Existential Risks

By Joris Voorhoeve, Professor Emeritus International Organizations, Former Cabinet Minister of The Netherlands


The British philosopher Tony Ord has studied all risks that could seriously harm or even teminate mankind. They range from stellar explosions to pandemics and far going climate change.  Stellar explosions near the earth, a collision with a comet, or a supervolcanic eruption that might end human life as we know it, are estimated to occur not more often than once in 10.000 years (supervolcanic eruption) or once in 1000 million years (stellar explosion.). This category of risks consists of natural events which mankind cannot stop, but they can stop mankind. They are very hard to predict; there is little or no time to brace oneself. It may be better to be killed suddenly than to survive and die from the terrible consequences.

Risks that have to do with human behavior (man-made risks) are nuclear war, climate change, pandemics, and the other “anthropogenic” risks. This category is estimated at a total of 1 in 6 years (17%). Of these, nuclear war is estimated at 1 in 1000 years. That is arbitrary. This risk depends of course on military aggression and defense policies, as well as technical risks of devices going off unintended. The further spread of nuclear weapons to more governments than the present nine nuclear powers increases it. The safety of their control systems, success or failure in arms limitation treaties, the rationality or irrationality of governments and the possible spread of nuclear weapons to criminal and terrorist groups also affect this risk.

The total risk of a nuclear weapon going off can not be based on statistical analysis and remains a guess. I agree that this risk is very serious; it may be more serious than climate change. This depends on how many thermonuclear weapons  explode intentionally or by accident and a possible acceleration by poorly controlled artificial intelligence devices used for military purposes. Will there be automatic defense system responses, is there no time to communicate with opponents, and complete loss of rational control?

Such explosions may make human and other forms of life very difficult or even impossible. That is why Presidents Biden and Putin recently extended the treaty to limit the numbers of the heaviest nuclear weapons. But far more arms control measures are needed to bring the risk down significantly. My view is that complete abolition of nuclear weapons by good-willing governments does not erase the risk. The present nine nuclear weapons states have stated they will not disarm, and if some of them do but others do not, the risk that nuclear weapons are used to force victory in a violent conflict may even become higher than at present.

There is a nuclear stalemate between the two countries that have the most of such weapons, Russia and the US,  but they should bring the numbers down step by step, especially of those weapons that are very vulnerable to the first strike by an opponent. They should reach a “minimum deterrent” which makes it clear to opponents they should not use them under any circumstances. There is another risk, of course, and that is that counties like China, India, Pakistan, North Korea, Israel end Iran might use so-called “small nuclear weapons” that are in their effect large and horrendous.

Next comes the category of slower-moving disasters like climate change and pandemics. They are real, as every sensible human being should know by now, but in my view still underestimated. It has been calculated that the sea level will rise by about 30-80 meters when both the Arctic and the Antarctic ice masses have melted. Antarctica is already melting and it takes much stronger action than is taken now to stop this in the next decades. This may also change the ocean currents.

What will happen to the Gulfstream that warms the coastal areas of Western Europe? Will gradual warming, as is already taking place, lead to a new ice age in Northwestern Europe? When we know the answer it is probably too late to reverse it. Conclusion: expect the unexpected and try to reduce such risks a long time ahaed. Now that responsible management has returned to the White House, the time is ripe for better policies to at least curb the “man-made” risks.  How? see appendix F in Ord’s book for a short overview. Highly recommended, but not for bedtime reading.


Toby Ord, “The Precipice; Existential Risk and the Future of Humanity”, London etc., Bloomsbury, 2020, ISBN e-book 978-1-5266-0019-6.