The grim truth is that the rich are able to live as they do only because others are poor: there is neither the physical nor ecological space for everyone to pursue private luxury.

On my first night at boarding school, I felt entirely alone. I was shocked, frightened and intensely homesick, but I soon discovered that expressing these emotions, instead of bringing help and consolation, attracted a gloating, predatory fascination.

What you see is not what others see. We inhabit parallel worlds of perception, bounded by our interests and experience. What is obvious to some is invisible to others.

After my cancer diagnosis this year, I was offered a choice of treatments. I wanted to make an informed decision. This meant reading scientific papers. Had I not used the stolen material provided by Sci-Hub, it would have cost me thousands.

There is a tension between parliamentary and popular sovereignty. A lively, meaningful democracy would achieve a balance between the two.

Few people younger than me know that it was once normal to see fields white with mushrooms, or rivers black with eels at the autumn equinox, or that every patch of nettles was once reamed by caterpillars.

I do not want to abandon representative democracy. I want to see it balanced by popular sovereignty, especially the variety known as deliberative democracy.

Like coal, capitalism has brought many benefits. But, like coal, it now causes more harm than good.

If our grazing land was allowed to revert to natural ecosystems, and the land currently used to grow feed for livestock was used for grains, beans, fruit, nuts and vegetables for humans, this switch would allow the UK to absorb an astonishing quantity of carbon.

We can expect commercial enterprises to attempt whatever lawful ruses they can pull off. It is up to society, represented by government, to stop them, through the kind of regulation that has so far been lacking.

I believe resilience is the most useful human quality, and I've sought to cultivate it, but in 2019 I felt my resolve begin to weaken at times as it has never done before.

While arguments rage about plant- versus meat-based diets, new technologies will soon make them irrelevant. Before long, most of our food will come neither from animals nor plants, but from unicellular life.

New roads carve up the countryside, dispelling peace, creating a penumbra of noise, pollution and ugliness. Their effects spread for many miles.

There are, I believe, three steps to overcoming fear: name it, normalise it, socialise it.

Places that have become agricultural deserts, trashed by giant corporations, could be reforested, drawing carbon dioxide from the air on a vast scale. The ecosystems of land and sea could recover, not just in pockets but across great tracts of the planet.

One-planet living means not only seeking to reduce our own consumption, but also mobilising against the system that promotes the great tide of junk. This means fighting corporate power, changing political outcomes and challenging the growth-based, world-consuming system we call capitalism.

Rainforests are not confined to the tropics: a good definition is forest wet enough to support epiphytes - plants that grow on other plants. Particularly in the west of Britain, where tiny fragments persist, you can find trees covered in rich growths of a fern called polypody, mosses and lichens, and flowering plants climbing the lower trunks.

Never underestimate the power of intrinsic values. They inspire every struggle for a better world.

Emotionally damaged men all too often rip apart their own lives, and those of their partners and children. I see both physical fitness and emotional strength as virtues, but they are acquired by entirely different means.

Surplus money allows some people to exercise inordinate power over others: in the workplace; in politics; and above all in the capture, use and destruction of the planet's natural wealth.

Representative democracy is a remarkably blunt instrument. Hundreds of issues are bundled together at every election, yet the vote tends to swing on just one or two of them.

If commercial fishing were excluded from large areas of the sea, the total catch would be likely, paradoxically, to rise, due to what biologists call the spillover effect.

If you construct political narratives around the psychodramas of politicians, even when they don't invite it, you open the way for those who can play this game more effectively.

After 12,000 years of feeding humankind, all farming except fruit and veg production is likely to be replaced by ferming: brewing microbes through precision fermentation.

As SUVs are higher and heavier, they are more likely to kill the people they hit. Driving an SUV in an urban area is an antisocial act.

If you or I had lived 500 years ago, our worldview, and the decisions we made as a result, would have been utterly different. Our minds are shaped by our social environment, in particular the belief systems projected by those in power: monarchs, aristocrats and theologians then; corporations, billionaires and the media today.

