Mother’s Beach, Mornington. I’m eight years old – my son’s age now. This is the last day of my swimming safety course. I’m wearing jeans, boots, t-shirt and hoodie, but I’m still shivering. I jump from the pier into the green-grey froth to tread water for 10 minutes. I’m still fully clothed, but keeping afloat is not a problem. The problem is jellyfish: thousands of gelatinous morning-glories, bobbing about me.

I grew up with jellyfish: they were part of my summers. I loved diving underneath their fronds and watching them flap and float, silhouetted by the sea’s silk mirror. But at Mother’s Beach, their intricate geometries lost their charm. Massed like that, they seemed malicious, not elegant. The sublime became horrific.

This Lovecraftian vision of translucent tentacles keeps coming back to me, as I think about our planet’s future. Reviewing Lisa-ann Gershwin’s Stung! for the New York Review of Books, Tim Flannery reports that jellyfish may eventually have the run of the oceans.

Already the water’s warming, making it more comfortable for tropical jellyfish. Overfishing, as with anchovies, means the jellyfish have fewer predators. Fertilizer runoff depletes oxygen in the water – jellyfish, with their lower metabolisms, are fine. Carbon in the oceans is increasing acidification, which eats away at the shells of shellfish – jellyfish, with no shells, are seemingly not threatened.

Jellyfish excrement feeds bacteria, which produce carbon dioxide. Jellyfish also eat massive quantities of plankton. Plankton eat carbon-rich foods at the top of the water, then their waste falls as pellets to the bottom. Less plankton and more bacteria means even more carbon, which feeds the cycle. If this occurs widely enough, it will hasten global warming, which will warm the oceans further, increasing the spread of jellyfish. Ditto for increased acidification.

550m years ago, jellyfish were apparently in charge. They might be again. Flannery quotes Gershwin’s conclusion: “No coral reefs teeming with life. No more mighty whales or wobbling penguins. No lobsters or oysters. Sushi without fish.”

A billion people get their protein from fish, and half a billion people are financially reliant on the fishing industry. Meanwhile, the dangers of jellyfish stings are well known. But even dead, jellyfish are dangerous: they get sucked into engines and cooling vents, for example. As Flannery reports, so far jellyfish have knocked out a coal power plant, a nuclear aircraft carrier, and capsized a Japanese trawler.

Gershwin’s is a grim vision. And it’s just one part of the so-called Anthropocene: a human geological age. The bigger picture is worse still. Physical and social scientists sketch a planet beset by mass extinction, more cyclones and droughts, starvation, violence, refugee crises and weakened nation-states. Civilisation as we know it, as Roy Scranton put it recently for the New York Times, “is dead already”.

A survivor walks among the debris of houses destroyed by typhoon Haiyan in the eastern Philippine island of Leyte. Photograph: Noel Celis/AFP/Getty Photograph: NOEL CELIS/AFP/Getty Images

What do we do? Many recommend an immediate political, economic and technological response. We, as concerned citizens, often say world leaders ought to sign emissions protocols; that scientists ought to study climate change with honesty and intelligence; that journalists ought to report the scientific findings without bias; that engineers ought to develop new technologies. And certainly many believe that scholars in the humanities and social sciences ought to analyse the various social and psychological causes of climate change.

But what ought the art world do? Not only visual artists, poets and philosophers, but also curators, art educators, gallery directors? What ought artists do in reply to environmental destruction?

First, two points about what I’m not asking here. I’m not asking “Is climate change real?” That’s a fine question, but I’m not qualified to answer it. But those who are have produced several reports on the physical causes of climate change, the likely consequences for the planet, and how to avoid these.

The IPCC assessment reports are prepared by hundreds of experts, and peer reviewed by thousands. They report that “it is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.” And just in case you’ve forgotten about the jellyfish, the IPCC also report: “The ocean has absorbed about 30% of the emitted anthropogenic carbon dioxide, causing ocean acidification.”

So I’m going to respect scientific authority here, just as I do with bosons, mitochondria and all the other things we accept because they’re not politicised.

I’m also not asking: “What can artists do?” That is, I’m not talking about the power of art to goad, suggest, intimate, or somehow transform. I’m confident that art can, in some circumstances, with some people, make a real difference to what’s thought and felt and achieved, but I want to consider something else: if we say artists ought to help us live better environmentally, what does this mean?

First up, it helps to identify exactly what “ought” means. And there are at least three ways to think of this, chiefly informed by philosopher Immanuel Kant’s Groundwork of the Metaphysics of Morals:

A) casual counsel

B) dutiful command

C) practical welfare

A) Casual counsel is all about preferences: if you like this then you ought to do this. If you like salt, then buy pretzels or anchovies (if there are any left in the oceans). If you like anaesthetising explosions with no human complexity, then watch Michael Bay’s Transformers films. The “ought” in casual counsel is about things that are not vital. So we can’t give casual counsel about the end of civilisation as we know it. “Look, if you happen to like food, financial and physical security, then you ought to help us. If not, no worries!” Unless you’re a nihilist (and you might be), there is no “if” about life.

B) Dutiful command has no “if”. Duty is something you must to, otherwise you’re not acting ethically. It might take this form: you ought to treat all life, insofar as you can, as an end in itself. In other words, duty is opposed to so-called instrumental thinking, which is when we treat things purely as the means to an end. We value them extrinsically rather than intrinsically.

