This fall I had the honour of giving the convocation address. Here’s what I said:

“Mr. Vice-Chancellor, Chair of the Board of Governors, colleagues, graduates, and cheering section:

President Bacon has asked me to speak about sustainability and to give you some advice. He’s given me just 5 minutes. This won’t be easy for a professor, but here goes.

Sustainability means living in a way that respects the future.

To understand this, imagine a tree, a huge tree, a thousand-year-old tree that’s so big it takes 12 people joining hands to form a circle around the trunk. The tree is 20 storeys tall, and its crown would cover half a football field. It has millions of branches and twigs.

There actually used to be a lot of trees that big.

But this tree is imaginary. So now imagine that those millions of branches and twigs represent the huge diversity of life on earth, one twig for each of the millions and millions of different and strange creatures in the world – bees that dance, plants that talk to each other, fluffy white bats, birds that name their own babies, turtles that glow in the dark, fish that walk, shrimps that make a noise louder than a jet engine, frogs that fly, snakes that transform into parachutes, beetles that stand on their heads, …

I could go on, and on and on. So, we have this huge tree and its millions and millions of branches and twigs, one for each amazing kind of living creature.

Now, of course, one of those twigs represents human beings, though the human beings twig grew onto the tree only very recently. If the tree, which is a thousand years old, represents the history of life on earth, then the human beings twig appeared on the tree only 3 weeks ago.

And, just 30 minutes ago, in the tree’s thousand-year life, the human beings twig started to hack and chop at the rest of the tree in a destructive frenzy. We’ve already chopped off nearly one seventh of the entire tree of life. One seventh, that’s like if all of your Saturdays just disappeared. What took millions and millions of years to evolve is disappearing far faster than we can even document it.

This does not respect the future. It is not sustainable. Sustainability would mean that we stop doing all the things we do that destroy life on earth.

So now, here are two bits of sustainability advice for you.

First, shut down your cell phone, go outside, and find a bit of nature to love.

One of the most important things that my research group has discovered is that every little bit of nature counts. If a hundred people protect 100 bits of nature that all add up to 100 hectares of area, that’s just as good as protecting a one-hundred-hectare park. So don’t believe it if someone tells you that the bit of nature you love is too small to bother protecting it.

Your bit of nature could be a ravine or a pond in your neighbourhood. It could be a tree that you pass by on your way to work. Whatever it is, get to know it better, get to love it, and do whatever you can to protect it.

My second bit of advice is to be careful what you dream for.

I’ve heard quite a few convocation addresses, and a lot of them advise new graduates to follow their dreams.

The problem with that advice is that dream-following is actually what turned the human twig into an unsustainable, life-destroying mutant. So my advice is this: think carefully about your dreams. Learn about how your dreams would affect the rest of the living world around you, either directly or indirectly.

Would your dreams result in even more destruction of wetlands or forests or coral reefs or grasslands? Would your dreams increase carbon emissions to the atmosphere, making the climate crisis even worse? Would your dreams increase the use of toxic chemicals? If yes to any of these, please change your dreams. Find a dream that will help to heal the tree of life.

In other words, dream sustainably.”