As the race for the next International Olympic Committee president heats up, climate change and sustainability have emerged as defining issues.

Just days before the International Olympic Committee (IOC) elects a new president in Greece more than 400 athletes on Friday called on the future leader of the body to strengthen its action for the environment.

IOC presidential candidate Sebastian Coe says the impact of climate change on the global sports calendar will be a priority issue if he wins the election next week.