How the climate can rapidly change at tipping points
During the last glacial period, within only a few decades the influence of atmospheric CO2 on the North Atlantic circulation resulted in temperature increases of up to 10 degrees Celsius in Greenland – as indicated by new climate calculations from researchers at the Alfred Wegener Institute and the University of Cardiff. Their study is the first to confirm that there have been situations in our planet’s history in which gradually rising CO2 concentrations have set off abrupt changes in ocean circulation and climate at “tipping points”. These sudden changes, referred to as Dansgaard-Oeschger events, have been observed in ice cores collected in Greenland. The results of the study have just been released in the journal Nature Geoscience.
Previous glacial periods were characterised by several abrupt climate changes in the high latitudes of the Northern Hemisphere. However, the cause of these past phenomena remains unclear. In an attempt to better grasp the role of CO2 in this context, scientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) recently conducted a series of experiments using a coupled atmosphere-ocean-sea ice model.
First author Xu Zhang explains: “With this study, we’ve managed to show for the first time how gradual increases of CO2 triggered rapid warming.” This temperature rise is the result of interactions between ocean currents and the atmosphere, which the scientists used the climate model to explore. According to their findings, the increased CO2 intensifies the trade winds over Central America, as the eastern Pacific is warmed more than the western Atlantic. This is turn produces increased moisture transport from the Atlantic, and with it, an increase in the salinity and density of the surface water. Finally, these changes lead to an abrupt amplification of the large-scale overturning circulation in the Atlantic. “Our simulations indicate that even small changes in the CO2 concentration suffice to change the circulation pattern, which can end in sudden temperature increases,” says Zhang.
Further, the study’s authors reveal that rising CO2 levels are the dominant cause of changed ocean currents during the transitions between glacial and interglacial periods. As climate researcher Gerrit Lohmann explains, “We can’t say for certain whether rising CO2 levels will produce similar effects in the future, because the framework conditions today differ from those in a glacial period. That being said, we’ve now confirmed that there have definitely been abrupt climate changes in the Earth’s past that were the result of continually rising CO2 concentrations.”
Learn more:How the climate can rapidly change at tipping points
The Latest on: Abrupt climate changes
[google_news title=”” keyword=”abrupt climate changes” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]- Cleaner air in China causes ‘sudden warming’ in North America, study findson May 14, 2024 at 11:02 am
Researchers say reduced aerosol emissions in China have led to rising sea temperatures and extreme weather in Northeast Pacific, from Alaska to California, affecting biodiversity and causing toxic ...
- Drought is the worst climate change threat for the Netherlandson May 14, 2024 at 1:57 am
Summer drought, as well as floods and a rise in sea levels are among the effects of climate change that will impact the Netherlands most, both socially and financially, the government’s environmental ...
- 'Large-Scale' Changes in Ocean Circulation May End Coral Reefson May 10, 2024 at 11:52 am
Scientists discovered that 2023 marked the worst year for coral bleaching in the Northern Hemisphere, with major reefs suffering.
- 3 BRILLIANT MINUTES: Could climate change contribute to earthquakeson May 9, 2024 at 8:06 pm
MIT researchers have made a connection between excessive rain and snow events to “earthquake swarms” in one part of Japan.
- The ‘tipping point’ that could drop Britain’s future temperatures by 10Con May 2, 2024 at 5:00 pm
"One thing that worries scientists is that there’s ‘paleo’ evidence - evidence of the climate from the past - in stuff like ice cores, that there have been very rapid and abrupt changes in the North ...
- Abrupt permafrost thaw releases more CO2 than expectedon May 2, 2024 at 9:30 am
The study provides compelling evidence that soil CO 2 loss becomes stronger upon abrupt permafrost thaw. This means that thermokarst areas are significantly more vulnerable to climate-induced ...
- Yellowstone Lake's weird resistance to climate change could be about to crackon May 1, 2024 at 9:00 am
Yellowstone's lake's ice cover has remained unaffected by increasing temperatures due to increased snowfall. But this could make it vulnerable to a sudden shift.
- How Abrupt U-Turns Are Defining U.S. Environmental Regulationson April 26, 2024 at 5:16 am
The polarization of politics means that rules are imposed, gutted and restored with each election. Experts say that’s bad for the economy.
- Yellowstone Lake's weird resistance to climate change could be about to crackon April 23, 2024 at 5:00 pm
But this could make it vulnerable to a sudden shift. In an unexpected discovery, scientists find climate change is yet to alter the ice cover on Yellowstone Lake. However, a tipping point may be ...
- Climate change is causing marine ‘coldwaves’ too, killing wildlifeon April 15, 2024 at 1:06 pm
This really shows the complexity of climate change, as tropical species would expand into higher-latitude areas as overall warming continues, which then places them at risk of exposure to sudden ...
via Google News and Bing News