Human use of fossil fuels is altering the chemistry of the atmosphere; oceans are polluted and depleted of fish; 80 per cent of Earth's forests are heavily impacted or gone yet their destruction continues. An estimated 50,000 species are driven to extinction each year. We dump millions of tonnes of chemicals, most untested for their biological effects, and many highly toxic, into air, water and soil. We have created an ecological holocaust. Our very health and survival are at stake, yet we act as if we have plenty of time to respond.

One of the joys of being a grandparent is getting to see the world again through the eyes of a child.

With the world's human population now at seven billion and growing, and the demand for technology and modern conveniences increasing, we can't control all our negative impacts. But we have to find better ways to live within the limits nature and its cycles impose.

Other things, like capitalism, free enterprise, the economy, currency, the market, are not forces of nature, we invented them. They are not immutable and we can change them.

What permaculturists are doing is the most important activity that any group is doing on the planet. We don't know what details of a truly sustainable future are going to be like, but we need options, we need people experimenting in all kinds of ways and permaculturists are one of the critical gangs that are doing that.

I can't imagine anything more important than air, water, soil, energy and biodiversity. These are the things that keep us alive.

Planting native species in our gardens and communities is increasingly important, because indigenous insects, birds and wildlife rely on them. Over thousands, and sometimes millions, of years they have co-evolved to live in local climate and soil conditions.