The Marmite maker said the labels would appear on up to 30,000 goods by the end of the year, giving consumers a front-row view of the planetary cost of their purchasing habits.
The announcement followed news that insurers are considering replacing stolen or written-off petrol and diesel cars with electric vehicles.
Irreparable gas boilers could also be replaced with greener alternatives, and it could become the norm for replacement parts to be remanufactured, rather than new.
These measures are examples of a recent paradigm shift which has positioned environmental, social and governance issues at the heart of the corporate agenda.
Go green, or risk red balance sheet
With investors recognising the financial benefits of green investments, environmental capitalism is growing.
For many consumers, however, environmental considerations remain either an unaffordable luxury or an area of resolute apathy.
Will the corporate world's laser focus on green issues thus create a gulf between producers and users? Or will reluctant consumers acknowledge the inexorable direction of travel and adapt their behaviours?
Companies unquestionably exert huge influence over consumers and the way they buy and use products, said Andrew Schein, a lead researcher at the Behavioural Insights Team. He cites this power dynamic as the “foundation” for building a more green-minded society.
He welcomes the idea that companies are thinking deeply about how to make their products and services sustainable.
He is also happy that consumers are starting to take responsibility for the power of their day-to-day actions.”
However, Mr Schein's optimism is not unalloyed and he pointed out that companies are not uniformly using their influence for the environmental good.
“Companies could make it a lot easier for customers to engage with products sustainably, and engage with the circular economy,” he said.
“I feel like companies don't do enough right now to make it easy for customers to make the right choice.”
It would certainly take a most starry-eyed corporate acolyte to suggest corporations are a uniformly benign influence, but it is in the fact they have such an influence in the first place that Mr Schein sees cause for hope. The more green companies become, the more green consumers will inevitably become.
This transition will not necessarily be a rapid one, especially if companies limit themselves to “information-based interventions” like the Unilever carbon footprint scheme.
“Expectations should be fairly low,” said Mr Schein of the initiative.
“It's asking an awful lot of the consumer to make a different choice about which product they're buying based on labels.”
He gave the example of the limited impact of calorie labels on food packaging.
“Here you have an incentive that's directly tied to the person's self interest: their health.
“[With carbon labels] we're talking about something that's for the social good, less directly tied to a person's self interest.”
Mr Schein isn't dismissive of Unilever's carbon footprint labels, however.
“Why not publish the information consumers deserve to know, and insofar as it might change consumers' behaviour, that's great.
If information-based interventions represent the more persuasive approach to turning consumers green, then vehicle insurers replacing write-offs with an electric car by default represents something more akin to direct action.
“Defaults are very powerful and I can see this scheme having a major impact,” said Mr Schein.
Being forced behind the wheel of an electric car lies somewhat at odds with the notion of choice baked into modern-day consumerism. Mr Schein doesn't believe this presents a problem, rather just a way of normalising greener choices.
He is more concerned about the practice of greenwashing: when a company misleads its customers into thinking its products are more sustainable than alternatives.
His fear is that “customers might become hopeless about their ability to discern what products are 'truly' sustainable, and in the process lose motivation to adopt sustainable behaviours.”
Again, it boils down to influence. If companies can change consumer behaviours for the better, then they can certainly change them for the worse too. Fast fashion anyone?
But even if corporate motivations for proselytising a greener agenda are not purely planetary, from the perspective of a behavioural expert like Mr Schein, it is the outcome that matters most.