Global Warming - us, or <sinister background music> something else?

[steveb64]

I think that somewhere in this thread I asked for some justification for the idea that undersea volcanic CO2 emissions are (or might be) greater than (or comparable with) human CO2 emissions. A few posts back Mr Merde posted a link to a paper from a PNAS colloqium that talks about big changes in ocean carbon chemistry on century time scales near Bermuda, and much else besides. But it didn't talk about whether it was feasible for volcanoes to have produced a significant proportion of the rise in CO2 for the last few centuries or decades. (I mean, you'd think you'd notice something.) Damned interesting paper though, I'd lile to get hold of the full text.

However I did find the following on

http://volcanoes.usgs.gov/Hazards/Wh...as/volgas.html



So where are all these volcanoes?

This illustrates my point. In science, if you have an idea, an hypothesis, you have to write it down, consider its consequences (where might these volcanoes be, how would they change the ocean chemistry around them). Then you go out and test your ideas about the consequences (predictions) and see if they hold up. If your aim is just to obfuscate and confuse you just throw out vague ideas and by the time people have realised they're rubbish you've moved onto the next one. Meanwhile the old idea (which might have been discredited, or so vaguely described it can't be discredited) lives on like a zombie in the half-world of blog forums.

But re the underersea-volcano idea, I'm not ruling it out, I'd lust like more information on how it might work.

It's a nice day out there!

Yep. Warm...

And then there's the GHG's being released from the melting permafrost...
Quote - "A frozen peat bog covering the entire sub-Arctic area of Western Siberia, the size of France and Germany, contains billions of tonnes of greenhouse gas that is melting for the first time since since it was sequestered more than 11,000 years ago before the end of the last ice age."

Link: http://www.terranature.org/methaneSiberia.htm

...and this interesting article...
Link: http://www.countercurrents.org/cc-081005.htm - and if you're thinking - Nah, the ice couldn't melt that fast... There's the fact that >3200 sq kms of ~200 metre thick iceshelf (Larsen B) broke up and floated away in 35 days a few years back...
Link: http://nsidc.org/iceshelves/larsenb2002/

...and the acceleration of melting of the Greenland icesheet... Link: http://www.finfacts.com/irelandbusin...10006908.shtml

And then there's the fact that the IPCC appear to be underestimating things a bit... "The world's recent carbon dioxide emissions are growing more rapidly than even the worst-case climate scenario used by the Intergovernmental Panel on Climate Change, say researchers.

The team, led by Michael Raupach of the Australian Commonwealth Scientific and Industrial Research Organisation, looked at the growth of CO2 emissions and found that emissions growth suddenly accelerated in 2000. During the 1990s, emissions grew by 1.1% per year on average, but the number shot up to 3.3% between 2000 and 2004, when the study ended."
Link: http://environment.newscientist.com/...scenarios.html


Personally, I think it's too late to try and stop global warming - if any of you have studied airconditioning theory (yeah - got to study some odd stuff when I was a NZPO (Telecom) Tech) there's a thing called thermal inertia. Like regular inertia, it means that it takes a sustained input to get things (like temperature) changing - and then once they DO begin to change, if you stop the input, the change doesn't stop immediately. An example of this is summer/winter... ever notice how the warmest part of summer is AFTER the longest day... and conversely for winter... colder after the winter solstice?

Me - I'm more interested in preparing for the climate change, rather than in trying to prevent it. Sure, I'm also trying to reduce my impact on the planet as well - but I'm not a fanatic about it. Still drive a 4x4 - just try to use it as little as possible (more due to fuel price than anything else), use hi-efficiency lights (replaced them years ago, as the old style bulbs died) in the house, and have been (well, the wife has - mine tend to die) been busy planting trees - for food, shelterbelts, and firewood...

After having been through a 1-in-250 year flood (end of March), a 1-in-200 year storm (mid June - and the worst I've ever been in), and a 1-in-100 year flood (a week later!) this year - I'm still battening the hatches down!

Then there's being able to sit outside, at Turangi in the evening, in mid August, in our T-shirts! And I'm warm blooded....

[Jantar]

... You can't estimate average trends because you only measure temperature twice a day? Rubbish.

Perhaps you need to do a basic statistical methods refresher course. A linear trend when applied to a cyclical variable is meaningless. Yes, it can be done, but no significance can be attached to the resultant.

So the warming not's real because the surface temperature measurements are too sparse? What about glacier retreat, satellite measurements of tropospheric temperature, boreholes, changes in growing seasons?

Some warming is real, some isn't. Warming in urban areas is certainly happening due to UHI. But if we consider your other evidence Glacial retreat is occuring in some places, but Glacial advance is happening in others. Sattelite data shows that we are now in a cooling cycle. Boreholes show that warming has occured since the MIA, but most warming occured in the first half of the 20th century.

90,000 measurements of CO2 were suppressed? That's because they were taken in cities, near vegetation, where the concentration is affected by local sources. And some of them used bad techniques. This was sorted out with great difficulty in the 1950s by Callendar and Keeling. Ernst-Georg Beck and Vincent Gray seemed to have missed that.

So you consider it OK to take temperature data from cities, but not CO2 data? So is it still OK to blame temperature on CO2?

The models haven't been tested? Computer models in the 1980s did a good job of predicting global warming over the next 15 years.

The absence of any global warming for the past 8 years? Look at the data!

The data shows that temperatures have fallen since 1998. I have posted the link to the actual data on here many times, and shall do so again when I am back on my own computer.

[Jantar]

...Increasing the concentrations of the GHGs will increase the amount of absorbtion of outgoing radiation in the respective wavelengths. Information I have seen suggests the concentrations of these GHGs is increasing, so I would expect more absorbtion of the long wave radiation...

Quite correct, but the relationship is a logarithmic one. That is it requires 10 times as much CO2 to a achive a doubling of the CO2 contribution to warming.

Its a bit like painting a window with black paint. The first coat stops 90% of the light getting through. The second coat stops 90% of whats left, so now only 1% gets through. A third coat will stop virtually all the remaining light. putting on further coats does nothing. With Green house gasses the earth is usually in a state that further increases will not make any significant difference.

[Badjelly]

Is this thread still going? Just a couple of responses

So you consider it OK to take temperature data from cities, but not CO2 data?

Well they are different quantities with completely different spatial distributions. CO2 is uniform through the troposphere, except near big sources and sinks (eg plants, industrial sources in cities). To characterise CO2 trends all you need is some stations in isolated areas, a few in each hemisphere (Mauna Loa, Baring Head, South Pole). Temperature varies diurnally, annually, with height, according to surface type, so you have to measure it in more places to get a global mean. Still, if you want an estimate of global average temperature over the last few decades, why not try this:

http://en.wikipedia.org/wiki/Image:S...mperatures.png

This shows surface temperatures and satellite estimates of tropospheric temperatures. They differ in detail and the trends aren't exactly the same, but they're pretty similar don't you think?

The data shows that temperatures have fallen since 1998.

To me, the graph I linked to above shows a rising trend with a few troughs and spikes, including a big spike in 1998. To you it shows cooling since 1998. Oh well.