Ever-increasing CO2 levels could take us back to the tropical climate of Paleogene period

July 30, 2018, University of Bristol
Credit: CC0 Public Domain

A new study led by scientists at the University of Bristol has warned that unless we mitigate current levels of carbon dioxide emissions, Western Europe and New Zealand could revert to the hot tropical climate of the early Paleogene period—56-48 million years ago.

As seen from the ongoing , the knock-on effects of such extreme warmth include arid land and fires as well as impacts on health and infrastructure.

The early Paleogene is a period of great interest to change scientists as carbon dioxide levels (around 1,000 ppmv) are similar to those predicted for the end of this century.

Dr. David Naafs from the University of Bristol's School of Earth Sciences, led the research published today in the journal, Nature Geoscience. He said: "We know that the early Paleogene was characterised by a greenhouse climate with elevated carbon dioxide levels.

"Most of the existing estimates of temperatures from this period are from the ocean, not the land—what this study attempts to answer is exactly how warm it got on land during this period."

Scientists used molecular fossils of microorganisms in ancient peat (lignite) to provide estimates of land 50 million-years ago. This demonstrated that annual land temperatures in Western Europe as well as New Zealand were actually higher than previously thought—between 23 and 29 °C—this is currently 10 to 15 °C higher than current average temperatures in these areas.

These results suggest that temperatures similar to those of the current heat wave that is influencing western Europe and other regions would become the new norm by the end of this century if CO2 levels in the atmosphere continue to increase.

Professor Rich Pancost, Co-author and Director of the University of Bristol Cabot Institute, added: "Our work adds to the evidence for a very hot climate under potential end-of-century carbon dioxide levels. "Importantly, we also study how the Earth system responded to that warmth. For example, this and other hot time periods were associated with evidence for arid conditions and extreme rainfall events."

The research team will now turn their attentions to geographical areas in lower-latitudes to see how hot land temperatures were there.

Dr. Naafs said: "Did the tropics, for example, become ecological dead zones because temperatures in excess of 40 °C were too high for most form of life to survive?

"Some climate models suggest this, but we currently lack critical data.

"Our results hint at the possibility that the tropics, like the mid-latitudes, were hotter than present, but more work is needed to quantify temperatures from these regions."

Explore further: Greenhouse gases were the main driver of climate change in the deep past

More information: High temperatures in the terrestrial mid-latitudes during the early Palaeogene, Nature Geoscience (2018). DOI: 10.1038/s41561-018-0199-0 , https://www.nature.com/articles/s41561-018-0199-0

Related Stories

Hot tropical oceans during Pliocene greenhouse warming

June 29, 2014

The impact of the greenhouse gas CO2 on the Earth's temperature is well established by climate models and temperature records over the past 100 years, as well as coupled records of carbon dioxide concentration and temperature ...

How does El Nino warm the entire globe?

October 6, 2015

We regularly hear about how El Niño events raise the temperature across much of the planet, contributing to spikes in global average temperature such as the one witnessed in 1998, with severe bush fires, droughts and floods.

Regional adaptions can cool heat extremes by up to 2-3 C

January 30, 2018

New research published today in Nature Geoscience has found that climate engineering that modifies the properties of the land surface in highly populated areas and agricultural areas over North American, Europe and Asia ...

Recommended for you

After the Big One: Understanding aftershock risk

September 24, 2018

In early September 2018, a powerful earthquake on the island of Hokkaido in northern Japan triggered landslides, toppled buildings, cut power, halted industry, killed more than 40 people and injured hundreds. The national ...

National parks bear the brunt of climate change

September 24, 2018

Human-caused climate change has exposed U.S. national parks to conditions hotter and drier than the rest of the nation, says a new UC Berkeley and University of Wisconsin-Madison study that quantifies for the first time the ...

Ocean acidification may reduce sea scallop fisheries

September 21, 2018

Each year, fishermen harvest more than $500 million worth of Atlantic sea scallops from the waters off the east coast of the United States. A new model created by scientists at the Woods Hole Oceanographic Institution (WHOI), ...

5 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

gkam
3.1 / 5 (7) Jul 30, 2018
Thanks to Deniers and folk like the nasty Koch Brothers, we will find out too soon.
Tyrant
1 / 5 (8) Aug 01, 2018
More pseudo-science non-sense.

"carbon dioxide levels (around 1,000 ppmv) are similar to those predicted for the end of this century"

There is no credible prediction that CO2 levels will be that high at the end of the century.
gkam
3.4 / 5 (5) Aug 01, 2018
Tyrant needs to read this:
http://www.ipcc.c...ar5/wg1/
Then, he can come back and tell us what it tells him.
winthrom
2.3 / 5 (3) Aug 06, 2018
We should not pick on the Koch brother too much. They are in the oil business, and need to have shills in government who protect their business.
BoatRocker
5 / 5 (1) Aug 06, 2018
gkam - Nice thought, but do you really think Tyrant is going to look (let alone read) that?

Per your reference, ~1000ppm looks conservative at present rates.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.