Human extinction

Some of the many possible contributors to anthropogenic hazard are climate change, global nuclear annihilation, biological warfare, weapons of mass destruction, and ecological collapse.[4] In the 19th century, human extinction became a popular topic in science (e.g., Thomas Robert Malthus's An Essay on the Principle of Population) and fiction (e.g., Jean-Baptiste Cousin de Grainville's The Last Man).[4] Lord Byron wrote about the extinction of life on Earth in his 1816 poem "Darkness", and in 1824 envisaged humanity being threatened by a comet impact, and employing a missile system to defend against it.Writing about these findings in 1983, Carl Sagan argued that measuring the severity of extinction solely in terms of those who die "conceals its full impact", and that nuclear war "imperils all of our descendants, for as long as there will be humans.In 2003, British Astronomer Royal Sir Martin Rees published Our Final Hour, in which he argues that advances in certain technologies create new threats to the survival of humankind and that the 21st century may be a critical moment in history when humanity's fate is decided.[15] Potential anthropogenic causes of human extinction include global thermonuclear war, deployment of a highly effective biological weapon, ecological collapse, runaway artificial intelligence, runaway nanotechnology (such as a grey goo scenario), overpopulation and increased consumption causing resource depletion and a concomitant population crash, population decline by choosing to have fewer children, and displacement of naturally evolved humans by a new species produced by genetic engineering or technological augmentation.Natural and external extinction risks include high-fatality-rate pandemic, supervolcanic eruption, asteroid impact, nearby supernova or gamma-ray burst, extreme solar flare, and alien invasion.[16][24] Paleobiologist Olev Vinn has suggested that humans presumably have a number of inherited behavior patterns (IBPs) that are not fine-tuned for conditions prevailing in technological civilization.Physicist Willard Wells points out that any credible extinction scenario would have to reach into a diverse set of areas, including the underground subways of major cities, the mountains of Tibet, the remotest islands of the South Pacific, and even to McMurdo Station in Antarctica, which has contingency plans and supplies for long isolation.[3] Multiple scholars have argued based on the size of the "cosmic endowment" that because of the inconceivably large number of potential future lives that are at stake, even small reductions of existential risk have great value.In one of the earliest discussions of ethics of human extinction, Derek Parfit offers the following thought experiment:[51] I believe that if we destroy mankind, as we now can, this outcome will be much worse than most people think.There are many other possible measures of the potential loss – including culture and science, the evolutionary history of the planet, and the significance of the lives of all of our ancestors who contributed to the future of their descendants.[55]Philosopher Robert Adams in 1989 rejected Parfit's "impersonal" views but spoke instead of a moral imperative for loyalty and commitment to "the future of humanity as a vast project..."[56] Philosopher Nick Bostrom argues in 2013 that preference-satisfactionist, democratic, custodial, and intuitionist arguments all converge on the common-sense view that preventing existential risk is a high moral priority, even if the exact "degree of badness" of human extinction varies between these philosophies.[69] Jean-Baptiste Cousin de Grainville's 1805 science fantasy novel Le dernier homme (The Last Man), which depicts human extinction due to infertility, is considered the first modern apocalyptic novel and credited with launching the genre.[70] Other notable early works include Mary Shelley's 1826 The Last Man, depicting human extinction caused by a pandemic, and Olaf Stapledon's 1937 Star Maker, "a comparative study of omnicide".[4] Some 21st century pop-science works, including The World Without Us by Alan Weisman, and the television specials Life After People and Aftermath: Population Zero pose a thought experiment: what would happen to the rest of the planet if humans suddenly disappeared?[71][72] A threat of human extinction, such as through a technological singularity (also called an intelligence explosion), drives the plot of innumerable science fiction stories; an influential early example is the 1951 film adaption of When Worlds Collide.