By 16 September this year, the area covered by Arctic ice had shrunk to 1.6 million square miles. The ice always contracts over the summer - but not this much: the previous low was 2.05 million square miles, recorded in 2005. Earlier in the year, the Intergovernmental Panel on Climate Change reported that sea levels are rising at 20 times the average rate over the past 3,000 years. In the history books of the future, 2007 will be recorded as the year that the threat posed by climate change became irrefutable, imminent and catastrophic. The question is whether 2008 will be written up as the year we did something about it.
At the moment, fewer than one in 20 of us have made significant changes in our lives to reduce our environmental impact. The fossil- fuelled juggernaut of the hyper-mobile consumerist economy has barely touched its brakes. At an individual level, many of us salve our consciences by recycling our newspapers and buying Ecover washing-up liquid, while continuing to drive to the airport for our flights to continental Europe and beyond.
At a political level, the prime minister (when he was chancellor) could declare 'a new ambition for Britain... to lead the world in creating a stable and sustainable economy founded on low carbon - a Britain that is both pro-growth and pro-green'. But then the Government can build new runways and widen motorways without even the appearance of any cognitive dissonance. Since Labour came to power in 1997, the cost of motoring has fallen by 6%, while train fares have jumped by 7% and bus fares by 16%.
If individuals and governments are failing, can businesses do any better? British firms exhale 66 million tonnes of carbon a year - but of this, almost a third is wasted through poor building design and energy inefficiencies. It has become important to many firms to demonstrate their green credentials - not only to customers but also to employees. (They have to tread carefully, though: a dozen companies were recently rapped by the Advertising Standards Agency for misleading environmental claims.)
But companies are becoming alert to the rise of 'ethical employees' who want their employers to be greener. A recent survey by Badenoch & Clark, the professional services recruiter, found that 41% of employees say that they would be more likely to accept a job offer from a firm with strong green credentials, and that half felt that their current employer did not take environmental issues seriously. It seems likely that in the near future, some firms might become toxic employer brands, in the same way that tobacco companies are today: examples might include fossil-fuel-reliant energy utility firms, oil and gas companies, and airlines.
It's difficult, though, for even the most diligent workers to know what being environmentally responsible amounts to. Declaring carbon neutrality has become a badge of pride: but many of the offsetting schemes used to achieve neutrality are of dubious quality and efficacy. One of the most common forms of offsetting is planting trees, but only fully grown trees absorb much carbon, and trees take a lot longer to grow than a 747 takes to fly to New York. Similarly, a company might invest in brightly coloured recycling bins but fail to switch to a green electricity supplier.
There's a great deal companies can do to make their buildings more energy-efficient, much of which would save them money, from wholesale switching to natural cooling systems and solar panels to fitting a £15 timer on a soft drinks machine to turn it off at night and weekends - which saves about £160 on the annual electricity bill.
But the biggest impact an employer can make is through changes in the culture of working. Even firms that claim to be carbon-neutral start the carbon clock only when an employee walks through the door: their journey to work does not feature. But in the UK, the average employee commutes 46 minutes a day - and seven out of 10 do so in a car. Many of the most impressive green offices are in out-of-town locations, easily accessible only by private car. If companies are serious, they should include employee commuting in their overall carbon foot- print, and work to dramatically reduce it. There are generous tax breaks for companies that encourage greener commuting, but take-up is dismally low, and the 'company car' has failed to become the anachronism it needs to be. Being able to work from home must become the norm.
Similarly, reliance on air travel must be dramatically reduced. In many firms, the number of zeroes on a frequent-flyer programme card is a symbol of status; but allowing staff to benefit in this way from environmentally damaging forms of travel is simply immoral. How can firms that hold meetings in locations that require everyone to fly justify this, if not to themselves, then to their children? Mea culpa - I speak at a number of conferences, and have often flown. But that is often the only way to get there.
The truth is that all conference organisers know that a warmer location is often one of the key attractions: Barbados catches the attention in a way Birmingham does not. But we all have to stop. So here's a deal. There are 100,000 readers of this magazine. If one hundred of you pledge not to fly for the next year - just let me know at the e-mail address below - so will I.
Richard Reeves is director of Intelligence Agency, an ideas consultancy; e-mail: firstname.lastname@example.org.