Future Officers

Context:

• Article is about evidence of rainforest near South pole 90 million years ago, the climate at this time was exceptionally warm with a higher level of carbon dioxide in the atmosphere than previously thought.

What is Rain forest?

• Rainforests are forests characterized by high and continuous rainfall, with annual rainfall in the case of tropical rainforests between 2.5 and 4.5 metres (98 and 177 in)
• The undergrowth in some areas of a rainforest can be restricted by poor penetration of sunlight to ground level.
• If the leaf canopy is destroyed or thinned, the ground beneath is soon colonized by a dense, tangled growth of vines, shrubs and small trees, called a jungle. The term jungle is also sometimes applied to tropical rainforests generally.

Climate of Antarctica as for we know:

• The climate of Antarctica is the coldest on Earth.
• The continent is also extremely dry (it is technically a desert), averaging 166 mm (6.5 in) of precipitation per year. Snow rarely melts on most parts of the continent, and, after being compressed, becomes the glacier ice that makes up the ice sheet.
•  Weather fronts rarely penetrate far into the continent, because of the “katabatic winds”.
•  Most of Antarctica has an ice-cap climate (Koppen classification EF) with very cold, generally extremely dry weather.
• The highest temperature ever recorded on Antarctica was 20.75 °C (69.3 °F)[1] at Comandante Ferraz Antarctic Station , beating the previous record of 18.3 °C (64.9 °F) at Esperanza Base, on the northern tip of the Antarctic Peninsula.

What does the recent research says about Antarctica;

• The carbon dioxide levels in the atmosphere were higher than expected 115-80 million years ago, challenging current climate models of the period.
• They analysed preserved roots, pollen, and spores from this soil, and showed that the world at that time — the Cretaceous period —was a lot warmer than previously thought.
• The mid-Cretaceous was the heyday of the dinosaurs but was also the warmest period in the past 140 million years, with temperatures in the tropics as high as 35 degrees Celsius, and sea level 170 metres higher than today.

The scientists compared the current evidence of a temperate rainforest in the region to what is found in New Zealand today:

• The finding is even more significant considering that the South Pole experiences only a four-month polar night, meaning for a third of every year there is no life-giving sunlight at all.
• According to the researchers, the presence of the forest suggests average temperatures in this region were around 12 degrees Celsius, with little likelihood for the presence of an ice cap at the South Pole at the time.
• The study noted that the evidence for the Antarctic forest is based on a core of sediment drilled into the seabed near the Pine Island and Thwaites glaciers in West Antarctica.
• One section of the core, they said, caught their attention with its strange colour.
• On scanning this section with an X-ray CT scan, the scientists discovered a dense network of fossil roots, which was so well preserved that they could make out individual cell structures.
• The samples noted in the study also contained countless traces of pollen and spores from plants, including the first remnants of flowering plants ever found at these high Antarctic latitudes.
• To reconstruct this ecology, the team

Conclusion:

• The scientists concluded that about 90 million years ago the Antarctic continent may have been covered with dense vegetation, with no land-ice masses on the scale of an ice sheet in the South Pole region.
• Before this study, the general assumption was that the global carbon dioxide concentration in the Cretaceous was roughly 1000 ppm.