With fat-cat bankers on both sides of the Atlantic about as popular as a sneeze in an elevator you might imagine they would be especially careful with their reputation in any aspect of what they do that does not involve losing billions. Maybe that is why HSBC last week ran, in this paper and others, an advert for "Half-price Green HSBC Plus". It's an online account basically. So the deal is you "save paper by receiving no paper statements, cheque book or paying-in book … and no paper marketing."

Reader Tom contacted me about this. He was curious to see the other incentives. "I suspect that the small saving of paper would be more than compensated by long-haul travel and greater car use, with preferential rates offered for 'worldwide travel insurance' and 'roadside breakdown assistance' in the same 'green' ad."

I suspect you may be right, Tom. HSBC's marketing people really can't have got the zeitgeist right when they sweet talk us greenies with the prospect of better flying and driving. They used to offer things like cheap green electricity and reduced subscriptions to the Ecologist magazine. Not now. But there's quite a lot that bankers don't seem to get right now.

Exploring the bank's website for more details, it feels like green blackmail. Sign up to the green account option and HSBC promises to "radically reduce the amount of paper we send you" – which, of course, is mostly unwanted mailshots anyway.

So we are being invited to sign up to green banking in order to persuade them not to send us marketing stuff that we never asked for in the first place. Dear green-minded bankers, if you think it will make a difference, why don't you just stop sending the junk mail? Period. Now.

The greenwash persists. Reading the online bumf, I discovered the promise that "for each account you switch, we will plant one virtual tree in our virtual forest." Sounds green, but what's a virtual forest? Is that anything like a real forest, or something in Second Life? Well, only a bit. Keep clicking and it transpires that "for every 20 virtual trees we promise to plant a real one."

One day. Because it turns out they have 400,000 "virtual trees" in stock already and the best they can say two years on is that "we are now working with Trees for Cities to prepare the planting." It would be good to hear news about that. Because 400,000 accounts is a lot to get on the back of promises to plant trees.

I can hear the complaints from HSBC over this blog now. Maybe I am being unfair. They have employed some proper environmentalists. They put some solar panels up at their London HQ. The HSBC Climate Partnership involves them investing the not inconsiderable sum of $100m in green groups such as WWF over five years. Though I wonder how such green deals will fare in the current financial climate.

In 2005 HSBC declared itself "carbon neutral", by which it meant it has reduced and offset its emissions from its direct business activities — not that its investment portfolio is carbon neutral.

So when you put your money into that green account, you will still be investing in logging in Borneo, palm oil projects in Indonesia and digging up tar sands in Canada. But hey, at least you won't have a paper chequebook.

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