Climate war
The US Department of Defense (DoD) report calling on all of us to work together to combat the threat of climate change is a welcome departure from previous secret policies (18 October, p 6).
This openness is a good sign amid preparation for the crucial UN Climate Change Conference (.
There is no time to lose in encouraging the DoD (and all military powers) to participate fully in the efforts to secure a genuine binding commitment from all developed and developing nations to restrict the emissions of greenhouse gases.
The gross unfairness of present international discussions is that, despite the massive persisting emissions of militaries all around the world, it is only civilian communities and taxpayers who are being asked to pay for the consequences.
Sunbury-on-Thames, Surrey, UK
Climate war
It was encouraging to read that the US military is starting to wake up to the threat of climate change. But in typical military fashion, the responses you reported were mostly addressing the symptoms of climate change, with a view to maintaining their capacity for business (or warfare) as usual.
How might the situation look if the threat became serious enough for the military to start addressing the causes of climate change? Would we see missile strikes on major carbon emitters, such as coal-fired power stations or oil rigs; drones carrying out targeted assassinations of fossil-fuel company CEOs; the full force of surveillance and espionage focused on disrupting the carbon trade; covert financial support for organisations supporting green lifestyles?
I think on balance I’d rather it was the politicians who came up with something worthwhile at the forthcoming talks.
Matlock, Derbyshire, UK
Fuel for thought
In considering how economies could have arisen without fossil fuels, Michael Le Page underestimates the large role played over the past 300 years by steel (18 October, p 34).
Without the economic surplus from fossil fuel use since the Industrial Revolution, as a resident of the lower Thames, UK, I would probably now be carving driftwood or herding cattle, not holding the job title Thought Director.
Today’s cities are essentially purpose-built mountains of steel and concrete. Mass steel production without coke or cheap coal-fuelled electricity is virtually inconceivable.
Indeed the price structures of a fossil-free economy would be quite different from today’s. Full-blown capitalism would probably not have developed. Power would not be used for lighting, but potentially for manufacturing by a centralised authority.
Moving from the counter-factual to the next 50 years, the critical issue is: how do we socially restructure our cities to use 90 per cent less power?
London, UK
Fuel for thought
In addition to our massive reliance on fossil fuels as an energy source, there is another aspect that is mentioned in your article but not explored.
Fossil fuels, and particularly oil, are an essential feedstock for the chemical industry. The first synthetic dyes depended on precursors derived from coal.
Nowadays, petrochemical-derived products are essential for practically all synthetic chemistry, from polymers to pharmaceuticals. There is no serious prospect of replacing oil as the main feedstock, despite the heroic efforts in industry and academia.
As an indicator of the relative value of petrochemicals and fuel, in the 1960s Imperial Chemical Industries had a retail business in petrol under the ICI brand. The petrol supplied to the filling stations was a waste product from ICI’s refinery at Billingham.
Great Shelford, Cambridge, UK
Fuel for thought
Michael Le Page writes that airships would depend on hydrogen, because “helium is derived from natural gas”.
Current helium storage is strongly associated with natural gas technology, it is true. However, this is largely because of the presence of geological trapping structures, where the gas is caught and naturally concentrated.
Even without the development of drilling technology, the salt movements that generate these traps would still happen, and would accumulate helium. Detecting and exploiting it is another question, however.
Aberdeen, UK
Good health for all
Harvey Rubin and Nicholas Saidel point out that inadequate organisation of health services around the world could come back to bite us, possibly through Ebola or a more infectious future microorganism (25 October, p 26).
There is a good analogy in history. In Victorian Britain, urban slums were not only eyesores and terrible places for the poor to live, but they were also incubators of infectious diseases that were easily carried out to their more salubrious surroundings.
As successive governments in the 20th century provided more housing and gradually allowed their residents greater economic power, the health of the whole nation was able to improve.
So it is with world health now: we richer countries need to invest substantially in both health and living conditions for all, not only for sentimental reasons but also to protect ourselves.
Moordown, Dorset, UK
A month of Sundays
In his list of revolutionary human ideas, Colin Barras includes lunar calendars, implying these allowed people to plan for seasonal events (25 October, p 32).
But the lunar calendar is not much good for this. It has an error of plus-or-minus 15 days compared with the seasons, and you have to calibrate it by adding a 13th month every two or three years.
A better way of keeping track of the seasons is simply to observe where the sun rises 鈥� and ignore the moon.
