Letters archive

Your article "A new energy world" floats a potential solution to intermittent renewables: continental-wide power grids ( 7 August, p 34 ). This is a fantasy in the current and likely future world we live in. One of the primary responsibilities of a country to its citizens is the security of power supply and this …

It is a tragedy that the public won't support taxation of hydrocarbon fuels to a level that reflects the damage that vehicles and home heating systems do to the environment. It is absurd that for many trips, private cars are still more economical than trains, even when a car has no passengers. However, there is …

Capturing carbon from the air to make jet fuel isn't carbon negative. Burning the fuel will release all the carbon dioxide back into the atmosphere. It is, at best, carbon neutral, but in reality will have inefficiencies that will need to be offset by additional carbon capture and storage. We need to do this, but …

The graph on page 38 didn't feature renewables that were used in 1800. At that time, wind energy was used for fishing, merchant shipping, travel, food production and household tasks such as drying clothes, yet it is rated nil on the graph. Likewise, hydropower turned mill wheels and solar power was used for food preservation. …

Richard Jones suggests that it would be better if we don't try to spread ourselves across the galaxy because of our tendency to greed and crime ( Letters, 7 August ). We are, like all other life on Earth, the product of evolution and many of our more negative behaviours have helped us to survive …

The question of what came first – cells or cell membranes – is asked yet again in your report on a method to create membranes using a set of relatively basic starting materials ( 14 August, p 19 ). Perhaps the question is redundant. The proposal that life began in alkaline hydrothermal vents doesn't require …

Whales and dolphins already have enough difficulty communicating because of pervasive human-generated marine noise ( 7 August, p 15 ). Now we learn that humans are going to make life more difficult for them by transmitting their clicks and whistles to hide secret underwater messages. I imagine that for cetaceans it will be akin to …

There is a general view that the cost of saving the planet using machines to suck carbon out of the air, known as direct air capture (DAC) technology, will be prohibitive ( 21 August, p 41 ). But consider these figures. A London to New York flight is about 5500 kilometres, producing about 91 tonnes …

Your latest round-up of covid-19 vaccines was useful and thorough, and more detailed than most accounts ( 14 August, p 8 ). You mentioned other vaccines that the UK government has supported, but which haven't yet come to fruition – those from CureVac, Valneva and Novavax. This got me wondering why these and others still …

You report that Machu Picchu has been declared 20 years older than we thought (14 August, p 23). Considering it was built on top of a mountain with no builders' merchants and no power tools, it probably took well over 20 years to complete. This variability in its age seems like no big deal.