Extreme Heat and Suffocation

This recent view sees the Permian mass extinction as a series of extinctions. Each extinction set off another one in a chain reaction. The massive volcanic eruptions in Siberia may have been the first part of this Permian chain reaction. These eruptions may have increased the world's temperature by releasing huge amounts of heat and molten lava. The volcano also released thick clouds of carbon dioxide. Carbon dioxide acts like a blanket that traps warm air on the surface of the planet. As temperatures soared, life began to die off in great numbers.

Marine plankton are tiny plants that live in the ocean. Scientists believe that marine plankton produce most of the breathable oxygen on the planet. Fossil records show that over 99% of all marine plankton died during the Permian mass extinction. This might explain the big drop in oxygen levels at the time. However, there were even more reasons oxygen levels went down.

Methane is a gas that is usually frozen in the coldest places on Earth. Scientists think the frozen methane melted like an ice cube in the Sun. This released the methane gas into the air. Methane sucks oxygen out of the air and transforms itself into

PHEW! DID ROTTEN EGGS HELP KILL PERMIAN LIFE?

Bacteria living on the bottom of the ocean produce a stinky gas called hydrogen sulfide. It smells like rotten eggs. It is also very poisonous. Scientists think this toxic gas killed a lot of life both on land and in the oceans. Currently, scientists are searching for fossilized green sulfur bacteria as evidence to prove this part of the theory behind the great carbon dioxide. Now the world got even hotter as more carbon dioxide trapped more warm air. It probably became even harder to breathe, as the oxygen levels in the air went down even further. Scientists think a lot of life's creatures may have suffocated without enough oxygen in the air.

This chain reaction of extinction continued. The surface of the Earth became hotter and hotter. Scientists estimate the temperature may have increased over 40°F (23°C). They think this combination of extreme heat, suffocation, or a mixture of both wiped out over 96% of all life during the Great Dying period around 250 million years ago. First, most life in the world's oceans became extinct. Life on land followed soon after. The entire Permian mass extinction lasted several million years.

CHAPTER FIVE

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