Letters archive

You call for clear-headed assessment of schemes to reduce our impact on the natural world (Leader, 18 January ). We also need a new unit for a new measure of the environmental cost to the planet of a person in a year. The point would be to allow us to compare individuals: people who have …

Thank you for reporting your experiment with going vegan ( 4 January, p 32 ). I suspect one of the main issues that puts people off trying this is that basic nutrition and cooking skills are no longer taught a lot in UK schools. This is a reason, alongside time limitations, for people falling back …

Sam Edge suggests that the only way to rule out whether computers could have consciousness as we would experience it, is to fall back on dualism – which, he says, is a faith-based belief, not amenable to any scientific enquiry (Letters, 4 January ). A dualistic approach isn't necessarily either faith-based or unscientific. And it …

What can the aviation industry do to reduce emissions? One way to significantly cut carbon dioxide per passenger is to reduce the number of premium seats per plane ( 11 January, p 18 ). On long-haul flights, each first class seat takes about five times as much cabin area as an economy seat, and a …

  • The eruption of the Taal volcano in the Philippines isn't yet large enough to produce measurable global cooling (18 January, p 5). • Braden Tierney and colleagues looked at 13 conditions and found that a person's microbiome was a better predictor of 12 of them than their genetics ( 18 January, p 6 …

I appreciate Tom Crowther's research on reforestation, which is vital and urgent ( 11 January, p 44 ). But reforestation is a stopgap solution to climate change while we decarbonise the economy. What if we plant enough trees to stabilise carbon dioxide levels in the air, while still burning fossil fuels? We would end up …

Will motion sickness be an issue for people deprived of a sense of control in autonomous cars, asks Frank Siegrist (Letters, 18 January ). It will. I first heard of this in 2018, at a conference on highly automated vehicles at the University of Warwick, UK. Before we reach full vehicle autonomy, human drivers will …

You report philosopher Krist Vaesen arguing that Neanderthals were such a small population that they may have been intrinsically at risk of extinction through a combination of unfortunate circumstances, rather than being actively exterminated or out-competed by Homo sapiens ( 7 December 2019, p 19 ). Researchers could also, given the small size of the …

Chandra Prescod-Weinstein asks: are dark matter and dark energy related? Yes: both are imaginary constructs required to paper over the cracks in the "big bang" concept ( 4 January, p 20 ). I find it difficult, as an old physicist, to understand how far this illusion has gone within the physics community. I remember the …

• Our comment on George Monbiot's statement that the "land efficiency" of Solar Foods protein production from hydrogen and oxygen is roughly 20,000 times that of conventional agriculture, based on the area occupied by the factory, is only that it isn't relevant: he also uses Solar Foods' figure that the area of the factory, plus …