In fact, this has been the response of some thinkers and activists, including some deep ecologists like Arne Naess. They see the environmental crisis as partly the consequence of instrumental thinking, applied to all life. For instrumentalists, plants and animals (including humans) only have exchange or use value, so it doesn’t matter if we acidify the oceans or clear forests – as long as it makes a profit.

Commercial fishermen form the words "acid ocean" during an event held to spread the message of saving the oceans from acidification caused by fossil fuel emissions, in Homer, Alaska. Photograph: Lou Dematteis/Reuters Photograph: LOU DEMATTEIS/REUTERS

So, we might say to artists: you ought to respect, recognise and represent all life as an end in itself. Not chiefly because of what this will achieve (although it might help), but because this is the very basis of an ecological morality. Ethics, in this view, is about doing what’s right, not because you want to, or because you think it will have benefits – you do right because it’s right.

This is certainly a reasonable and admirable command – it’s just unlikely to make a big difference. Even if many in the art world thought this way – and many, for various reasons, won’t – it’s hard to believe the rest of the population will suddenly overturn their basic philosophy of life. We are often utilitarian creatures: it’s often tough to value other humans as ends in themselves, let alone something as abstract as a biosphere, or as small and faraway as plankton. Then when we add the market, and professional identity within this market, dutiful command is often likely to fall on deaf ears.

My point is not that duty is wrong. My point is not that it’s powerless – some artists and audiences might be profoundly inspired by this. But, given the high stakes, dutiful command isn’t particularly practical. It can’t and won’t be the only response to climate change.

C) So let’s try practical welfare. This “ought” involves an “if”, but it’s not just a preference; it’s not trivial or superfluous. Welfare is about things like survival and flourishing – things most of us want by virtue of being alive. Regardless of how we value life, much of what’s worthwhile in civilisation will be lost if we can’t stop polluting the planet as we currently are. So, we might say to the artworld: if you want our species to thrive,you ought to help minimise climate change. (This might take a negative or positive form, eg “we’re screwed if we don’t do something right now” or “look at the better world we can make if we do something right now”).

This is certainly more likely to work; to appeal to many artists, and ordinary citizens. A bold message of fear or hope, which speaks of human welfare, might be a stronger driver than a message of the value of all life. Bear in mind, it needn’t be our welfare, as individuals in 2014. It might be that of distant others – in distant places (eg Pacific islands) or distant times (eg our great-grandchildren). The point is we’re linking the “ought” to a very specific and necessary “if”: survival and flourishing.

Massachusetts environmentalists converged on the city of Salem to demand an end to fossil fuel use. Photograph: Paul Weiskel/Demotix/Corbis Photograph: Paul Weiskel/ Paul Weiskel/Demotix/Corbis

What are some problems with this “ought” of practical welfare? A few come to mind. Asking too much of artists, asking too little, and treating artists instrumentally.

First: asking too much. Not all artists will be driven by the messages of welfare or duty; not all artists will hear the “ought”, or have the will to respond. There are as many hobby-horses as there are riders. Those who are driven to respond will be a small part of a much larger movement. This movement will require the cooperation and creativity of millions, all over the planet, in many fields and sectors. It will require big, national and international projects, and countless small, autonomous initiatives. It will require market solutions and government intervention, advertising and novels, protests and backroom negotiations. In short: it’s not just up to us, as artists.

Second: asking too little. As a writer, I can use my words and public profile to goad, seduce, nudge and inspire (well, I can try.) But I’m also a voter, father, colleague, neighbourhood citizen, consumer and so on. Any response to climate change will not just be professional – it will also happen as I read to my kids, cook meals, talk to school parents, and so on. It will be part of my housing choices, transport choices, furniture choices.

I’m not suggesting we can be perfectly “green”; that we can somehow opt out of capitalism and its filaments of exploitation. I’m suggesting that artists will respond to climate change in more than just their artistry. And, of course, some of the most compelling artworks will speak to this everyday constellation of habits, impressions and vague ideals. In short, the point is: we’re not just artists. We have other powers too.

Finally, as artists, can we always have our own ends, or will we sometimes be means? If we appeal to practical welfare, we’re asking artists to help solve a problem. And it’s not only an aesthetic problem – it’s a behavioural and ideological problem. My question is this: just how effective can art become, and at what point does it become advertising? Might artists be more like medieval craftsmen, promoting a very particular ethical vision?

As Pierre Bourdieu notes in Distinction, fine art developed its autonomy in the Renaissance to become something like a liberal art. It gained prestige and some measure of authority over its own means and ends, both of which grew well into the modern age. There is also a very strong tradition of artists resisting instrumental thinking, at least with their own work.

If we believe art can be a powerful force in slowing or stopping the worst of climate change, just how willing are we to use artists, or to be used, in this project? (And this is a question, by the way, for scientists and philosophers as much as for painters, sculptors or dancers.) There is no one answer to this, but the question is worth keeping in mind. How much control do we want?

I’ll end as I began. This is a poem by Marianne Moore, called The Jellyfish:

Visible, invisible, a fluctuating charm an amber-tinctured amethyst inhabits it, your arm approaches and it opens and it closes; you had meant to catch it and it quivers; you abandon your intent.

• This is an edited version of a keynote lecture delivered to the panel ‘Climate change: what role for the arts?’, organised by Climarte for the Melbourne Sustainable Living Festival