Pope Benedict XVI recently called for a Permanent World Wide Car Boycott (http://melbourne.indymedia.org/news/2007/04/144209.php) We need the same for air travel.

I am puzzled by some assertions in this article - aviation currently expends 2% of our greenhouse emissions. This is likely to increase by 250% by 2050, that is equivalent to 5% of our present greenhouse emissions. We need to cut back to 20% of our present emissions by 2050. And thus aviation emissions will equal our total allowance by then? 5% greater than 20%? Perhaps I have made a mistake in calculation or reading of the article, though I have double checked.

I am becoming increasingly sceptical of the figures often glibly cited by advocates of particular positions, for or against various actions.

Related issues of ‘peak oil’ and humanity’s dependence on fossil fuels are worthy threads, constructive comments help.

BigMal obviously does not understand the concept of ‘positive feedback loops’ in terms of climate science (no matter his highschool/academic background) so I will try to explain (I apologise to others who know already).

Water vapour and CO2 are powerful greenhouse gases absorbing long-wave radiation. Water vapour concentration increases as a result of a global warming and enhances the greenhouse effect further (positive feedback loop). The rate of evaporation is affected by the temperature and higher temperatures increase the (saturated) vapour pressure.

One important difference between water vapour and other greenhouse gases such as CO2 is that the moisture spends only a short time in the atmosphere (say 10 days) before being precipitated out, whereas the life time of CO2 in the atmosphere is in the order of a 100 years.

Consequently, the planet will experience more extreme weather events (floods and droughts); some areas will benefit, other areas will not.

There is plenty of evidence that the oceans and terrestrial biosphere are not absorbing the amount of carbon we have been releasing into the atmosphere.

BigMal, can you point me to your claims “they can still tell us with absolute confidence that in 100 years time we will all be frying in hell”. If not, are you not scaremongering like some politicians?

On a more sober note, for those that haven’t studied the science on global warming and want to understand the concepts and make constructive comment, the following site is worth a look at;

http://www.realclimate.org/index.php/archives/category/extras/faq/

And bigmal, if you don’t understand the science, ask the moderators/contributors questions, you won’t be limited to 350 words, you might learn something.

Or this;

http://ipcc-wg1.ucar.edu/wg1/wg1-report.html

this is the AR4 report that caused all the fuss in the 1st place and the reason why governments, businesses, individuals and groups are taking climate change seriously, unlike some people with their head in the sand and living in the dark ages.

The real world has moved on bigmal, the debate is what to do about GW

Personaly, I don't believe for a second this rubbish of Global warming.
From my seat, all I can see is another opportunity to rip us off some more bigtime.
I do believe we have created "LOCAL" weather changes due to our own stupidity and greed by indiscrimanently clearing vegetation willy nilly and the idiotic spread of suburbia.
Now, getting down to the emissions from aircraft, it's very strange that these facts are not published more widely, especially when we are being told GW is a serious threat, another strange anomaly is the emissions from military vehicles, and in that frame, I include, Land/Sea/Air, which are some of the worst offenders you can imagine, not to mention the effects of their explosives used so indiscrimantly.
One mode of transport that comes to mind, is sea transport, recently visited a web site in the U.S. where it was alledged super tankers emit up to 15 tons of sulfur per hour whilst under power, similar ships also emitt massive emissions whilst under transit,(Hmmm, maybe this is the reason we are seeing so many DEAD areas in our oceans these days ?) hand in glove with ships are diesel railways, these are also huge contributors of emissions to our environment. Let me tell you, one gallon of diesel will not even start your average Loco, nor will a 200 litre drum of the same stuff.Worse still, operators in an effort to keep their costs as low as they can, buy the cheapest diesel they can lay their hands on, and this is mostly of very inferior quality which they'd never get away with, trying to use it on road transport.
Yet in all the discussions/hype/gab fests, NONE of these mode of transport are ever mentioned nor given consideration.
Thus, I come away with the belief, the messengers of doom regards GB are liars and spreading fear under false pretences.

Well done Davsab. You took the bait.

I have had a look at the IPCC reports, and Real Climate web site and all that they prove is that we dont really know.... still, and whats more the IPCC is saying this as well, once you get beyond the corrupted SPM document.

The debate is certainly not over. The Head of NASA ( Griffin) is more correct than your mindless attempt at a rebuttal

The relationship between C02 and temperature is still logarithmic, the amount of outgoing infra red at the TOA is still normal.

The MWP was still hotter than today by at least 1C, and the troposphere still isnt behaving itself,and the River Tornio in Finland, with records going back to 1690, has still performed the way it always has, showing that we were getting warmer long before power stations and motor cars.

The Antarctic is still getting bigger, and colder.

The GCM's still cant model clouds properly and the IPCC documents themselves say this. There is as much uncertainty about the albedo effect measured in w/m2 as there is Co2 effect. Roger Pielkes critique of the IPCC report you referenced,and the way GCM's are put together and used just confirms ones suspicions about their efficacy.

Droughts in the USA are now being show to be lessened by the effects of GW, not increased. It just goes on and on.

Oh, and BTW, the story that Co2 stays in the atmosphere for 100 years is based around the isotope ratios and uses a calculations/techniques that are now seen to be flimsy.

Have another try.

I am sure all the world’s political, business and religious leaders would be pleased to see BigMal’s published and peer reviewed theories on GW in the appropriate journals.

They may want to take into account his musings before adopting or implementing strategies that would have world wide repercussions!

On the other hand, could it be that BigMal just likes fishing and playing games on forums such as OLO?

Avagoodnight