Add Homo sapiens to the Endangered Species List

Preventing extinction of species is a major concern of many countries in the world today. Legislation to accomplish this is usually based on an endangered species list. Such a list should include any animal or plant species that has been deemed likely to go extinct in a few generations. Listing would normally trigger protective actions to increase the population size of the dwindling species; these include introducing them to unoccupied suitable habitats and measures that would increase birth rates or decrease death rates. Unfortunately, one important species at risk in today’s world does not have a small population size or an endangered designation in any country. This is understandable, since the traditional actions to increase population size would likely speed, rather than delaying the species’ extinction.

The species in question is Homo sapiens, as the title has already revealed. Humans are not on any country’s endangered species list, even though many well-qualified analysts believe that extinction could easily occur in the coming few decades (1-2 human generations). Human collapse or disappearance is certainly more likely if the global political scene does not change dramatically and soon. Experts generally agree on the two most likely mechanisms underlying potential human extinction: (1) continued or increased greenhouse gas emissions; (2) nuclear war. Noam Chomsky (among many others) has repeatedly warned of these dual risks in recent years. Both mechanisms are promoted by increases in the human population size. One important consequence of either mechanism is that it will lead to the collateral extinction of a huge number of other species.  Thus, the relationships of the U.S. government with those of Russia and China, and all three countries’ policies regarding greenhouse gas emissions have major implications for the survival of a large fraction of the earth’s species.

The interdependence of the climate crisis and nuclear war is seldom analysed. However, both potential causes of human extinction act in part by producing climate changes that would destroy a large amount of global agricultural production for a significant period, and thereby cause mass starvation.  A large-scale nuclear war would immediately inject enough particulates into the stratosphere to cool the earth and eliminate agriculture in most areas for the following two years.1 This, in turn, would probably kill almost all surviving human beings. Warming due to greenhouse gas production will also eliminate a good deal of agricultural and other plant production, leading to starvation.  Atmospheric warming effects would occur over a somewhat longer time span than those of a war, and the effects would vary greatly across space.  Although the consequences for human population size will initially be less dramatic, greenhouse-gas-driven climate changes will be much longer-lasting than those from a nuclear war. The effects of warming on human populations are already substantial.  The U.N. has recently assessed that hunger affects 122 million more people than it did four years ago.

Climate change is almost universally expected to raise international tensions, as different countries experience different changes in their weather patterns.  Greatly increased migration, water diversion/competition, food shortages, and other tensions provoked by the uneven effects of, and responses to warming are likely to generate military responses in some cases.  Those involving nuclear-armed states would have a potential escalate to the use of nuclear weapons.  In turn, the risk of war accelerates warming by diverting funding that could potentially reduce greenhouse gas emissions to the high CO2-producing activities of military production.  Thus, the two risk factors are mutually reinforcing.  As with all positive feedback loops, situations can change extremely rapidly.

If large-scale nuclear war occurs first, global warming will be basically irrelevant for the first two years of darkness.  Even without many humans left, warming could still be an issue after that, depending on the natural processes involved.  If global warming reaches a sufficiently advanced stage to cause mass mortality in the populations of one or more large countries first, nuclear war becomes much more likely as a result.

Either of the two likely causes of human extinction/near-extinction will also lead to large numbers of plants and animals going extinct, as the tolerance ranges of many species will be exceeded.  The occurrence of war would likely cause extinction of most of the vertebrate species currently on endangered species lists, with continued warming also representing a major cause of extinction. Vertebrates are less likely to be able to shelter in microenvironments with more suitable temperatures under either mechanism. Species with relatively small spatial ranges are most likely to go extinct.  Organisms with short generation times or resting stages that can persist for many years would have the best chances being able to survive either human-caused disaster. Having relatively long generation times, most vertebrates’ abilities to evolve quickly under new climate regimes are limited.  By leaving out the likely future actions by the human population under current governance, the current laws regarding endangerment of other species are ignoring one of the most likely drivers of their extinction.

How likely is it that future human actions will prevent these two linked threats to their own existence and that of many other species? The track record of past human responses to each of the threats has been abysmal.  More disturbing is the fact that the current global political system actually promotes both global military conflict and the higher emissions that fuel global warming.

