We have been living in a bubble, a bubble of false comfort and denial. In the rich nations, we have begun to believe we have transcended the material world. The wealth we’ve accumulated – often at the expense of others – has shielded us from reality. Living behind screens, passing between capsules – our houses, cars, offices and shopping malls – we persuaded ourselves that contingency had retreated, that we had reached the point all civilisations seek: insulation from natural hazards.

Now the membrane has ruptured, and we find ourselves naked and outraged, as the biology we appeared to have banished storms through our lives. The temptation, when this pandemic has passed, will be to find another bubble. We cannot afford to succumb to it. From now on, we should expose our minds to the painful realities we have denied for too long.

The planet has multiple morbidities, some of which will make this coronavirus look, by comparison, easy to treat. One above all others has come to obsess me in recent years: how will we feed ourselves? Fights over toilet paper are ugly enough: I hope we never have to witness fights over food. But it’s becoming difficult to see how we will avoid them.

A large body of evidence is beginning to accumulate showing how climate breakdown is likely to affect our food supply. Already farming in some parts of the world is being hammered by drought, floods, fire and locusts (whose resurgence in the past few weeks appears to be the result of anomalous tropical cyclones). When we call such hazards “biblical”, we mean that they are the kind of things that happened long ago, to people whose lives we can scarcely imagine. Now, with increasing frequency, they are happening to us.

In his forthcoming book, Our Final Warning, Mark Lynas explains what is likely to happen to our food supply with every extra degree of global heating. He finds that extreme danger kicks in somewhere between 3C and 4C above pre-industrial levels. At this point, a series of interlocking impacts threatens to send food production into a death spiral. Outdoor temperatures become too high for humans to tolerate, making subsistence farming impossible across Africa and South Asia. Livestock die from heat stress. Temperatures start to exceed the lethal thresholds for crop plants across much of the world, and major food producing regions turn into dust bowls. Simultaneous global harvest failure – something that has never happened in the modern world – becomes highly likely.

In combination with a rising human population, and the loss of irrigation water, soil and pollinators, this could push the world into structural famine. Even today, when the world has a total food surplus, hundreds of millions are malnourished as a result of the unequal distribution of wealth and power. A food deficit could result in billions starving. Hoarding will happen, as it always has, at the global level, as powerful people snatch food from the mouths of the poor. Yet, even if every nation keeps its promises under the Paris agreement, which currently seems unlikely, global heating will amount to between 3C and 4C.

Thanks to our illusion of security, we are doing almost nothing to anticipate this catastrophe, let alone prevent it. This existential issue scarcely seems to impinge on our consciousness. Every food-producing sector claims that its own current practices are sustainable and don’t need to change. When I challenge them, I’m met with a barrage of anger and abuse, and threats of the kind I haven’t experienced since I opposed the Iraq war. Sacred cows and holy lambs are everywhere, and the thinking required to develop the new food systems that we need, like lab-grown food, is scarcely anywhere.

But this is just one of our impending crises. Antibiotic resistance is, potentially, as deadly as any new disease. One of the causes is the astonishingly profligate way in which these precious medicines are used on many livestock farms. Where vast numbers of farm animals are packed together, antibiotics are deployed prophylactically to prevent otherwise inevitable outbreaks of disease. In some parts of the world, they are used not only to prevent disease, but also as growth promoters. Low doses are routinely added to feed: a strategy that could scarcely be better designed to deliver bacterial resistance.

In the US, where 27 million people have no medical cover, some people are now treating themselves with veterinary antibiotics, including those sold, without prescription, to medicate pet fish. Pharmaceutical companies are failing to invest sufficiently in the search for new drugs. If antibiotics cease to be effective, surgery becomes almost impossible. Childbirth becomes a mortal hazard once more. Chemotherapy can no longer be safely practised. Infectious diseases we have comfortably forgotten become deadly threats. We should discuss this issue as often as we talk about football. But again, it scarcely registers.

Our multiple crises, of which these are just two, have a common root. The problem is exemplified by the response of the organisers of the Bath Half Marathon, a massive event that took place on 15 March, to the many people begging them to cancel. “It is now too late for us to cancel or postpone the event. The venue is built, the infrastructure is in place, the site and our contractors are ready.” In other words, the sunk costs of the event were judged to outweigh any future impacts – the potential transmission of disease, and possible deaths – it might cause.

The amount of time it took the International Olympic Committee to postpone the Games could reflect similar judgments – but at least they got there in the end. Sunk costs within the fossil fuel industry, farming, banking, private healthcare and other sectors prevent the rapid transformations we need. Money becomes more important than life.

There are two ways this could go. We could, as some people have done, double down on denial. Some of those who have dismissed other threats, such as climate breakdown, also seek to downplay the threat of Covid-19. Witness the Brazilian president, Jair Bolsonaro, who claims that the coronavirus is nothing more than “a little flu”. The media and opposition politicians who have called for lockdown are, apparently, part of a conspiracy against him.

Or this could be the moment when we begin to see ourselves, once more, as governed by biology and physics, and dependent on a habitable planet. Never again should we listen to the liars and the deniers. Never again should we allow a comforting falsehood to trounce a painful truth. No longer can we afford to be dominated by those who put money ahead of life. This coronavirus reminds us that we belong to the material world.

• George Monbiot is a Guardian columnist