Letters archive

I thoroughly enjoyed reading your feature on the 2000-watt energy-saving challenge( 11 February, p 36 ). We now need something similar for water consumption. There are few tools to track usage and not that much talk about it. Shouldn't we give water use the attention it deserves, or, like energy, are we going to leave …

I find it amazing that it has taken China and the US until now to think of spying on each other using flying objects. I suggest the outrage may be manufactured for immediate political ends( 11 February, p 9 ).

Was the shift to farming really the worst mistake in human history, asks Michael Marshall, concluding that the claim is at best an exaggeration. I would go further, drawing on relevant points made by the researcher Jacob Bronowski( 25 February, p 28 ). You can't civilise on the move. No group of humans has ever …

To argue that a focus on negative emission technologies (NETs) is slowing the fight against climate change is to fall into a common trap. A look at plans drawn up to meet the goals of the Paris Agreement will tell readers that NETs are a baked-in requirement for meeting the 1.5°C pathway( 18 February, p …

Surely, every time we find a new source of normal matter, this decreases the amount of dark matter we must hypothesise to explain the behaviour of galaxies( 11 February, p 46 ). One recent example is the discovery that there are far more red dwarfs than we thought. There are other candidates, too. How about …

We know that one form of energy without matter is the photon. Could it follow that gravity without matter is the graviton? Could free gravitons, still exerting a pull, explain the gravitational effects of dark matter?

One day, I hope to be able to have a "Future Home" of my own and reap the energy-saving benefits. However, houses are built to last, so the vast majority of homes won't be replaced soon. Green technology has to make its way into current homes, with better incentives to retrofit, replacing energy and carbon-intensive …

I passionately support your campaign, together with the i newspaper, to highlight the state of the UK's rivers( Leader, 18 February ). Their current deplorable condition is surely down to the years, if not decades, of chronic underinvestment. For example, the UK government has left the Environment Agency without adequate resources to inspect and monitor …

It was always going to be a big ask to remove sufficient ticks from a semi-forested US area to truly affect Lyme disease rates for people. And yet, the rate of disease among pets did fall significantly. One possible explanation might be the fact that there is a vaccine for pets, but not people( 18 …

Your 2000-watt challenge article seems overly pessimistic about the difficulty of cutting energy use. We run our research station, with 12 buildings, on around 14 kilowatt-hours a day, generated by a solar power system with a battery backup. We have lighting, fans, dehumidifiers, power tools, a plethora of lab equipment and a good, basic washing …