Here's a Glimpse at a Future Hothouse Earth if Greenhouse Gasses Aren't Curbed

Earth has been between a hothouse and an icehouse.

Human emissions of greenhouse gasses are reversing the natural trend of global cooling at a rapid and unprecedented rate.

Our planet experienced major upheaval about 304 million years ago when it went from an icehouse to a hothouse.

The atmospheric carbon levels doubled in about 300,000 years. A new study shows that about 23 percent of the seafloor was deprived of oxygen.

The findings are based on a new analysis of trace elements in a slab of ancient black shale in South China. On top of global warming, rising sea levels, and melting glaciers, we also need to worry about ocean anoxia.

Anoxia is a lack of oxygen. It can happen with climate change because ice caps can melt and add fresh water to the ocean.

Life in the ocean is hard to survive under anoxic conditions. Dead zones are areas with low oxygen.

The new results are supported by previous research which found major losses to the sea during the KGB boundary.

The authors of the current study realized the importance of timing when modeling ancient climate changes.

If you raised CO 2 by the same amount in a greenhouse world, there isn't much effect, but icehouses seem to be more sensitive to change.

If human emissions had increased during a natural period of global warming, ocean anoxia would not be as big of a threat.

Greenhouse gasses in a hothouse world are already high, so emissions don't have as strong a melting effect on ice sheets and permafrost.

During a period of global cooling, there are more ice sheets and glaciers trapping fresh water and blocking the flow of oxygen into the ocean.

Researchers think volcanic eruptions stimulated the release of carbon that caused climate change.

The carbon added to the atmosphere would be greater if there were more wildfires.

These are just ideas. The exact cause of carbon emissions during the KGB was not known, but the results show a clear spike in greenhouse gas emissions and sea level rise.

Massive carbon release with abrupt warming has occurred repeatedly during greenhouse states, and these events have driven episodes of ocean deoxygenation and extinction, according to the authors.

The records from these paleo events, along with biogeochemical modeling, provide clear evidence that with continued warming, the modern oceans will experience substantial deoxygenation.

The study was published in a journal.