"We can't put all our energy in one barrel," says the BP billboard poster. The slogan is accompanied by fetching images of green plants, wind turbines and the sun. And BP's own logo, with its green tagline: Beyond Petroleum.

But this is confection. Until 2004, BP was called British Petroleum. And in the real world of business, the giant energy company continues to plunder most of its profits from - and sink the great bulk of its investment into - barrels of oil. Who is it kidding?

Well us, it hopes. You may have seen another of its posters. "There's energy security in energy diversity," it says. "BP provides oil, natural gas, wind, biofuels, solar and options." Or, reading its recent print adverts, you may have puzzled at what it means by the headline "Hydrocarbons and low carbons living in harmony."

Let's get real. BP likes to say that it is investing $1.5bn (£980,000) a year in "alternative energy". True, I am sure. But that word "alternative" is clever. Delve a little further and it turns out that BP's alternative energy division includes not just wind and solar and biofuels but also natural gas-fired power stations. Natural gas may be less polluting than coal and oil, but at the end of the day it's a fossil fuel filling the atmosphere with CO2. Alternative? Not by my definition.

Also sheltering in the alternative energy division is BP's "emissions assets business", which makes money out of carbon trading, and a venture capital unit. But even if we lump all this "alternative" activity together, it still only makes up 7% of the company's planned $21bn (£13.85bn) investment this year. The remaining 93% is oil, spiced up with some coal.

Now if BP were new kids on the alternative scene, we might regard 7% as good progress. But the sad thing is that BP was making waves in renewables a decade and more ago. Back then, it was a pioneer among oil companies. In 1997, the year the Kyoto protocol was agreed, environmentalists applauded the green initiatives of then-chief executive Sir John Browne. For a while they looked like deeds rather than just words. Soon, Sir John was Lord Browne. But some of BP's investors got cold feet. Browne was ousted and the oilmen returned to centre stage.

Take one example of the difference this has made. Back in 1999, Browne pulled BP out of its involvement with developing Canadian tar sands – an energy-intensive process with a carbon footprint several times that of conventional oil. Last year, BP bought its way back into Canadian tar sands.

The current bout of BP greenwash is especially questionable for its British customers and shareholders. Earlier this month, BP pulled out of wind power in Britain. And, after years justifying its continued involvement in coal by extolling the potential for capturing and burying carbon dioxide emissions from coal-fired powers, it withdrew from a British government competition to come up with a viable technology.

Yes, BP is continuing with a clean-coal project in Australia; and yes, it is investing in wind power in the US, in anticipation of a renewables push from president-elect, Barack Obama. But this niche activity is small fry for a company that just announced profits for just three months of $10bn (£6.59bn). BP claimed that those profits paid for investment in alternative forms of energy. Maybe. But those 13 weeks' profits also exceeded its anticipated investment in renewables for the next six years.

Is this a company that has stopped putting most of its investment "in one barrel"? Is this a company seriously trying to create a world "beyond petroleum"? Sadly it is not. Worst of all, it is a company that appears to be retreating from deeds to words.

• How many more green scams, cons and generous slices of wishful thinking are out there? Please send your examples of greenwash to greenwash@theguardian.com or add your comments below