[Neil S. Briscoe]

Neil S. Briscoe  asked the Naked Scientists:
   
Hi

Just listened to your last Sunday's broadcast and heard at the end that you're talking about planes' vapour (or con) trails as cloud formers.

Some time ago, I heard on one of the World Service's broadcasts that, thanks to the 9/11 attacks (when they grounded all flights) people were able to work out that con trails during daylight hours were actually an assistance to prohibiting global warming whereas con trails during the hours of darkness were an aggrovator of same.

I hope you are going to be able to confirm, or otherwise, what I've previously heard.

Many thanks.

Regards
Neil

What do you think?

[LeeE]

First of all, think you need to shift your thinking from the idea/concept of 'global warming' to that of global climate change, for while some regions may get warmer others will almost certainly get a lot colder, and the very important bottom line is that no one knows what will actually happen.

Having said that, I do recall hearing about research that seemed to reveal that the absence of jet aircraft contrails was noticeable.  However, that is not to say that the absence or presence of jet contrails makes any significant difference to the global climate; it is just just that the difference was detectable.

The bottom line, I suspect, is that when compared with the natural variation in cloud cover due to the much larger scale 'normal' weather systems, the presence or absence of jet aircraft contrails is likely to be negligible because even though they may act as 'seeds' for areas of cloud formation larger than just that of the contrail itself, these will still be tiny in comparison to the already extant weather formations.

[yor_on]

I can assure you that we will have a global warming no matter how many aircrafts we put up When white, some of the sunlight do get reflected by the ice crystals inside the clouds but when dark ) forget it, well not really there's still ice reflecting but the clouds will magazine more heat the darker they become. It's called Albedo

"Different types of clouds have different albedo values, theoretically ranging from a minimum of near 0 to a maximum approaching 0.8. 'On any given day, about half of Earth is covered by clouds, which reflect more sunlight than land and water. Clouds keep Earth cool by reflecting sunlight, but they can also serve as blankets to trap warmth.'"

Furthermore, the aircraft will accumulate to more CO2 as it burn up its fuel exchanging it for thrust. And that fuel comes from under the earth adding to the pollution we have. But I do love aircrafts So let's take care of the cars first, shall we?

[thedoc]

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