are clutching at straws. The science is in.

Not sure what your implication is here-the medieval warming period is fact as is the little ice age-not an invention of denialists whoever they are- the evidence exists for these events-especially from the isotope evidence from the Greenland Ice Sheet- the fact that the IPCC erased them form their graph is a serious concern-if you are sure of your facts why manipulate the data, in fact the graph shape could be generated from any random data, the IPCC withdrew the graph and have since restored the medieval warming period and little ice age to the graphs. Despite the rise in carbon dioxide we are still at lower levels of temperature than over last 10,000 yrs, whatever you think was the warmest year- from most data it is 1934-then over 9000+ yrs were warmer despite far lower levels of carbon dioxide suggesting that there are far more factors involved in climate change- I am no denialist or sceptic rather an Earth Scientist who despairs at the simplistic view that the sole driver of climate change is carbon dioxide. Climates change and have always done so and will continue to do so-all we are basing this on is a statistic-10 or 20 yrs of data averaged.


Steve

Fully agree it is not simple.

I'm amazed that we actually think we can do anything to change this round like the politicians will have us think so they can keep ripping us of even more.

quote:

Originally posted by winkyincanada:
Glaciers...

I looked at this link and on the bottom of the page, left, another link made me forget all about global warming disputes.

Thanks for that.

Questions:

what is the current level of CO2?
what is the anthropgenic level of CO2 in the current level?
where does the non-anthropgenic CO2 come from?
what level of CO2 is acceptable i.e "safe"?