Les Essarts-le-Roi, France
Life or death
Clare Wilson opens her article on trapping cancer cells in the body with a statement implying that death is the worst possible outcome for those with the disease (27 September, p 39). Having seen the suffering experienced by family members and friends with cancer and discussed their feelings with them, this is plainly wrong.
A quick, pain-free death would be for many people far preferable to months or years of debilitating illness either through the cancer itself, or attempts at treatment.
Death is not necessarily something to be feared and avoided at any cost; some things are worse.
Cawarral, Queensland, Australia
Life or death
鈥� Considering good palliative care over gruelling treatment is an important issue in healthcare, and one explored by surgeon Atul Gawande in our recent interview (18 October, p 30).
Against the tide
Michael Slezak calls attention to the difficulty Polynesian groups would have encountered sailing eastwards across the Pacific, against the south-east trade wind (4 October, p 12).
This difficulty is well illustrated by the sufferings of the crew of the Nantucket whale ship Essex, which was holed by a sperm whale and sank in the mid-Pacific in November 1820.
The crew had time to provision three of the whaling boats with fresh water, food and navigational instruments. Their best hope of reaching land would have been to head west towards the Marquesas Islands or Tahiti, but the crew mistakenly believed that the islanders were cannibals, so they chose instead to sail east for Chile.
They had a terrible journey: one of the three boats was lost with all hands while the other two ran out of food and water.
They took three months to cover 4800 kilometres and only eight of the 20 crew survived; some of these had been reduced to cannibalism of their deceased shipmates.
The events that befell the crew would later inspire Herman Melville to write Moby-Dick.
Sheffield, UK
Lot of Tosh
In discussing how to deliver electricity to the world without sending carbon emissions soaring, Fred Pearce writes that “the test case is rural India” (25 October, p 12).
From my experience of rural India I would say that this is not a representative case. The parts that have recently been connected to the grid have perhaps the most unreliable electricity in the world.
India, even in big cities, has several power cuts every day. The power supply in rural areas is so bad that villages can go days without power.
Tosh village is a few kilometres from one of India’s newest hydroelectric dams at Pulga. It was granted “free electricity” when he officially opened the plant 鈥� years ahead of its actual completion 鈥� in 2009.
Since then, Tosh villagers have not had to pay for power, but most nights, when they need electricity most, it is cut. Because the supply is so unreliable, few invest in appliances for heating or cooking, using wood-fired stoves instead, which harm the environment much more than the generation and transmission of electricity would. If the electricity supply was reliable, I am sure that more families would make the switch away from these methods.
Tadworth, Surrey, UK
Flights of fancy
Should personal air vehicles ever become anything more than a rich person’s toy (25 October, p 19), which I very much doubt, I do not understand why anybody would claim them as a solution to road congestion, except to sell the idea to government.
As road building in the UK demonstrates, increased capacity only relieves congestion in the short term. Having spent millions widening the motorway orbiting London to eight lanes and more, the level of congestion is again back where it was at six lanes.
Stotfold, Bedfordshire, UK
Body canvas
In Catherine Brahic’s article on the oldest hand stencil yet discovered, dating from 40,000 years ago, Paul Pettitt speculates that early humans may have realised that they could represent three dimensional objects using two dimensional outlines (11 October, p 10).
Two issues later, Colin Barras identifies the significance of cosmetics in human development, with the earliest evidence for this being 100,000-year-old ochre pigments (25 October, p 32).
I have seen numerous documentary videos of modern hunter-gatherers applying pigments to their bodies by spraying them either directly from their mouths or from a straw. It is easy to imagine how someone in prehistoric times might have placed their hand on a flat surface to apply body paint, and noticed the pattern left on the surface afterwards, leading to the making of hand stencils and then to drawing outlines.
It’s possible that human figurative art derives from our desire to decorate our bodies.
St Albans, Hertfordshire, UK
Calculated question
Mike Belton asks “if you could find out anything you wanted to know by typing a question into a page on the internet, would there be any meaning to our lives any more?” (25 October, p 31).
I put this question to my computer. It hasn’t completed its investigations yet, but I suspect it will ultimately decide the answer is 42.
More seriously, it is the fact that we can debate such questions and the internet can’t which makes us humans distinguishable from computers. Information is important, but it isn’t everything.
Allendale, Northumberland, UK
For the record
鈥� In our article on disrupting the blood-brain barrier, the area stimulated by ultrasound measured 1 by 5 centimetres (22 October, p 14).
鈥� The rule of law fell short in our article on human innovation (25 October, p 32). The earliest recorded legal codes that we know of date from 4400 years ago.