Pacific grey whales have shrunk by 13% in two decades, according to a new study that sheds light on the impact of climate change on marine mammals, and scientists fear this could have a significant impact on whale health. Also, an extensive aerial survey in South Sudan has revealed an enormous migration of 6 million antelope – the largest migration of land mammals anywhere on Earth.

We get the details from Dr Ruth Freeman Director of Science for Society at Science Foundation Ireland in this week's Green Scene.

All with thanks to AIB Ireland.