As some of us can testify, the viciousness of the lobby groups funded by the fossil fuel industry, and the publications that amplify their message, knows no limits. As we have already seen, they treat even children as fair game.

I might find myself standing, transfixed, by the roadside, watching a sparrowhawk hunting among the bushes, astonished that other people could ignore it. But they might just as well be wondering how I could have failed to notice the new V6 Pentastar Sahara that just drove past.

I became an environmentalist because I love the living world, but I spend much of my life thinking about electricity, industrial processes and civil engineering.

A large body of literature suggests that wellbeing is intimately linked to attachment - not only to other people, but also to the natural world.

For many years, wildlife film-making has presented a pristine living world. It has created an impression of security and abundance, even in places afflicted by cascading ecological collapse.

Pedestrians and cyclists are squeezed by planners into narrow and often dangerous spaces - the afterthoughts of urban design.

Food production is ripping the living world apart. Fishing and farming are, by a long way, the greatest cause of extinction and loss of the diversity and abundance of wildlife. Farming is a major cause of climate breakdown, the biggest cause of river pollution and a hefty source of air pollution.

Public figures talk and act as if environmental change will be linear and gradual. But the Earth's systems are highly complex, and complex systems do not respond to pressure in linear ways.

The notions that nature exists to serve us; that its value consists of the instrumental benefits we can extract; that this value can be measured in cash terms; and that what can't be measured does not matter, have proved lethal to the rest of life on Earth.

Immense wealth translates automatically into immense environmental impacts, regardless of the intentions of those who possess it.

We have a wider political and economic system in which ancient, landed power still carries immense weight. There is nothing some landowners would like more than to set the police on those who dare to venture into their vast estates.

David Cameron's government criminalised squatting in empty homes. This too was previously a civil matter. Thousands of homeless people found themselves on the wrong side of the law. Some have been imprisoned for using property abandoned by its owners.

History shows that attacks on general freedoms often begin with an attack on the freedom of a minority. It teaches us that we should never allow a government to divide and rule. An attack on one is an attack on all.

Rather than allowing Roma, Travellers and homeless people to be picked off, all those of us who fear the criminalisation of trespass should join forces with them, protecting their rights while we defend our own.

Farmfree production promises a far more stable and reliable food supply that can be grown anywhere, even in countries without farmland. It could be crucial to ending world hunger.

I have tried to keep my eco-anxiety at bay, to box it into my working life. But every month this becomes more difficult. The rising sense of panic I feel is entirely rational; we should all be feeling it. But we can't live with it through every hour of every day.

When I kayak in Cardigan Bay, in Wales, what I hope to find above all else is dolphins. Sometimes I do, and these days are the waymarks of my life.

If we stop dragging trawls and dredges through it, the life of the seas would recover with astonishing speed. Because most marine animals are highly mobile during at least one stage of their development, the rewilding of the seas needs little help from humans.

We are often told that curtailing the freedom of business is coercive and undemocratic. But by what democratic principle should corporations and billionaires decide the fate of current and future generations? When a government releases them from regulation, it allows them to determine whether other people live or die.

The justification for early boarding is based on a massive but common misconception. Because physical hardship in childhood makes you physically tough, the founders of the system believed that emotional hardship must make you emotionally tough. It does the opposite.

When expressions of emotion are dangerous, and when you are constantly told that this terrible thing is being done for your own good, you quickly learn to hide your true feelings, even from yourself.

I could see the point of Brexit if it meant returning power to the people.

We urgently need more trees, but we appear to believe that the only means of restoring them is planting. We have a national obsession with tree planting, which is in danger of becoming as tokenistic as bamboo toothbrushes and cotton tote bags.

We should continue to mobilise against the destruction of the world's great habitats, and its terrifying implications. But the most persuasive argument we can make is to show we mean it, by restoring our own lost wonders.