According to this site about 2-3% of the global emissions. http://www.yaleclimateconnections.org/2015/09/evolving-clima...

Seems like something other than flying might be a better target to reduce carbon emissions.

I'm not sure if I trust the numbers, but it looks like airplanes produce about 1.5% of the total global "CO2 equivalent" GHG emissions.

https://www.epa.gov/ghgemissions/global-greenhouse-gas-emiss... says that transport is 14% of total global GHG emissions.

And http://www.atag.org/facts-and-figures.html says that airplanes are 12% of transport emissions.

I certainly don't trust the numbers. There is common sense right?

If we stick water vapour and co2 above the weather layer in the atmosphere, it will act like a pane of glass in a greenhouse? Right? You can't rain anything down from 35000ft can you?

Look at the warming graphs/animations, most warming happens in the northern hemisphere (where most planes fly), since about 1970, which is when air travel became popular accross the northern hemisphere.

Call me crazy (I know it's dangerous to make assertions without 150% of the facts) but that seems to me like an obvious thing that would affect warming. Please don't reply with some fact based rebuttal - hasn't helped so far.

So you don't trust the numbers? And you say don't reply with fact-based rebuttals? You seem to be saying that your opinion is fact-free. That's... not very persuasive to the rest of us.

I'm more likely to trust the numbers than someone who says "don't reply with facts". Yes, there is common sense; numbers can be misleading. But common sense can also be misleading; don't cling to it against all evidence.

All the numbers we have heard about causes, haven't altered the overall increase in the PPM co2 number. I don't trust that we won't discover more about this situation. My hunch is flying is one of the biggest feedback mechanisms, because of where it happens (high in the atmosphere), how it interacts with the ecosystem (contrails), and the sheer volume of fuel used daily (economic vested interests).

I see contrails every day above my head, they fill the sky on some days.

There is a problem with the sky, the coincidence seems striking to me.

Like smokers in the 1930's being prescribed cigarettes - common sense should be able to indicate a truth that is yet to properly emerge.

This should be some interesting reading for you if you haven't read it already: Some scientists believe that from the days after 9/11 (when everybody was grounded) that planes and their pollutants actually have a cooling effect on the planet; they reflect sunlight more into space.

[1]http://www.pbs.org/wgbh/nova/space/contrail-effect.html

I did read that at the time, and it is interesting. But as James Lovelock says - one of the first people to alert us about rising co2 - smoke or soot is the only countermeasure we have now, but it is a very short term fix and the other gases mixed with it lead to rapid longer term warming.

Water vapour from planes (contrails) have a complex effect and is not yet fully understood see:

http://www.smithsonianmag.com/science-nature/airplane-contra...