Last week, the journal Biological Conservation published an article that, while perhaps methodologically limited, made a credible case that the worldwide disappearance of insects foreshadowed a “catastrophic collapse of nature’s ecosystems”.

But the scariest aspect didn’t receive sufficient attention.

The scientists don’t attribute the extinctions primarily to climate change. They blame multiple causes, particularly habitat loss, pollution and pesticides.

In other words, the climate emergency on which most of us have been focused must be understood as one aspect of a broader disaster pertaining to humanity’s relationship to nature.

How will politicians respond?

After last week’s parliamentary clown show, many commentators justly bemoaned the low standard of leadership in Australia, with some urging a return to the centrist stability of the Hawke, Keating and Howard governments.

Yet that comparison actually reveals the deeper issues underpinning today’s political dysfunction.

Bob Hawke won office in 1983 after heading the ACTU, a body that then represented more than half the workforce. He promised unionists an increased standard of living through a “social wage”; he convinced employers he’d restrain labour militancy. His Accord gave Labor a real base and thus the stability to implement a neoliberal program that, at the time, no conservative politician would have dared advocate.

John Howard, by contrast, intensified neoliberal reform via a full-frontal assault on a labour movement weakened by the Accord and increasingly resented by capital. He thus united neoliberals and social conservatives behind big business and against the unions.

The situation today could not be more different.

Since Howard’s defeat, tension between Liberal wets and dries has become endemic, with Scott Morrison merely the latest leader tilting from one faction to the other according to the shifting political winds. The chaos reflects not the failure of individual politicians but an inability to present a coherent political project behind which the right’s traditional support base might be mobilised.

Similarly, Hawke won power with an astonishing 78% approval rating, while the latest polls put Shorten at an equally remarkable negative 15. Again, that’s not a personal flaw but indicative of a deeper uncertainty about who and what Labor represents, given its declining links to its traditional constituency.

In 1983, Hawke convinced organised labour to back an Accord meant to transform the economy on workers’ behalf.

In 2019, with the union movement greatly diminished, Shorten offers at best tepid support to the ACTU’s Change the Rules campaign.

The ALP’s likely victory in the next election thus reflects public disdain for the Liberals rather than enthusiasm for a Labor project.

We’re set for a familiar pattern: an unpopular leader with no real agenda or mandate, fending off internal challenges, and reliant on culture war and media stunts to beat back the opposition.

The absence of a stable social base leaves governments without the authority to tackle difficult issues.

The parliamentary convulsions accompanying the medevac bill provide an obvious example, with asylum seeker policy still based on piecemeal, ad hoc expedients slung together in response to an immediate crisis and then retained indefinitely in lieu of anything better.

Yes, the politics of borders are complicated. But they don’t present nearly as much of a challenge as the environmental situation.

We know that the biggest threat to insect populations comes from industrial farming. The advanced economies increasingly rely on unsustainable agricultural techniques, intensive use of pesticide and fertiliser, and the systematic clearance of forests, so much so that experts attribute about two-thirds of the loss of wildlife to food manufacture.

Furthermore, according to the World Resources Food Institute, production must rise by half in the next 30 years just sustain the growing world’s population.

In other words, any meaningful response to “insectageddon” requires fundamental changes in agriculture and thus the world economy – even as we address the separate but related problem of climate change.

Can you imagine a single contemporary politician putting forward a program for that?

Think of the agonised process that eventually resulted in marriage reform. Equality required merely a simple (and overwhelmingly popular) legislative change. And yet successive parliaments tied themselves in knots failing to deliver it – until a public campaign delivered the extra-parliamentary yes vote that broke the deadlock.

Indeed, the popular mobilisation for marriage reform hints at the only way out of the mess that we’re in.

Even if parliamentarians wanted to address the environmental emergency (and clearly many of them don’t), they no longer possess the kind of support base to deliver radical change.

That’s why, as the school students leading climate strikes have realised, we need to build our own constituency for action, creating the kind of mass movement that makes change impossible – even for politicians – to resist.

• Jeff Sparrow is a Guardian Australia columnist