Dr Tim Naish, palaeoclimatologist and Director of the Antarctic Research Centre in New Zealand, analyses the Earth’s past climate by studying its rocks.
In this video Dr Naish explains the challenges scientists face when studying rocks in Antarctica, and the worrying findings that are emerging.
Antarctica has had an ice sheet on it for 35 million years, so getting to the rocks is a big challenge for scientists. Floating sea ice or ice shelves are used as platforms for drill rigs, which bore a hollow steel tube through the ice into the rocks of the sea bed.
Dr Naish and his team are able to read rock cores like a book. Each layer of rock records a period of time, taking us back tens of millions of years. The layers represent different types of sedimentary rock, which give us valuable information about ancient plant and animal life, and of past environmental conditions.
The composition of sedimentary rocks and the fossils found within them provide an insight into the Earth’s past, and can help us understand what might happen in the future.
Dr Naish’s records show that last time the Earth had the level of greenhouse gases it is predicted to have in the future, the West Antarctic ice sheet collapsed. Global sea level was 5m higher and the ice sheet didn’t return for almost a million years.
The sea level will rise significantly if the ice sheet cannot be sustained. Millions of people live within 1m of sea level, and current projections indicate the sea level will rise by this amount by the end of the century.