Thanks to evolution, our bodies have powerful ways to ward off illness and infection and enable us to live long and healthy lives. Why, then, do health costs continue to climb at unsustainable and frightening rates?

Our choices at all levels-individual, community, corporate and government-affect nature. And they affect us.

Rapid population growth and technological innovation, combined with our lack of understanding about how the natural systems of which we are a part work, have created a mess.

So now the challenge is to imagine a different world where our wealth is in human relations and the things we do together, and we learn to live in balance with the rest of nature.

The terrible part of this looming catastrophe is that people have been working on solutions for years and have developed concrete steps to massively reduce our energy use, while stimulating whole new industries and technologies that are more efficient and affordable.

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.

Global trade has advantages. For starters, it allows those of us who live through winter to eat fresh produce year-round. And it provides economic benefits to farmers who grow that food.