From the earth to the sun and everything in between, proclaims a BP advertisement, touting the company's investments in wind and solar power and biofuels. "Greenwash", the environmental group Greenpeace replies scornfully. Labelling this misleading spin from a dirty industry, the group argues that 93 per cent of BP's investment still goes to oil and gas. On the face of it, this is fair enough. The vast majority of oil companies' profits come, not surprisingly, from petroleum, however much they claim to be "beyond" it.
And the burning of oil and gas is one of the main sources of carbon dioxide, the gas most responsible for global warming. Further worrying evidence came last week: the past decade was the warmest on record, according to the US national oceanic and atmospheric administration. Yet the world's largest traded oil company, ExxonMobil, has been linked for many years with campaigns to discredit climate change science.
These are not the only oil companies under attack. Greenpeace accused Shell of "greenwash" over an ad campaign the company ran on sustainable transport in The New York Times in June. But here the argument was not that the campaign itself was misleading; it was simply damned on the grounds that an oil company could not possibly be environmentally friendly. This should be a warning to the oil companies. They will never attract praise or even acceptance from environmental campaigners such as Greenpeace, which regard even 1 per cent of investments in oil as 1 per cent too much.
Such environmentalists do not understand the financial and shareholder constraints on oil companies. A chief executive or board of directors that tried suddenly to shift US$20 billion (Dh73.46bn) of annual investments into renewable energy would immediately be removed. Most oil majors now have modest alternative-energy divisions, but corporations are not charities, and they have legal responsibilities to their shareholders. Wind and solar power have a bright future, but the world still needs hydrocarbons and the companies that provide them.
Some are quite upfront about this. Jakob Thomasen, the chief executive of Maersk Oil, said in May: "We have chosen not to get involved in renewable or alternative energy, as it is not our core competency." Mr Thomasen is absolutely right. Oil companies are not set up to compete in most forms of renewable energy. They are not manufacturers, such as GE, one of the world's largest wind turbine makers, or China's Suntech, the biggest producer of solar panels.
But neither are they "energy companies", a concept that died with Enron. Providing electricity, a low-return, steady, usually heavily regulated business, is completely different from finding petroleum. To compete, oil companies would have to adopt a very different business model, and supplement their solar plants and wind farms with conventional power from gas and coal, hence undoing the "green" objective.
This is not to say they cannot make green investments. Their first job, of course, is to operate their oil and gas fields safely and responsibly, to avoid environmental damage and oil spills, and to stop the wasteful practice of flaring unwanted gas. In all these areas, they have made great strides over the past few decades. Modern petroleum operations, including discreet oil wells within the cities of Los Angeles and Rotterdam, one of the world's busiest ports, are unrecognisable from the forests of derricks and lakes of oil familiar from old photos of Texas, or from the former Soviet Union.
Their next task is to increase gas output. When burnt, gas releases very few pollutants other than carbon dioxide, and even here it is much cleaner than coal. Replacing coal with gas is one of the fastest, cheapest and easiest ways to cut carbon emissions. Beyond this is the emerging technology of carbon capture and storage (CCS) - trapping carbon dioxide from power stations and other sources and locking it away safely, deep underground.
The Norwegian oil giant Statoil has been doing this for more than a decade, and BP, with a working project in Algeria, is collaborating with Masdar on CCS in Abu Dhabi. This technology plays ideally to oil companies' geological skills. Finally, there is the job of replacing oil for transport. Biofuels, made from plants, are one of the most promising avenues, and now equal 5 per cent of the world's petrol consumption.
BP acquired Verenium's cellulosic biofuels business last month for nearly $100 million. Using cellulosic ethanol, made from the indigestible woody parts of plants, avoids competing with food production, one of the problems that have dogged biofuels' early progress. Biofuels fit well with oil companies' refining and fuel retail operations. Agriculture, though, is not their core skill, and they will have to find new ways of working effectively with farmers.
So oil companies do have a major role to play in developing some types of clean technology. Beyond this, rather than investing hugely in unfamiliar alternatives, their role is to return profits to society so that the specialists can do the job. It is therefore not surprising that oil companies are greeted with derision when they claim to be "beyond petroleum". But the instinctive hostility of environmentalists is also counterproductive. If genuine green investments attract only denunciation, oil companies may not make them at all.
In stamping out "greenwash", we have to be careful not to kill the green shoots. Robin M Mills is a Dubai-based energy economist and author of The Myth of the Oil Crisis