Some of our ecosystems may pass some very drastic shifts with no possible return, says Christiane Rousseau, a mathematician in Montreal, and a member of the International Mathematical Union.
I am a mathematician and I work in dynamical systems, systems that depend on time. So for instance, in a model, you give yourself the rule: what happens from one day to the next. Once you have the rule, it allows you to answer what will happen in one month, in two months, etc. The idea of modelling is to have a very drastic simplification of reality. If you have too much detail, you don’t see anything. Look at the temperatures, meteorology. If you are looking to the weather every day in each part of the world you don’t see the picture. So you need simplification.
What does this approach bring to sustainable development?
When you have a very smooth movement, the feeling is that if things are moving slowly, you can come back slowly. Which is not the case if you are in a canoe on the river and then the fall is coming and suddenly you realize it’s going too fast and it’s time to stop, it’s too late. So in fact, this is one message that we have from dynamical systems. There are some tipping points, and if we pass a tipping point, no return is possible. So some of our ecosystems may pass some very drastic shift. We may pass the tipping point without feeling it.
How is this research linked to sustainable development?
One important tool of mathematics is optimization. So for instance, we know we will need to adapt to climate change, to mitigate. Optimization helps you to find where you can have the most efficient action with the highest impact.
What are your hopes in regard to the International Year?
It is very important that the governments understand how they can act the most efficiently, but also that the population is aware, and that they understand. And if they understand that the government are working for them, they are more likely to accept the decisions. And also the small communities may have an active role in making small initiatives within the community to move to sustainable development.