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 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.
The high seas - in other words, the oceans beyond the 200-mile national limits - are a lawless realm.
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.
For some of Britain's most powerful people, hunting and shooting are primordial rights, and any challenge to them is treated as illegitimate. They assert ownership not only of the land but also of the social relationships surrounding it.
There is plenty of housing - for the rich. But a series of outrageous policies ensure that it remains inaccessible to the poor.
In thinking about male identities, I'm struck by the inadequacy of the terms we use. The notion that men should be distant, domineering and self-seeking is often described as toxic masculinity, but this serves only to alienate those who might need most help.
Economic growth is the aggregate effect of the quest to accumulate capital and extract profit. Capitalism collapses without growth, yet perpetual growth on a finite planet leads inexorably to environmental calamity.
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.
It doesn't matter how many solar panels you install if you don't simultaneously shut down coal and gas burners.
Landowners, farmers and gamekeepers, though they comprise a small minority of the rural population, claim to speak for everyone, and dismiss those who challenge them as interfering urbanites.
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.
While some livestock farms are much better than others, there are none in this country that look like natural ecosystems. Nature has no fences.
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.
Even when political reporting is not reduced to personality, political photography is. An article might offer depth and complexity, but is illustrated with a photo of one of the 10 politicians whose picture must be attached to every news story.
As the scale of economic activity increases until capitalism affects everything, from the atmosphere to the deep ocean floor, the entire planet becomes a sacrifice zone: we all inhabit the periphery of the profit-making machine.
I have lived long enough to witness the vanishing of wild mammals, butterflies, mayflies, songbirds and fish that I once feared my grandchildren would not experience: it has all happened faster than even the pessimists predicted.
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.
If I could turn back the clock, magically deleting my prostate cancer, the surgery I needed and its complications, would I do so? It seems an odd question. But I find it surprisingly hard to answer.
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.