What do you do with the contents of your daily bowel movement, when you live in a third-storey flat in the suburbs, and the water stops running into the toilet cistern so you can’t conveniently flush it away?

The urine bit is easy to trouble-shoot: you could still use the toilet bowl. But the paper would have to go into a dry bin, the way they do in some South American cities. To void your bowels, though, you’d probably need to squat over a sealable bucket, cover the offending matter with a cupful of sawdust, and jam the lid back on until next time you feel your bowels push. But what do you do when the bucket is full?

Capetonians seem to already have forgotten how close the city came to an almost unimaginable sanitation collapse just 18 months ago, after a three-year drought that was the worst in recorded history. We were within three months of running out of municipal water and the panic was palpable when the city announced wartime-type rationing plans in case dams fell below a critical threshold.

The plan was to shut off water to the suburbs, leaving everyone to queue for a thimble-sized handout: just 25 litres of water, per person per day, from 200 distribution points around the city. The usual mundane routine of work commutes, school runs, labouring for our salaries, or picking up groceries, would be thrown into chaos as we lined up with containers, waiting our turn at water trucks, with police hanging on the fringes in case things got nasty.

Suburban folk, their lives bubble-wrapped against the coarseness of shantytown people’s daily battles, nearly got a taste of what happens when a municipal grid fails.

What, indeed, do you do with your bodily waste when you live in a built-up city of more than four million people and the municipality can’t wash away your faeces anymore?

Social media groups were abuzz with do-it-yourself suggestions: what sorts of toilet systems could we put into our homes that could handle our waste, not stink the place out, and keep it from incubating disease? Dry-bucket systems could work, and maybe some entrepreneurial locals would grab the opportunity to set up small businesses that trucked through neighbourhoods to collect the contents of buckets and ship it off to a far-off composting site.

Two Fridays ago, as rolling mass protests tracked time zones around the world to raise the alarm on the urgency of our need to shut down carbon pollution and stabilise the climate, a small band of protesters in Cape Town marched down Roeland Street to Parliament. They joined the estimated four million people who took part in the global climate strike, but the crowd was thin, compared with many other countries.

New York had about 300,000 people on the streets, Berlin 270,000, London 100,000, Mexico City 35,000.

Cape Town had an estimated 2,000. The march on Sasol’s headquarters in Johannesburg, to demand actionable emissions cuts from an industry whose Secunda plant is the biggest single-source carbon polluting point on the globe, wasn’t more than about 400, according to march organisers.

There were many more smaller protests around the country, possibly as many as 20, but almost no coverage of this in the press.

Half the Cape Town crowd was school children and university students. Many of the rest were the same people who for years have been battling to get the climate crisis on to the political agenda: the same activist groups; some faith-based leaders and a few professors whose modelling and analysis on what an unstable climate means for our region make them among the leading world thinkers on this issue.

Where was the rest of Cape Town, particularly its middle class who finally got a taste of how quickly a climate shock can destabilise a city?

Outrage over women being brutalised in the country or issues of State Capture is what draws most protesters to the parliamentary buildings – and with understandably greater anger. But it seems most South Africans still can’t join the dots between what a rapidly destabilising climate means for us and how it will worsen the everyday development challenges we are struggling with. Challenges not just for the poor, but for everyone.

Water shortages will wither our food-producing farms or dry up city taps; people fleeing the drying countryside will throng into cities, putting greater pressure on their fragile services; climate shocks like floods, heatwaves and droughts could grind cities to a halt; political instability as food prices rise, water runs out and inequality grows, will ignite existing class tensions.

The drought which hit southern Africa between 2015 and 2018 was the worst in more than a century of record-keeping. In those years, rainfall varied between 50% and 70% of the long-term average, according to the University of Cape Town’s Climate Systems Analysis Group (CSAG), with many rainfall figures dropping to the lowest since written records began in the 1880s.

After the drought, researchers at CSAG, the UCT African Climate and Development Initiative (ACDI), and the Environmental Change Institute at Oxford University calculated that human-caused climate change made this drought about three times more likely to happen.

When relatively normal rains finally returned in the winter of 2018, Cape Town’s “Day Zero” emergency water rationing measures were put on hold. But that doesn’t mean they’re gone for good. The climate modelling is clear: near-crippling droughts like this are more likely to happen, more often, and it is hard to predict exactly when they’ll arrive and for how long.

A city like Cape Town already has about 180,000 families living in squalid conditions, without running water or toilets in their homes. They have to collect water in buckets from standpipes and use communal toilet blocks that often break or get backed up with filth. This is part of the service delivery backlogs that most South African cities have inherited after decades of unfair apartheid-era city planning.

But middle-class people, who are politically and economically powerful in our society, are insulated from the kind of misery that compels many other South Africans on to the streets to burn tyres in desperate protest.

The Day Zero water crisis in Cape Town was a reminder, even for the protected rich, that climate shocks like this drought don’t happen in isolation. They shatter open the slumbering fault lines of day-to-day development challenges, and potentially disrupt reasonable city function.

Without electricity to keep pumping water into our cities and siphon away our kilolitres of accumulated waste to treatment plants, city sanitation collapses. We have to keep the grid up, for this reason alone.

Right now, the government is reviewing the presidency-appointed Eskom Sustainability Task Team’s green finance plan, an $11-billion funding arrangement over 20 years that could salvage the ailing utility, which is financially and operationally crippled. If accepted, it will rebuild the grid, ratchet down our emissions because it switches to renewables, and will pool funds to support workers who will be left stranded as coal mining and power generation phase-out.

We must join the dots between this critical energy policy decision and what it means for the long-term health of our country.

Protest marches such as the climate strikes which took place last Friday are just a small lever in the bigger collective actions that we need to bring about the urgent political response to arrest climate collapse. They’re also a chance to take the temperature of the social consciousness of our times.

If the crowd sizes here in South Africa are any measure of our awareness, and the poor media coverage of the events are anything to go by, it seems we’ve quickly forgotten how close we came to having to resort to makeshift toilet buckets, and trying to mask the stench under a sprinkle of sawdust. DM