I’m sure you may have seen the image I produced of the world 34,000,000 years ago. Well, after a little bit of tweaking to make it more scientifically accurate (to the best of our knowledge) it has been featured in a recent article in Science and an article I wrote for the Climate Lab Book blog. For the updated image, with different vegetation and the early Antarctic ice sheet, see the bottom right picture below.
As well as producing this image for my own research, I became interested in producing other images of times in the Earth’s history when it might have looked recognisably different to today. Inspired by some of the work by other PhD researchers at the University of Bristol. Here’s what they show.
Late Cretaceous (left hand image): looking over the north pole with Asia on the right, North America in shadow on the left and Greenland and Europe at the bottom.
High atmospheric CO2 during the Late Cretaceous, approx. 70 million years ago, meant the planet was ice free, even at the poles. Fossilised crocodilian and turtle remains from this period have been found at high northern latitudes in Asia and North America.
Ecological niche model results suggest a more equable climate system during the Late Cretaceous where high latitude temperatures were greater than turtle critical thermal minima. This allowed freshwater and terrestrial groups to occupy more northerly regions than their modern-day relatives.
Acknowledgements: The base palaeogeography was provided by Getech PLC and the vegetation distribution was loosely based upon the model simulations of Claire Lopston. Additional thanks go to Amy Waterson for her contributions to the caption.
Messinian (top right/featured image): looking over the complex, braided Mediterranean-Atlantic gateway before it was the single Strait of Gibraltar.
The Messinian salinity crisis, approx. 5.5 million years ago, occurred when the Mediterranean region underwent significant palaeogeographic changes driven by the motion of the African and Eurasian plates. Tectonic uplift restricted the flow between the Atlantic and Mediterranean, causing the latter to desiccate and become hypersaline.
This catastrophic event sequestered around 6% of the Earth’s sea salt from the global ocean and precipitated evaporites (e.g. gypsum and halite) across the Mediterranean Sea, which at times became as much as ten-times saltier than today.
Acknowledgements: The base palaeogeography was taken from Markwick (2007), the detailed Mediterranean gateway dimensions taken from Simon & Meijer (2015) and Flecker et al. (2015) and the vegetation distribution was taken from the model simulations of Alice Marzocchi. Additional thanks go to Alice for her contributions to the caption.
These images were produced but not displayed at NSPPS. Here is a little more information that was to go with them.
Wish you were here…
Artistic representations of the world as it once was
At first glance, palaeoclimate might seem like an abstract research field – it doesn’t directly affect me today and it probably won’t directly affect me tomorrow. People are far more concerned with interest rates, migration and what Trump could possibly say next…
Studying palaeoclimate helps me remember that there are forces at work that are far bigger and longer lasting than us. The Earth is not stationary and it will always change; even the very continents we stand on have not always been the same. I hope these images help you think outside our human bubble about our changing planet.