# Environmental Science

## The long road to 0.075: a statistician’s perspective of the process for setting ozone standards

## Conference on the Mathematics of Sea Ice

Interesting mathematics arises in many areas of the study of sea ice and its role in climate. Partial differential equations, numerical analysis, dynamical systems and bifurcation theory, diffusion processes, percolation theory, homogenization and statistical physics represent a broad range of active fields in applied mathematics and theoretical physics which are relevant to important issues in climate science and the analysis of sea ice in particular.

## The Mathematics of Bats

2010 Fields Medal recipient, Cédric Villani, Director of the Institut Henri Poincaré in Paris, France, will give a Friday evening talk entitled The Mathematics of Bats.

## Oceans and Multiplicative Ergodic Theorems

In many physical processes, one is interested in mixing and obstructions to mixing: warm air currents mixing with cold air; pollutant dispersal etc. Analogous questions arise in pure mathematics in dynamical systems and Markov chains. In this talk, I will describe the relationship between obstructions to mixing and eigenvectors of transition operators; in particular I will focus on recent work on the non-stationary case: when the Markov chain or dynamical system is non-homogeneous, or when the physical process is driven by external factors.

I will illustrate my talk with analysis of and data from ocean mixing.

## Mathematics and the Planet Earth: a Long Life Together II

When Colombus left Spain in 1492, sailing West, he knew that the Earth was round and was expecting to land in Japan. Seventeen centuries earlier, around 200 BC, Eratosthenes had shown that its circumference was 40,000 km, just by a smart use of mathematics, without leaving his home town of Alexandria. Since then, we have learned much more about Earth: it is a planet, it has an inner structure, it carries life , and at every step mathematics have been a crucial tool of discovery and understanding. Nowadays, concerns about the human footprint and climate change force us to bring all this knowledge to bear on the global problems facing us. This is the last challenge for mathematics: can we control change?

This is a two-part lecture, investigating how our idea of the world has influenced the development of mathematics. In the first lecture on July 15, I will describe the situation up to the twentieth century, in the second one on July 17 I will follow up to the present time and the global challenges humanity and the planet are facing today.

## Mathematics and the Planet Earth: a Long Life Together I

This is a two-part lecture, investigating how our idea of the world has influenced the development of mathematics. In the first lecture (July 15), I will describe the situation up to the twentieth century, in the second one (July 17) I will follow up to the present time and the global challenges humanity and the planet are facing today.