Happy hormones | Fuel costs | Drive-in parking | Guys and girls | Young or old? | Singapore pollution

Re your report (‘Pull the plug’: protesters resort to direct action against AI firms, 6 October), the US neuroscientist Ben Rein has shown that there is a fundamental difference in our cognitive response according to the type of interaction we have. In-person meetings and conversations show a dramatic increase in serotonin, oxytocin and dopamine – “feelgood” hormones – compared with online interactions. I have been encouraged to speak to people at bus stops.
Judith Furner
Eastbourne, East Sussex

• Re easing winter fuel costs (Report, 6 October), it would benefit everyone if the outrageous daily standing charges were reduced or on a sliding scale based on usage. I can’t be the only person whose standing charges each month are half or more than the energy used.
Judith Pearson
Sheffield

This is no scoffing matter. The accelerating proliferation of advanced nuclear weapons is bringing ‘end times’ closer by the day

Humankind has fearfully and sometimes joyfully anticipated the end of the world ever since it began. The Bible’s Book of Revelation speaks of “end times”, a period of tribulation, war, famine, plague, floods and environmental catastrophe that may seem a less absurd prospect today than perhaps it once did. Islam, too, posits a fateful day of judgment or day of reckoning. Christian evangelicals believe that, in the final rapture, a chosen few – the righteous or the “elect” – will be saved while sinners burn. It’s a minority view. Matthew’s gospel predicts most people will defy, ignore or ridicule warnings of imminent Armageddon. Peter, another of Jesus’s disciples, agreed: “In the last days, scoffers will come, scoffing and following their own evil desires.” Yet such worldly scepticism does not mean a universal cataclysm is less likely. It may make it more probable.

Donald Trump’s blanket denials of the dangers ostensibly posed by artificial intelligence, whose uncontrolled development is seen by some as the latest harbinger of apocalypse, could be interpreted as fulfilling Peter’s prophecy. This US president, the nearest thing the world has to a one-man doomsday machine, is a great one for scoffing and evil desires. In Robert Harris’s 2019 novel, The Second Sleep, a worried scientist lists half a dozen ways the world might end. They include devastating climate change, pandemic disease, a giant asteroid collision with Earth, or some other overwhelming calamity. Few heed the fictional scientist’s fears. In the event, what destroys him and almost everybody else is a disturbingly plausible cyber crash – a global digital and internet meltdown.

Simon Tisdall is a Guardian foreign affairs commentator

Newly established commission identifies 17 catastrophic threats to human health but says ‘realistic route to act’ on each exists

Humans could become extinct by the year 2100 due to malicious use of AI or nuclear conflict, according to a new global risk assessment.

They top a list of 17 major threats to human health over the next 75 years, which also includes cuts to aid spending by wealthy countries, the climate crisis and childhood malnutrition.