The world is dying. Capitalism is unsustainable – lethal food, water insecurity, pandemics, sea level rise, extreme weather, lethal heat, megastorms, and ocean acidification. Overwhelms defense.

It would be a serious error to reduce the entire planetary ecological emergency signaled by the rise of the Anthropocene simply to climate change, as the other critical planetary boundaries, each of which represent an Earth System emergency, are being crossed as well, with immense dangers for humanity. For example, the biodiversity crisis stemming mainly from the destruction of the world’s ecosystems is arguably as serious as climate change. 45 Nevertheless, climate change currently threatens irreversible change on a scale and with a speed that has no counterpart. Carbon dioxide levels in the atmosphere are now “higher than at any time in at least two million years,” heating up the entire earth via the greenhouse effect. 46

Part 1 of Climate Change 2021: The Physical Science Basis, published in August 2021 by the United Nations Intergovernmental Panel on Climate Change (IPCC), indicated that even in the case of SSP1-1.9, the most optimistic scenario in its Shared Socioeconomic Pathways—in which carbon emissions would peak globally by 2025, a 1.5°C increase in global average temperature over preindustrial levels would be avoided until 2040, and the goal of net-zero carbon emissions would be reached by 2050—the consequences for global humanity would nevertheless be catastrophic by the measure of all historical precedents. 47 This would include various “compound” events of extreme weather, sometimes known as “global weirding” (including record heatwaves, persistent droughts, out-of-control wildfires, megastorms, torrential rainfall, unprecedented floods, glacial melts, and sea level rise), affecting every region and ecosystem of the world. The second-best scenario (also optimistic), in which global average temperature would be stabilized at less than 2°C (at around 1.7°C)—is a sort of last hope scenario and carries with it dangers disproportionately greater. 48 The other three scenarios are almost unthinkable, although more consistent with current trends, threatening the very existence of civilization and humanity itself.

Under the most optimistic scenario, or SSP1-1.9, in which 1.5°C is not reached until 2040, it is estimated that the mid-term (2041–2060) increase in global average temperature will remain in the 1.2–2°C range, with the best estimate 1.6°C, and then, near the end of the century (2081–2100), will fall back to 1.4°C due to the implementation of negative emissions technologies. 49 Yet, even in this highly optimistic scenario, extreme heat and heavy rainfall will be far more frequent. Sea level rise will persist over centuries and perhaps millennia. Ocean acidification will increase, carrying its own dangers. The best that can be hoped for at this point, therefore, according to the IPCC, is that the ultimate threat to humanity will be held off, and by the end of the century global average temperature could be reduced below 1.5°C again. Yet, even then, some of the negative effects of global heating, posing dire threats to billions of people, will nevertheless continue to play out over the twenty-first century. In the case of SSP5-8.5, the fifth and most apocalyptic scenario, resulting from the unhindered continuation of capitalist “business as usual,” global average temperature is projected to increase by the end of the century by 3.3–5.7°C, with the “best estimate” at 4.4°C, spelling absolute catastrophe for humanity and innumerable species on the planet. 50

The original “Summary for Policymakers” of part 3 of the Sixth Assessment Report, addressing “Mitigation,” which is not due to be published in its final form until March 2022, was leaked by Scientist Rebellion, a branch of Extinction Rebellion, in August 2021. 51 Although subject to being redacted by governments prior to final adoption and publication, the leaked version, accepted by scientists, argues that what is required, in order to avoid climate disaster, “is fundamental structural changes at global scale,” in accord with a “just transition” that ensures that “workers, frontline communities and the vulnerable are not left behind in low-carbon pathways.” 52 As the leaked chapter one of part 3 of the report on mitigation of climate change indicates: “The character of social and economic development produced by the nature of capitalist society” is viewed by many political-economic critics and radical ecological thinkers “as ultimately unsustainable.” 53 Indeed, a close reading of the leaked chapter one leaves little doubt that system change on a revolutionary scale is now the only remaining path to a sustainable future for humanity. As UN secretary general António Guterres exclaimed in a statement accompanying the release of part 1 of the new IPCC report, this is “a code red for humanity.” 54

In September 2021, over 200 of the world’s leading medical journals, including the British Medical Journal, the Lancet, the New England Journal of Medicine, the European Heart Journal, the Chinese Science Bulletin, the National Medical Journal of India, the East African Medical Journal, the Medical Journal of Australia, and the Canadian Medical Association Journal, simultaneously published an editorial titled “Promises Are Not Enough,” insisting that, given global heating, “only fundamental and equitable changes to societies will reverse our current trajectory” from the standpoint of the rapid deterioration in world health conditions. As the editorial states:

The risks to health of increases above 1.5° C are now well established. Indeed, no temperature rise is “safe.” In the past 20 years, heat-related mortality among people over 65 years of age has increased by more than 50%. Higher temperatures have brought increased dehydration and renal function loss, dermatological malignancies, tropical infections, adverse mental health outcomes, pregnancy complications, allergies, and cardiovascular and pulmonary morbidity and mortality. Harms disproportionately affect the most vulnerable, including children, older populations, ethnic minorities, poorer communities, and those with underlying health problems.

Global heating is also contributing to the decline in global yield potential for major crops, which has fallen by 1.8 to 5.6% since 1981; this decline, together with the effects of extreme weather and soil depletion, is hampering efforts to reduce undernutrition. Thriving ecosystems are essential to human health, and the widespread destruction of nature, including habitats and species, is eroding water and food security and increasing the chance of pandemics.

The consequences of the environmental crisis fall disproportionately on those countries and communities that have contributed least to the problem and are least able to mitigate the harms. Yet no country, no matter how wealthy, can shield itself from these impacts. Allowing the consequences to fall disproportionately on the most vulnerable will breed more conflict, food insecurity, forced displacement, and zoonotic disease— with severe implications for all countries and communities. As with the COVID-19 pandemic, we are globally as strong as our weakest member.

Rises above 1.5° C increase the chance of reaching tipping points in natural systems that could lock the world into an acutely unstable state. This would critically impair our ability to mitigate harms and to prevent catastrophic, runaway environmental change. 55

Underlying this planetary emergency associated with the first age of the Anthropocene, or the Capitalinian, is capitalism, or the system of capital accumulation. Capitalism is, in this sense, a faulty mechanism that has disrupted the larger Earth System of which it is a part. The logic of capital accumulation, which accepts no boundary beyond itself, now threatens in the era of catastrophe capitalism the very nature of existence on earth.