How the Southern Ocean helped fuel Earth's warmest climate in 65 million years

nature & planetPhys.orgc. 50 million years ago · Southern Ocean

How the Southern Ocean helped fuel Earth's warmest climate in 65 million years

from Phys.org

About 50 million years ago, Earth experienced its warmest climate since the extinction of the dinosaurs. Global temperatures were more than 10°C higher than today, and atmospheric CO₂ concentrations reached around 1,600 parts per million. But what kept CO₂ levels so extraordinarily high for millions of years? An international research team led by the Max Planck Institute for Chemistry has identified an important piece of the puzzle: the Southern Ocean.

explained

The Early Eocene Climatic Optimum (EECO), also referred to as the Early Eocene Thermal Maximum (EETM), was a period of extremely warm greenhouse climatic conditions during the Eocene epoch. The EECO represented the hottest sustained interval of the Cenozoic era and one of the hottest periods in all of Earth's history.

From Wikipedia: Early Eocene Climatic Optimum (CC BY-SA 4.0) ↗

how it works

Deep water holds far more dissolved carbon than surface water. Where it rises to the surface, as it does in the Southern Ocean, some carbon escapes to the air. How strongly the ocean overturns and how much carbon the deep water holds therefore sets how much CO₂ ends up in the atmosphere.

so what

The Eocene is the closest natural analogue to a high-CO₂ future, so understanding what held its carbon dioxide up helps calibrate how the climate system responds to carbon. It shows the ocean can be a long-lived source or sink, not just a bystander.

fun fact

During the Eocene's warmth, palm trees and crocodile relatives lived in the Arctic.

Hampi was once one of the world's largest cities, until its Vijayanagara capital was destroyed in 1565

the gist

Hampi is a UNESCO World Heritage Site in Karnataka, India, with more than 1,600 surviving remains spread over 4,100 hectares. It was the capital of the Vijayanagara Empire from 1336 to 1565. Travellers from Persia and Portugal described it as a prosperous, wealthy and grand city with temples, markets and farms along the Tungabhadra River. By 1500 it was estimated to be the world's second-largest city after Beijing, and probably India's richest at the time. In 1565 a coalition of Muslim sultanates defeated the Vijayanagara Empire, its capital was conquered and destroyed, and the city was left in ruins. Hampi remains a religious centre, with the active Virupaksha Temple at its heart.

how it works

The city was built around a fortified core with temples, markets and water structures along the river, supplied by an extensive network of roads and waterworks. When the empire fell, the city was not rebuilt, so its stone monuments were left standing.

so what

Hampi shows how quickly a great city can vanish after a military defeat, and how a ruined capital can remain sacred. Its ruins give historians a view of medieval South Asia that few other sites can match.

fun fact

The name Hampi comes from Pampa, an old name for the Tungabhadra River.

From Wikipedia, the free encyclopedia · text CC BY-SA 4.0

Image: Wikimedia Commons

source: Wikipedia ↗

2 min

politicsshortCNA2:01

False allegations about Singapore’s hand in Indonesia’s markets and a made-up meeting

from CNA

CNA Verify has found close to 400 posts pushing falsehoods tying Singapore to Indonesia’s stock market rout and to a secret meeting that never took place. Together, they drew nearly 12 million views, and some were circulated by accounts that appeared to be working in concert, across multiple social media platforms.

Here’s how the disinformation campaign targeting Singapore was uncovered.

on YouTube: CNA ↗