The rise in greenhouse gases and global temperature are well-documented, so there is no question about risk increasing.  Greenhouse gas concentrations have continued to increase over the 3+ decades that there has been scientific consensus over the need for action to prevent further increases. There is less certainty about how rapidly human death rates will increase and standards of living decrease in response to the resulting climate change. It is still possible for these adverse effects to be slowed by some future emissions reductions.  However, the weather record for 2023 thus far is showing that previously predicted climate changes are likely to be underestimates.  Despite many previous international agreements to reduce CO2 and methane emissions, those decreases have not occurred on a global scale (other than a brief blip due to covid lockdowns).  Ignoring targets has been economically advantageous to high-emission countries in the short term.  Increases in the size of the human population, and the distraction of conflicts between countries have concurrently made the targets more difficult to achieve.

The future change in the risk of nuclear war is much more difficult to quantify than is warming.  The only widely used measure of risk is the Bulletin of the Atomic Scientists’ Doomsday Clock, which is now closer to midnight than ever before.  While the exact setting is not based on quantifiable components, there is no question that the decrease in remaining seconds does reflect greater risks.  The abrogation of nuclear treaties over the past ten years and the continual modernization of weapons stocks in the two largest nuclear powers (U.S. and Russia) over the past two decades have both increased risks. U.S.-Russia relations have been deteriorating steadily for the past two decades.  The war in Ukraine is currently the single process most likely to lead to the use of nuclear weapons.  Ending that conflict before the nuclear stage has become steadily less likely over its 550+ day course, as more Russians and Ukrainians have died, and as the U.S. and NATO continue to exceed many previous ‘red-lines’ in sending more and more-dangerous weapons to Ukraine (most recently, cluster munitions).  Greater numbers of commentators and government officials on both sides have argued for actual use of nuclear bombs.

Under the present system of largely country-based decision-making, averting extinction due to either war or warming requires implementing effective counteractive policies by the countries that contribute most to the risk factors. Fortunately, nuclear weapons are only possessed by a small number of the world’s countries, and most greenhouse gases are also produced by a relatively small subset of countries. Unfortunately, agreement within either of these groups of countries has not proven possible over the many decades since both problems were recognized.  The lack of effective international agencies regulating either process has meant that countries have been free to pursue policies that have (or appear to have) short-term local benefits. This is a common problem of decision making between competing entities, whether those entities are individuals or groups of individuals, and whether the species is human or nonhuman.

Both biological evolution and human decision making are driven by the short term consequences of actions to individual entities.2  Under modern political organization the entities are political leaders, who are likely to put more weight on winning the next election rather than on the persistence of their country. They are also likely to falsely equate these two goals.  Humans have an evolutionary history of inter-group conflict involving violence.  The ease of producing inter-group hatred and violence has been reflected in previous conflicts; for example, World War I,3 and both U.S.-led wars in Iraq.4  Western news outlets, reflecting the views of political leaders, have been generating highly biased news about Russia for many years now, making it easier to sustain support for the current war in Ukraine.  This is the main factor in the current risk for nuclear conflict.

There has not yet been any sign of a move towards a ceasefire or peace negotiations in the Ukraine war.  John Mearsheimer has recently written, “Is a meaningful peace agreement possible? My answer is no. We are now in a war where both sides – Ukraine and the West on one side and Russia on the other – see each other as an existential threat that must be defeated. Given maximalist objectives all around, it is almost impossible to reach a workable peace treaty.”5 This leaves the question of how a nuclear war can be avoided.  Mearsheimer’s article appeared before the recent NATO meeting at Vilnius.  This gathering ended up promising Ukraine eventual membership, even though preventing NATO membership was the stated primary motivation for the original Russian invasion.  It is a recipe for perpetual war.  That war could easily become nuclear if the Russian government felt itself to be losing, but the NATO summit guaranteed that the current members would keep arming Ukraine until it ‘won’ the conflict.  The war has already led to remarks by some U.S. and Russian politicians and academics that nuclear weapons should be used.

