THE climate is warming at an alarming rate, but in some quarters the atmosphere is turning cold to the point of freezing. The announcement by the National Galleries of Scotland that it is to sever ties with BP has been claimed by environmental campaigners as a major victory. From next year, as part of their drive to combat the “climate emergency”, the National Gallery in Princes Street Gardens, and its partners the National Portrait Gallery and the Gallery of Modern Art, will have nothing to do with the oil giant. Thereafter, the BP Portrait Award exhibition will no longer be shown in Edinburgh, as for the last 10 years. Soon, this popular fixture in the arts calendar will be history.

The National Galleries are part of a wave of revulsion against those whose money comes from oil. The Royal Shakespeare Company parted ways with BP earlier in the year, and last month the National Theatre in London jettisoned Shell as a sponsor. Money from such household names is fast becoming toxic. These once courted companies, whose pockets arts bodies picked as nimbly as Fagin’s gang, are seen as tainted. Now, any such association between cultural outfits and oil titans is considered disreputable and dodgy. So fast is the fear of contagion spreading, you can almost hear the stampede as high-profile organisations distance themselves from any hint of alliance with the agents of carbon calamity.

At first sight, it is an entirely justifiable divorce. Who doesn’t want to see the petroleum industry vastly reduced, and eventually made redundant by renewable energy? Fossil fuels are now as big a source of shame as the tobacco industry once was, and those with sense are surely wise to keep their distance.

I worry, though, that the National Galleries’ virtue signalling has more to do with winning public approval than with the reality of tackling climate disaster. For a start, without patronage, the arts would never have got much beyond finger painting. Renaissance masters, be it Leonardo or Michelangelo, Botticelli or Filippo Lippi, eagerly took money from those who had earned it by questionable means. The filthy rich, among them some of the most amoral or ruthless individuals who have ever lived – bankers such as the Medici and the Strozzi, or the Vatican at the height of its pomp and corruption – commissioned art in the hope of buying salvation. Hence the kneeling portraits of individuals seeking absolution for their wealth and their sins in the corner of devotional masterpieces.

You can criticise BP, Shell and their ilk for continuing to plunder the earth’s carbon resources; you can view their generous funding of the arts as an utterly cynical PR exercise, a way of laundering their reputation; but you cannot deny that without the money they have given, the arts today would be much the poorer. What do we remember of the Medici? Very little. But the works of their beneficiaries, such as Raphael and Piero della Francesca, are still drawing crowds. In that sense, even the most venal medieval patron understood that in the end, art would long outlive opprobrium.

We are more enlightened about the origins of public funds today, of course. And there are more sustainable sources of income than the bank accounts of oil barons, though few, sadly, that gush to such a degree.

Yet what does this move by the National Galleries of Scotland actually achieve other than denting the cultural credentials of BP? A glance at its Board of Trustees shows that some have risen to eminence through banking and financial services. One, who is a specialist adviser on reputation risk and management, was until recently on the board of the Edinburgh International Festival. The EIF’s connection with BP also ended, three years ago.

Doubtless no board member of the National Galleries of Scotland, or the RSC or the National Theatre, is any more of a hypocrite than the rest of us. By initiating such an avowedly ethical step, however, they invite scrutiny. Are their savings and pensions invested in businesses that have nothing to do with fossil fuels? Do they drive electric cars, commute by bike, or eschew meat and dairy? Do they wear the same clothes year after year to reduce landfill and combat unsustainable levels of production? Are they never to be found in an airport departure lounge or, when travel is unavoidable, do they offset their carbon emissions?

The domino effect of organisations like theirs leaping from the oil rig smacks of moral panic and the dread of their image being tarnished. It remains to be seen, however, if it will also result in a profound commitment to reducing their institution’s carbon footprint.

Cutting down swathes of trees in Princes Street Gardens as part of the National Gallery extension, for instance, was not an environmentally friendly act. It was particularly egregious given the air pollution in Princes Street, where a terrace of once noble trees has been replaced by a smaller number of saplings. It will take years before they are big enough to act as lungs around the Scott Monument and Waverley Station. Meanwhile, part of the new extension eating into the gardens, which is intended to showcase Scottish art, is devoted to a much larger shop, commerce seemingly as crucial to its future plans as culture.

The biggest problem with reviling BP and others in the same line is that there is not one of us whose lifestyle is not still heavily – regrettably – dependent on oil and its by-products. Ending the alliance with this sponsor will indubitably have an adverse effect, in the short term at least, on artists.

Some will say that is a price worth paying. But however laudable the sentiment, the message it sends is no more than aspirational. Such an act alone will do nothing whatsoever to modify art lovers’ or gallery staff’s behaviour. The demand for oil will not be affected by refusing BP’s shilling. Indeed, ostracising the obvious suspects, who have a bullseye on their back, is merely a placebo. It makes everyone feel better, without effecting real and significant change.

Unless the announcement is followed by an audit of the way this institution is run, and actively encouraging the public to alter its behaviour, trumpeting the banishment of BP might be seen as simply playing to the gallery.