By Tim Weber
Business editor, BBC News website, Davos
Climate change was last year's big topic in Davos
In 2007 climate change was the big topic at the World Economic Forum. One year on, is big business acting green?
Environmental campaigners call it greenwash - when a company, organisation or government makes grand claims about its environmental record, but has little evidence to back them up.
Is Davos any different?
The environment had largely disappeared from the forum's agenda. A few sessions examined, for example, whether biofuels are really beneficial, whether carbon trading works, and why nuclear energy is back in fashion.
Last year's hot topic had become a casualty of the forum's habit of trying to push new issues on to the global agenda.
But the reality is more complex then that.
'Unified earth theory'
Can we have both development and environment?
It may not say "green" on the tin, but environmental issues popped up in many other guises.
Whether developing countries can be lifted out of poverty without accelerating climate change, was discussed by poverty campaigner Bono and former US vice president Al Gore, who recently received a Nobel prize for his fight against climate change - an issue that was raised in session after session.
Japan's Prime Minister Yasuo Fukuda for his part announced in Davos a $10bn, five-year package to help developing countries tackle climate change without risking growth.
Water scarcity was another environmental topic big on the agenda, and companies like Nestle and PepsiCo were pushing their green credentials by explaining their efforts to help cut water consumption.
Michael White, chief executive of PepsiCo International, reeled off a long list of projects where his company was sharply cutting back its water usage.
"In India we have reduced water usage by 40%," he told me, and all of PepsiCo's factories had been ordered to meet tough water efficiency targets and "help local communities to save water as well".
Carbon rating your holiday
William McDonough runs a firm of architects that is redesigning Google's headquarters: "When I spoke to the meeting of the chemicals and construction industry here about sustainable building methods, they were really very open to the idea."
Travel is a major contributor to climate change
Indeed, there is hardly any company that is not eager to show that it tries to help the world go green in its particular sector.
"When we talk about the environment, it's not window dressing," insists Jeff Clarke, chief executive of Travelport, one of the world's largest travel conglomerates.
The company runs travel reservation systems such as Galileo, and consumer travel websites such as Orbitz.
A year ago at Davos, he says, he became convinced that his company had to contribute to fighting climate change, not least because the $1 trillion travel industry is "a major contributor to global warming".
Travelport is a data-driven company, updating 4.3 billion fares every day.
Mr Clarke's solution: customers booking a flight should be told more than the ticket price and the type of plane used on a route. Within a year Travelport hopes to give every single flight a carbon rating, taking into account the plane, the type of fuel used, and other data points.
"Some planes are three-times more polluting on the same route than others," says Mr Clarke. "It is inconceivable for me that in a decade from now the carbon rating of a hotel or plane is not part of the consideration when a customers is booking a trip."
Off the hype curve
Are industry's green pledges just greenwash?
Environmental entrepreneur Shai Agassi says the lack of an official green agenda in Davos is actually a good sign.
"It just shows that we are off the hype curve and into solutions."
He points to his own company, Better. Together with Renault Nissan he hopes to persuade Israeli car drivers to switch from petrol to electric cars. New highly-efficient batteries combined with green energy from solar and wind power are supposed to end Israel's dependence on petrol imports by 2018 at the latest.
Mr Agassi has the backing of the government and large companies in Israel - and says that a string of other car firms and countries have also expressed an interest.
"Expect three to five similar announcements this year," he says, and predicts that "the minute we prove [our model] works, the whole market will tip" in favour of clean, electric cars.
That, however, is still very much in the future.
In Davos, endless rows of four-wheel drive cars were idling outside luxury hotels, waiting to ferry executives from meeting to meeting.
For some bosses, going green starts elsewhere.