It’s perhaps a little counter-intuitive to mark the opening day of the Copenhagen summit with observations about air travel. But I have a persistent bugbear.

It is the completely ludicrous and almost uniquely British action in forcing passengers to extract their liquids from their hand baggage and put them in plastic bags – which then have to be inspected separately – clogging the security checks.

I have blogged before on the matter and reminded people that the first liquid bomb aboard a plane was attempted over Indonesia as long ago as 1995. In the decades after, no action was taken affecting passengers carrying liquids. Since then we have had convictions in UK anti-terror trials for a plot to attempt much the same.

Having flown of late from Sao Paolo to London, Geneva, and Copenhagen itself. I can report that none of the non-UK airports I travelled through had the remotest interest in my liquids – so long as I wasn’t flying with a British airline. Indeed to my dismay, I find I mistakenly failed to drink a tiny bottle of Pomagne, kindly donated by a BA steward en route to Geneva. So here it is in my baggage upon arrival on another flight to Copenhagen.

The matter of liquids has been rubbished time and again in European Parliament debates. But the issue has now descended to farce. Not least because it is perfectly possible for people to fly on planes into the UK with as many non-plastic-bagged uninspected liquids as they like.

Hence departing UK passengers and users of British owned airlines are being discriminated against, both in terms of security clearance time lost and in having to do it all.

What’s it all about? Is it an attempt to sustain a level of anti-terror hysteria to justify the incredible expenditure on the “war on terror”, or has someone forgotten to check whether anyone else is still doing it? Small thing I agree, but…

And while I am on it, is Terminal 4 at Heathrow the terminal God and BAA forgot? Having done it up well since BA left for the world’s best airport facility – Terminal 5 – BAA seem to have abandoned any idea that passengers might need to transit through it, as I did from Brazil on Saturday.

To reach Terminal 5, as many must to connect to domestic or European BA flights, you are advised to take the train (13 minute wait when I got down there), or try the bus.

There is now no longer a terminal-hopping bus – maybe that’s one up to climate change? Instead there are 27 bus stops and at only one, bus stop two, is there any sign as to which bus actually goes to Terminal 5.

Just one stop, the other end of the concourse. The buses are all red – Transport for London popping in from Richmond, or some such. The wait here was 11 minutes for a ride that stopped at obscure rustic retreats around the airfield before making it to Terminal 5.

Total time of transfer between two terminals in one airport: 26 minutes. Is this a record? And what did the excellent Brazilian Airline TAM do wrong to have their passengers treated in this way?