If you were the only living being left on the Earth, how long do you think you would last?

It would depend on the conditions - mainly weather and place.

If it were right here at home with the same weather cycles as now, I could last for quite a while growing vegetables from seed, carting water from the dam, boiling it on fires of deadwood. Most of my tools could last a natural life span.

I'd cease to worry about weeds (except for Crofton) and farm maintenance, and would trust to nature to find its own new balance in evolution. The solar power system would not last long after the batteries ran out. There'd be no fuel for transport. My world of experience would shrink to how far I could travel on horseback or on foot.

If it was safe I'd still take long walks in nature. If there was grass I'd keep and ride the horses for as long as nature allowed. That would be 9 months to 2 years before the sub-tropical grasses leached so much calcium from their bones that they died of osteoporosis.

My poor cat would have to learn how to hunt for herself. Since she's desexed, her predations would end with her. Since there'd be no sources of anti-tick poison, she'd soon die of paralysis.

I'm fairly introverted. When Ari was on performance tour in Europe for three months, I found it took me six weeks before I felt the urge to reach out and visit friends.

But I know that eventually the lack of purpose and the lack of contact with people I love would wear me down. If I still had my library, I might keep reading literature so that I'd have some ersatz sense of the former peoples of the world and their situations and relationships. I might even continue writing just for myself.

There was a time when I first discovered the high probability of global catastrophic extinction. It was about six years ago. At first, I went into shock, then terrible grief and depression (which has remained not far below the surface ever since), then planning a space-age time-capsule to record the follies that lead to destruction, and finally this bleak acceptance - in which my only "purpose" is eco-writing - and the feeling is one of utter futility.

At some point, one good thought dawned on me - that it no longer matters that I never achieved anything worthwhile. For with global extinction, there is no one left to appreciate or care. All the things that ever mattered dissolve into the eons of the universe, a rubble of atoms.

I don't know if I would have enough self-discipline to maintain meditation and sanity.

Suicidal ideations have been a broken record in my head since I was eight years old. I've learned to recognise them as mechanical, automatic, habitual - not meaningful. Viewing them this way robs them of their power to inject adrenaline into my blood. Adrenaline is the poison that throws me into self-inflicted PTSD type stress and catapults me down into the abyss. Disempowering the thoughts keeps me afloat on the surface of life.

If ever there was a situation in which I was the last human alive - I can't really be sure whether I would take the easy way out (cease eating and drinking - death in three days) or whether I would do what was necessary to stay alive, out of a kind of curiosity to see how it finally ends. Either way, I think, would take tremendous courage - and I am not a very courageous person.