mrtravel wrote:
> James Robinson wrote:
>>
>> whitely525@yahoo.co.uk wrote:
>>
>>> @panix.com (Randy Hudson) wrote:
>>>
>>>> Nelson wrote:
>>>>
>>>>> Aircraft leave vapour trails which aid in the reflection of
>>>>> the sun's radiation back into space.
>>>>
>>>> A study of the no-fly period following 9/11 showed a full extra
>>>> degree (Celsius) of cooling over the US during those four days,
>>>
>>> I think you mean warming..! According to the theory it is masking
>>> global wamring.
>>
>> On the contrary. The theory is that while the creation of cirrus
>> clouds will reflect sunlight during the day, the presence of the
>> clouds will also trap heat overnight. The net effect of both is
>> supposed to increase temperatures by something like 0.1 degrees C, at
>> least according to a NASA report, which seems to be conservative.
>>
> But that isn't what this report said. It said the temperature
> deviation, during the air travel restrictions during the days after
> 9-11 were one degree more than normal and this was due to the increase
> in the high temperatures.
That report was simply a comment on the effect following 9/11, and it
confirmed that contrails tended to dampen the diurnal temperature change.
I posted the link as it responded to the earlier poster's comments on
average temperature change.
The data gained from the shutdown following 9/11 have allowed climate
forecasters to calibrate their models of global climate in the absence of
contrails. The general conclusion is that contrails contribute to global
warming. That conclusion is not universally held, and there is much
debate on whether the change is significant enough to be worried about.
You are always free to post your own links to appropriate discussions. |