On the morning of 16 July 1945 in the deserts of New Mexico, a small group of scientists gathered in secret to witness the detonation of the first atomic bomb. The test – codenamed “Trinity” – was the subject of a bet among the group: how powerful would the explosion be? Strikingly, the majority significantly underestimated the power of their collective creation, whose blast was heard over 100 miles away, with a mushroom cloud blooming 7.5 miles into the sky. Indeed, only one apparently wore the full safety gear provided. And yet, as Robert Oppenheimer, mastermind of the bomb, later remarked, they had “become death, destroyer of worlds”.

In a summer of raging fires and a scorched earth, we are at an analogous moment. Our power has transformed the earth and its ecosystems, a transformation that deepens daily. As yesterday’s “Hothouse Earth” report from the Stockholm Resilience Centre – a leading research hub on sustainability and climate change - suggests, we risk triggering tipping points that could desolate large parts of the planet, rendering them uninhabitable. This is the reality of the Anthropocene, our new era in which human action is the decisive and destructive influence on the Earth’s ecosystems.

Just like the atomic scientists, we risk failing to grasp both our power and the scale of change hurtling towards us. This year’s British Social Attitudes survey showed that while most people believe climate change is happening, only a third of people in the UK think it is mainly caused by human activity. Meanwhile, only a quarter of people are very worried about climate change, less than the number who aren’t worried at all.

But whatever we think of it, from scorching temperatures to a planet on fire, the reality and violence of climate change is already upon us. Our impact – or more precisely, the impact of an extractive model of capitalism that has transformed our relationship with nature to the rhythm of capital accumulation – is deeper and more systemic than many realise.

We are now deep into ecological deficit. Resources are being consumed at around 1.7 times the Earth’s ability to regenerate them. We are living through the sixth mass extinction and nearly two-thirds of all vertebral life has died since 1970. The stubborn entrenchment of carbon into our economies means that we are highly unlikely to limit global warming to 1.5°C above pre-industrial levels, increasing the chance of severe climatic disturbance.Only radicalism can prevent an irreversible “Hothouse Earth”

Meanwhile, the global food system has destroyed a third of all arable land and, at current rates, global top soil degradation means that there may only be 60 global harvests left. In all, human activity has pushed environmental systems into “unsafe” operating spaces, threatening the preconditions upon which life can occur and societies flourish. Marx’s metabolic rift – ecological crisis under capitalism - is wide and growing.

The potential consequences were starkly set out in the Hothouse Earth report. While the cascading effects are less probable if temperature rises are kept to 2 degree rises or below, at least within the next few decades, it remains a possible and severe risk. And if we go sharply above that limit, then the severity of disruption escalates dramatically.

Of course, with many of the Earth’s natural systems tipping towards breakdown, “doomism” is tempting. But fatefulness –paralysis in the face of the magnitude of the task – is fatal. Critically we still have time to act: Hothouse Earth mustn’t – and doesn’t have to be - our future. The task then, to paraphrase Raymond Williams, is to make hope possible and galvanise action, rather than make despair convincing and immobilising.

What is clear is that surface level tinkering is the guarantee of deterioration on a dramatic and devastating scale. As the report puts it, “Incremental linear changes to the present socioeconomic system are not enough to stabilise the Earth System. Widespread, rapid, and fundamental transformations will likely be required to reduce the risk of crossing the threshold and locking in the Hothouse Earth pathway.”

The implications of this are stark and vital. We are living amid the ruins of a failing carbon civilization. Our societies, institutions and economies – which have generated the conditions of accelerating planetary breakdown – are simply incapable of delivering the scale and speed of transformation needed to avoid environmental collapse. The status quo is dead; politics just hasn’t caught up.

For sections of the right, environmental collapse of whatever intensity could prompt a doubling down on an exclusionary nation state, with increasingly violent borders thrown up to keep an unstable world at bay. But retreating behind barriers, an unequal sharing of the pain of climate change, and a reliance on technological “moonshots” for salvation cannot ultimately manage the challenges of the Anthropocene.

It would be a deeply unjust approach, not least given our outsized culpability for circumstances. But it would be an ineffective one too; it would fail to grapple with the socio-economic arrangements driving crisis, be replete with excessive risk, and cause vast and unneeded suffering.

For the left, the task is harder: to build a politics capable of transforming global socio-economic conditions to justly bring our impacts within safe planetary limits by the mid-century, while building and deepening resilience between and within communities and nations for the disruptions to come.

This will require political and economic imagination, capable of remaking at scale the core institutions that shape production and consumption, investment and the stewardship of resources. It will require a politics committed to democratic negotiation of the challenges of the Anthropocene, capable of collective restraint where necessary, while mobilising for shared, sustainable abundance where possible.

Reviving a limited social democratic project – which relied on a set of historically contingent circumstances such as the economic conditions of the “Great Moderation”, which have now come to an end, or an extractive, gendered and racialised international political economy that exacerbated the ecological deficit - is unlikely to suffice. In an age of instability, radicalism of intent is the only serious position, a position which demands – politically hard though it will likely prove - a corresponding level of international co-operation.

We have not yet become, like Oppenheimer and his bomb, “the destroyer of worlds”. But we are close. Our actions now will shape the types of future we and future generations experience. What is required in the Anthropocene is a more ambitious politics: a politics of will, seriousness, and imagination.

Mathew Lawrence is senior research fellow at IPPR and editor of IPPR Progressive Review. He works on project on understanding and responding to environmental collapse and tweets @dantonshead