Birds are, especially canaries, are super sensitive to hydrogen sulfide and sour gas.

Human beings are often at their best when responding to immediate crises - car accidents, house fires, hurricanes. We are less effective in the face of enormous but slow-moving crises such as the loss of biodiversity or climate change.

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.

Think about a seed. Once it lands, it's stuck. It can't move to find better soil, moisture or sunlight. It's able to create every part of itself to grow and reproduce with the help of air, water and sun.

Our beliefs, our values shape the way we look out at the world and the way we treat it. If we believe that we were here, placed here by God, that this - all of this creation is for us, it's for us to go and occupy, dominate and exploit, then we will proceed to do that.

Salmon farming-the placement of large metal or mesh net cages in the ocean to grow fish-was pioneered in Norway in the 1960s. Since then, the industry has expanded to Scotland, Ireland, Canada, the US, and Chile, but is dominated by the same multinational corporations. Wherever it is practiced, net-cage salmon farming is controversial and raises serious environmental concerns.

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.