Grappling with the mysteries of early Earth (1)
In your look at when oceans, land and life emerged on Earth, the debate over where Earth’s water came from was raised (13 August, p 46).
Another planet, Theia, is thought to have struck the infant Earth, perhaps after coming from the outer solar system, which is the source of icy comets, to orbit the sun ahead or behind our planet. Eventually, maybe due to perturbations from Venus and Jupiter, Theia is thought to have collided slowly with Earth, almost melting it and creating the moon from debris blasted into orbit.
If Theia was rocky and covered in a thick layer of water ice, this impact would have allowed most of its ice to be ejected into orbit while its core coalesced with Earth. Ice and water in orbit would have been chilled and eventually swept up by Earth.
The atmosphere would then have contained a large volume of turbulent water vapour, radiating heat into space while simultaneously reflecting more of the early sun’s radiation. This would result in more rapid cooling of the planet’s surface at an earlier stage.
Grappling with the mysteries of early Earth (2)
When proto-Earth was struck by Theia, I assume its orbital parameters were altered. Is anyone looking into the scale of such a change? Could it have brought the combined bodies into the habitable zone?
On the subject of noise, let's talk about sirens
Your cover story “Shhhhh…” draws attention to health problems aggravated by loud or unexpected noise (13 August, p 38). I believe the contribution of emergency vehicle sirens to anxiety, depression and other conditions is ignored due to their multifactorial origins.
A fruitful research area, now that most vehicles contain sophisticated electronics, would be to look into more subtle and focused ways of warning people of approaching emergency vehicles.
Could we tap old mines as a new source of water?
I have reservations about large reservoir development to address water shortages, as it invariably disrupts communities and may reduce available farmland (Leader, 13 August).
There are vast water reserves in old mine workings. If coal is now redundant as an acceptable fuel, then we could repurpose mine galleries, tunnels and shafts that hold significant amounts of water. Using it would entail purification and decontamination, but that takes place with even the most pristine of surface reservoirs.
Problem is, our thirst for energy is unstoppable
Eugene Linden suggests drilling with millimetre-wave beams to access deep geothermal heat, a supply of energy that isn’t liable to the intermittency that affects wind and solar (13 August, p 25). So, problem solved?
Sadly, such advances would do little to remove the problem of our constant growth in energy use. US figures show 2.9 per cent compound annual growth from 1650 to 2009. The blog details how, unchecked, our increasing demand results in the entire energy of the sun being required in 1400 years.
At best, geothermal energy could provide an alternative that enables us to stop using fossil fuels, but it isn’t a total solution in the sense of allowing human civilisation to endure long term.
Only way forward is to keep new coal in ground
Richard Mellish makes a logical argument for the opening of a new coal mine in Cumbria (Letters, 13 August). However, he has overlooked the law of supply and demand. If there is an extra supply of coal, the price will fall and more will be used. His argument would be valid if the opening of a Cumbrian mine caused a mine somewhere else to close. However, it won’t.
The only way to reduce fossil fuel use is to stop opening more mines and oil wells.
Mind your language to advance climate cause
Bill McGuire talks of the need for a public information campaign about the climate emergency to educate people and trigger action (6 August, p 29). He is absolutely right, but we need so much more.
I watched a TV weather forecast during the recent heatwaves that talked of the “beautiful” weekend ahead and “perfect BBQ weather”. An announcement I heard on public transport finished with “enjoy the weekend, it’s gonna be another gorgeous one”.
Climate change is neither beautiful nor gorgeous, it is catastrophic. Language matters. It is up to all of us to change the narrative. Government needs to play its part, the rest of us do too.
Not immoral? The fossil fuel industry?
I was amazed to see a letter claiming fossil fuel production was neither illegal nor immoral (Letters, 16 July). Really? The oil and gas industry has known for decades that its activities aren’t just heating Earth, but causing devastating pollution and leading to a planet that will be uninhabitable.
Knowingly contributing to the possible extinction of human and other life on Earth would seem to me, and I imagine most people, the very definition of immoral.
Rumours of AI's death are exaggerated
David Hodgson fears that “terminating” a sentient AI could be seen as murder (Letters, 6 August). Switching off a computer program, no matter how complex, is reversible provided its state has been written to persistent storage. A murder trial might struggle to convict if the defence can call the victim to the stand.
Living green on energy drinks and fizzy pop
Thank you for the article on the environmental impacts of various foods and drinks (13 August, p 13). As a result of reading it, I have resolved to do my part for the environment by living on Red Bull and Coke.
For the record {27 Auguest 2022}
The crater lakes shown on S茫o Miguel in the Azores are volcanic, rather than the result of impacts (6 August, p 45).