By Joe Lynam
Business reporter, BBC News, Farnborough Airshow
Dark suits and summer airshows do not mix
The air conditioning died at about 1500 on Tuesday.
Even senior aviation bosses, with their bespoke suits and six- and seven-figure salaries, had to fan themselves with press releases while clutching tepid glasses of Diet Coke.
At 35 degrees Celsius, every air cooling device at the show had been turned up to 11 and had caused the power generators to crash.
In fact, the world's largest air show at Farnborough is something of a microcosm for the dilemmas facing the aviation industry as it tries to balance the needs of its customers: cost, comfort, efficiency and, increasingly, being "green".
And when it comes to the environment, sustainability is a key word.
Yet hardly anything as large and expensive as Farnborough has a shorter life span than this aviation city, which is created every two years in Hampshire only to be demolished a week later.
The show is a gathering of the great and the good from all over the world, whose sole purpose is to sell more planes, choppers and ancillary aerospace kit to governments and airlines.
It used to be easier when cost and quality were the key attributes in any sale. Nowadays, though, fuel efficiency and emissions are as important as air speed and the "bottom line".
That's why Boeing's biggest boast about its new 787 Dreamliner is that it is more fuel-efficient than its rivals. Airbus has a similar claim about its new A380 superjumbo, which was showing off at this year's Farnborough.
Both planes are proof that the aviation industry has been forced to react to the green lobby, which has been targeting the air travel sector as the one of the most damaging sources of CO2 emissions and poor fuel economy.
In fact, many conscientious eco-aware groups even refuse to travel to conferences to discuss the issue, since the very fact of flying there would be detrimental to the environment.
Concorde was hardly the most eco-friendly airliner
In a way, they have a point. One of the world's most emblematic and revered aircraft - Concorde - burned up 94 tonnes of fuel getting from London to New York and a whopping two tonnes simply taxiing onto the runway.
And it's not just when the planes are in the air.
Airport terminals are the source of some toxic gases and by-products, such as the de-icer used on frosted planes in the winter.
Not forgetting the controversial noise pollution issue, which has troubled residents and planners for decades.
But the aviation industry is desperately trying to dispel what it sees as some of the myths that environmentalists have been putting about.
The International Air Transport Association (IATA) admitted that air travel accounted for 2% of global CO2 emissions, but also 8% of all economic activity.
"Even if all air travel stopped," according to Giovani Bisignani, chief executive of IATA, "the result is only a 2% global improvement in CO2 emissions. But the impact on global economies would be disastrous."
In other words, ground all planes and the last thing on your mind will be the environment.
So the dilemma facing governments and regulators is: how do you foster economic growth (i.e. trade) and at the same time reduce the amount of pollutant gases being created by the very air travel which makes the economy tick?
Most suggest the solution is in the design of new aircraft. Design has created about 1% more fuel efficiency every year for the past 20 years and the hope is that this figure could rise to between 1 and 2% over the coming decade.
Boeing's Dreamliner is touted as a greener plane
The problem is the continuing rise in air travel and the resulting jump in CO2 emissions: on average, between 3 and 4% a year.
So even if planes are better designed, it would only be chasing a moving target in terms of fuel efficiency.
Some groups believe the answer is to levy some sort of air congestion charge. The Aviation Environment Federation proposes a green air travel tax of 3.6p ($0.07) per passenger for every kilometre flown.
That would make a trip from London to Tokyo (9,536 miles or 15,346km) £552.45 or $994.42 more expensive for travellers.
That's unlikely ever to fly with passengers or politicians alike.
France has already introduced an air travel tax of one euro per flight. But that money is intended for developmental aid rather than combating any environmental issues.
With the aviation industry booming at the moment - as in evidence here at Farnborough - something radically new might be needed to square the circle of making the aircraft of the future without costing the Earth.