The current demonization of Russia in the West makes it very difficult for the U.S. to avoid sending troops or directly attacking Russia if Ukraine is clearly losing.  If, on the other hand Russia was clearly losing, its current government, or its successor would almost certainly use nukes (previous President Dmitri Medvedev has said so publicly).  The extreme negative commentary on Russia in western NATO/media also makes it almost impossible for the West to accept any peace proposal that would be acceptable to the Russians.  If any of the Eastern European NATO members independently chose to join the war before the U.S., it would be obliged to join them.  This would not be NATO’s first ill-advised military venture.  Over the last three decades NATO has grown greatly, engaged in several aggressive wars, and become more obviously an arm of U.S. foreign policy, which has itself become more militaristic.  Alfred de Zayas has recently written that, “The bottom line is that … NATO forces since the 1990s have committed war crimes and crimes against humanity…, what is important today is that world public opinion recognizes NATO as a threat to the peace and security of humankind. Its serial provocations constitute the greatest danger to our survival as a species.”6 de Zayas expands on this theme in a subsequent article.7 It is particularly disturbing that all NATO members have just agreed to contribute a minimum of 2% of their GDP to NATO. In the case of my country (Canada), this is $40-45 billion, approximately the same as the total federal contribution to health care in a country where the public health care system is rapidly falling apart.  Canada and the U.S., as well as many other western nations, are prioritizing death over life.

A growing number of academics have issued warnings of the risk of a nuclear war growing out of the Ukraine conflict. These include prominent academics like John Mearsheimer (University of Chicago), Alfred de Zayas (Geneva School of Diplomacy), Richard Falk (University of California, SB) and Jeffrey Sachs (Columbia University). Prominent journalists, including Glenn Greenwald, Jonathan Cook, Seymour Hersh, Aaron Maté and Jackson Lears, have made similar warnings. These, and other critics of current Western government foreign policies are largely shut out of mass media. With growing provocations of both Russia and China by the U.S., it seems increasingly unlikely that peace can be maintained.  The uniformity and bellicosity of foreign policy views of the mainstream media in the West seems to be increasing much more rapidly than any indicator of climate change.

The immediate hope is that at least one of the two main countries involved in policy determination in the Ukraine war (the U.S. or Russia) will change policy and interrupt the immediate process of escalation before it is too late.  However, this possibility has been decreasing over time and seems likely to continue to do so.  A major reason is the already weak position of the U.S. president (and declared candidate for 2024) in public opinion polls.  Admitting that sending 50 – 100 billion dollars to Ukraine had not produced any positive results would likely make a Biden victory impossible.  Vladimir Putin also faces an election in 2024, but his current within-country approval rating is approximately double Biden’s, possibly giving him a greater ability to make locally unpopular decisions.

The degree of non-nuclear escalation that causes a nuclear war to begin is impossible to predict.  Even if war over Ukraine is avoided, there the growing possibility is that the U.S. will simply shift its main military focus from Russia to China.  Tensions have already been ramped up by unnecessary weapons transfers and top U.S. political figures visiting Taiwan.  The manufactured Chinese ‘spy-balloon’ scare in February has also generated hostility towards China for no apparent reason.  Canada has lately been generating tensions with China with vague unsubstantiated stories of Chinese ‘meddling’ in Canadian politics. Even the wording of these stories is strikingly similar to the now discredited ‘Russian meddling’ stories in the U.S.

The current lack of action on climate change, and negative action on avoiding war provide lessons on some general principles would be needed in an Endangered Human Species Act. It is obvious that international bodies must have more power that they currently do.  They must also be less susceptible to manipulation by wealthy countries than the U.N. is today.  All countries need to have greater separation between government and media; that is particularly true in the U.S., where intelligence agencies have interfered massively in online media. Humankind must acknowledge the susceptibility of individuals in one group to supporting violent conflict with those having other affiliations; steps must be taken by governments to counteract this psychological flaw.  In the longer term, a smaller global population size would reduce many of the pressures for between-country conflict, as well as energy use.

Even if they were favoured by most people in most nations, these suggested principles probably won’t be applied quickly enough to reverse the growing risk of self-annihilation during the remainder of this decade.  However, some movement on one or two of the factors mentioned here could provide a longer time window in which to achieve the others. If the intertwined risks of extreme climate change and nuclear war are avoided, it will preserve many thousands of other species as well as our own.


  1. Ellsberg, Daniel 2018. The Doomsday Machine.
  2. Abrams, P. A. 2022. Competition Theory in Ecology. Oxford University Press.
  3. Hochschild, A. 2022. American Midnight. Mariner Books.
  4. Solomon, N.  2023. War Made Invisible. The New Press.
  5. Mearsheimer, J.J. Substack post, June 23, 2023.
  6. de Zayas, A.  CounterPunch, July 15, 2023.
  7. de Zayas, A.  CounterPunch, July 19, 2023.
Peter Abrams is an Emeritus Professor of Ecology & Evolutionary Biology at the University of Toronto, and recently published, Competition Theory in Ecology (Oxford University Press) about competition in natural systems. Read other articles by Peter.