Historically, what are some of the emerging technologies that were said by some, would destroy the world or create much harm?

Killer Grok:

New technologies have repeatedly triggered predictions of civilizational collapse, moral ruin, mass death, or the end of the human species. Some of those warnings were exaggerated or simply wrong. Others pointed to real harms that did materialize (though rarely at the “end of the world” scale originally advertised). The pattern is old.

Printing press (15th–16th centuries)

Critics called it a “whore,” the devil’s work, and a threat to both piety and social order. Scribes’ guilds smashed presses and drove printers out of towns. Church authorities feared cheap books would spread heresy, vice, and unauthorized readings of Scripture, undermining clerical control. Pope Alexander VI threatened excommunication for unlicensed printing. The technology did help fuel the Reformation, religious wars, and later moral panics (including printed witch-hunting manuals). Censorship systems such as the Index Librorum Prohibitorum followed.

Industrial machinery and the Luddites (early 19th century)

Powered looms, spinning frames, and other textile machines were accused of destroying skilled livelihoods, deskilling work, flooding markets with shoddy goods, and tearing up traditional communities. Luddites smashed machines they saw as being used “in a fraudulent and deceitful manner.” Broader commentators warned that mechanization would make people “mechanical in head and in heart.” The factory system did impose harsh conditions, child labor, and urban squalor even as it raised overall output.

Railways and steam power (19th century)

Doctors and others claimed speeds above ~20 mph would asphyxiate passengers, dislocate bones, or produce “railway spine” and nervous collapse. Trains were said to drive people mad (“railway madmen”), ruin the countryside, and turn compartments into isolated crime scenes. Accidents were frequent and gruesome. Similar fears attached to steamships and early automobiles (“devil wagons”). Cars later caused tens of millions of deaths, plus pollution and urban redesign around the machine.

Nuclear fission and fusion (1940s onward)

Before the Trinity test, Manhattan Project scientists calculated whether a fission explosion might ignite the atmosphere or oceans in a runaway fusion reaction. Some feared it would “draw the final curtain on mankind.” Later worries included cobalt bombs that would irradiate the planet for years, nuclear winter, and simple overkill from tens of thousands of warheads. The atmospheric-ignition risk was ruled out by further calculation; the other risks remain real even if they have not (yet) ended civilization.

Recombinant DNA / genetic engineering (1970s)

Scientists themselves called a moratorium and convened the 1975 Asilomar conference because they feared engineered microbes could escape and cause novel epidemics, “epidemic cancer,” or irreversible ecological change. Popular imagery invoked The Andromeda Strain. Guidelines were written; the most lurid scenarios did not occur, but the debate prefigured later fights over GMOs and synthetic biology.

Nanotechnology and “grey goo” (1980s–2000s)

Eric Drexler’s 1986 book Engines of Creation described self-replicating molecular assemblers that could, in principle, consume the biosphere and turn it into “grey goo.” Bill Joy’s 2000 Wired essay “Why the Future Doesn’t Need Us” amplified the warning. Prince Charles asked the Royal Society to investigate. Drexler later said he regretted popularizing the phrase and argued the accidental-runaway version was unnecessary and unlikely; the more realistic concern became deliberate misuse.

Other recurring themes

• Mass media (novels, radio, television, later the internet and social platforms): brain-rotting passivity, moral corruption, violence, isolation, or political fragmentation.
• Overpopulation enabled by agricultural and medical technology: Paul Ehrlich’s The Population Bomb (1968) predicted mass famine in the 1970s–80s.

[and the subsequent extension - Global Warming...]

• Unintended chemical side-effects: Thomas Midgley’s tetraethyl lead and CFCs produced widespread poisoning and ozone depletion rather than the intended convenience.
• Computers and AI: From Alan Turing’s 1951 remark that machines would “take control,” through Y2K collapse fears, to present-day arguments that misaligned superintelligence could be an existential risk.

The historical record shows both over-prediction of doom and under-prediction of certain harms (traffic deaths, industrial accidents, environmental damage, weapons proliferation). Technologies that actually threatened large-scale destruction—nuclear weapons being the clearest case—prompted arms-control efforts, safety cultures, and near-misses rather than the automatic extinction some expected. The same cycle of alarm, regulation, adaptation, and leftover genuine risk is visible today around AI, synthetic biology, and other dual-use fields.