- Around 50 million years ago, the Arctic region was a warm temperate forest rather than today's frozen landscape. This was due to much higher CO2 levels during a period known as the Eocene hothouse. - A tiny aquatic fern called Azolla that grew in the Arctic's freshwater lakes and rivers is theorized to have caused global cooling. Azolla absorbed large amounts of CO2 from the atmosphere, eventually storing it in peat deposits on the lake and sea floors. - Within 800,000 years of the "Azolla Event", CO2 levels dropped by over 75%, Antarctic ice sheets formed, and global temperatures declined, marking the transition to today's cooler "Icehouse Earth" climate

1. The Azolla Event The Creation of the Modern Earth’s Climate By Jeff Taylor Olympus High School Get You High School Diploma Online!

2. Today’s Rocks Explain The Past’s Climate

3. Did you know that the Arctic Circle was a warm swamp 50 million years ago? Then Now

4. Ellesmere Island Today One of the northernmost pieces of land on Earth Very cold, very dry, very dark in winter Winters average high -30° C (-22° F) Summers average high 6°C (43° F) This is summer where you are lucky if it gets above freezing

5. Ellesmere Island 50 million years ago

6. South Carolina Today

7. Fossils of Ellesmere Island On this cold arctic island are preserved stumps and fossils of an ancient temperate forest, which had a climate similar to South Carolina today! http://thecanadianencyclopedia.com/index.cfm?PgNm=TCE&Params=A1ARTA0010389

8. But, How Could That Be? Today 50 Million Years Ago

9. The Position is Similar Sometimes different climates can be explained by movement of continents due to plate tectonics. But, in this case, Ellesmere Island is pretty close to where it was 50 million years ago. North Pole Lomonosov ridge

10. So, What’s The Deal?

11. Hothouse Earth For over 200 million years, up to and past the extinction of the dinosaurs, the Earth was much warmer than it is today. How much warmer? About 8-10° F worldwide average temperature. That was enough to have forests in Antarctica and tropical jungles in Seattle. Carbon Dioxide levels were some 6 times higher than today.

12. The EoceneAbout 50 Million Years Ago Dinosaurs had been extinct for 15 million years Mammals were becoming the dominant animal on Earth It was tropical all the way north to the Pacific Northwest It was temperate all the way to the poles No ice caps at either poles and no glaciers

13. Evolution of the WhaleEocene Brought About Remarkable Mammalian Evolution

15. Antarctica was covered in forests and there were no glaciers

16. India has not yet hit Asia, so the Himalayas could not block moisture.

17. South America and North America were not connected, so ocean currents could go right between them and animals could not cross back and forth.

19. Ocean currents could transport heat better due to the configuration of the continents.

21. Ice caps formed over Antarctica

23. Meet Azolla This is a tiny little aquatic fern found in swamps and bogs today

25. Is intolerant to freezing conditions

27. It can absorb a great deal of carbon dioxide from the air

28. When it dies, it can form peat layers at the bottom of the lakes

30. Like The Black Sea Today Due to its enclosed nature, the Black Sea is the least salty body of seawater connected to an ocean in the world. The Black Sea is only ½ as salty as the ocean. It is only habitable in the top 10% because the bottom 90% lacks oxygen. The bottom is anoxic, because there is little mixing to bring surface oxygen to the bottom. The bottom is much saltier than the top, since saltwater sinks.

31. Azolla Event With Azolla doubling its mass every few days, it sucked up huge amounts of Carbon Dioxide from the atmosphere. As layer upon layer of this “superplant” died and sank to the bottom, thick deposits of organic material formed on the sea floor. This permanently stored the CO2 under the ocean. Lower levels of this greenhouse gas meant less solar energy captured and reduced temperatures. Within 800,000 years, the CO2 levels had dropped from 3500 ppm to 650 ppm and ice caps began to form on the poles. Just like that, the Azolla could not grow in this region anymore, but the “damage” was done. Coal Seam

32. Carbon DioxideAre we inching back up to a Hothouse Earth? When we burn fossil fuels like coal, oil, and natural gas, we are taking the CO2 that was removed from the air by plants millions of years ago and are returning to back to the atmosphere.

33. Relationship Between CO2 and Temperature Before 1800, we were essentially “carbon neutral”. That is because CO2 came from sources that absorbed it like plants and wood. But, with the Industrial Revolution, we really started pumping extra CO2 from burning coal and then oil to power industry and transportation

34. Azolla Deposits Means Money? Much of the current energy exploration in the Arctic is to gain access to these ancient Azolla deposits. Of course, that would mean releasing that ancient stored carbon back into the air when it is burned. The ironic thing is that global warming actually makes it easier to access these deposits, because the sea ice will melt faster.