A friend commented on the clear skies over the weekend being improved by the lack of planes in the sky, I just laughed it off but has he got a point -

A recent research conducted by UK's Met Office has pointed out that vapour trails by jet aircraft can cause cloud formation, capable of blocking sunshine for over 20,000 square miles in Britain.

According to a report in the Telegraph, analysis of contrails from one large military aircraft circling over the North Sea showed the creation of a thin layer of cloud that, at its peak, covered an area of more than 20,000 square miles.

The Met Office research suggested that the collective impact of hundreds of vapour trails can cause a blanket of thin cloud, reducing sunshine for millions who live under busy flight paths.

Contrails, which are clouds of condensed water vapour and soot particles made by the exhaust of jet engines, sometimes disperse within minutes, but can also be present in the sky for many hours.

They can also act as a catalyst for the formation of further wispy cirrus cloud.

Globally, vapour trails are thought to cut sunshine levels by less than one per cent, but this figure could rise to 10 per cent in areas under busy air corridors, such as the south-east of England.

The Met Office analysis was based on observations of a single military Awacs aircraft circling over the North Sea on a sunny day earlier this year.

Researchers had expected high-level winds to disperse its contrails, but instead, they appeared to attract more clouds that continued to grow as they were blown southwards until eventually they formed a hazy high-level blanket of cirrus cloud across southeast England.

According to Jim Haywood, the Met Office's aerosol research manager who led the new study, "At its peak the resulting cirrus cloud covered an area of more than 20,000 square miles."

"Such clouds are normally short-lived but, depending on atmospheric conditions, they can last much longer," he added.

It is thought that low temperatures at high altitudes can cause ice crystals in the vapour to act as 'nuclei' for condensation of more water, resulting in more cloud.

Haywood said that aviation-induced cirrus clouds had both a cooling effect, because of sunlight reflected back into space, and a warming effect, because of trapped heat.

"Studies show that, overall, the warming effect is stronger so aviation-induced clouds are helping to warm the planet," he said

Source-ANI
SAV

It was the same after September 11th. After the grounded flights, the weather changed dramatically. Warmer during the day, cooler at night.

Of course, this time we have the ash cloud... But over the weekend, we had lovely clear skies, good weather, warm and sunny, although nights were near freezing.

I live on the gatwick flight path and so have really noticed the drop in noise .. it's so refreshing not to have to stop a conversation every few minutes.

However as i work for an export company, business has been hit as we can't get goods in or out .. it would certainly destroy the business if this was a long term issue.

So, in light of this yin-yang effect, i would like to propose flights over the uk monday to friday, 8am to 6pm, then they stop.

That way my business doesn't suffer and i can still have my nice relaxed evenings and weekends in the garden.

I realise this may not be convenient for those in differing time zones but it would certainly suit me.

Didge

I like that. Air transport should be taxed more because of the global warming effects. Combined they could give you quieter weekends. the only problem is that people invariably be leaving on their holidays on a Saturday and return the following week/s on a Sunday, so they can maximise their time away.

When APD in the UK goes up in November it will almost be cheaper to fly to Holland and connect to a long haul flight from there than fly from the UK to the same destination. I don't think that two flights rather than one will be better for the environment.

It does depend on how the how taxes are applied. It should be Europe wide. The airlines should pay a fuel duty rather than passengers paying duty which does not affect freight or private planes currently.