Rutgers Study Shows Previous Climate Change Was Caused by the Ocean and the Atmosphere

October 27, 2014

Earth

Past Climate Change Was Caused by the Ocean and Atmosphere

The ocean conveyor moves heat and water between the hemispheres, along the ocean bottom. It also moves carbon dioxide.

New research from Rutgers University provides a deeper understanding of the mechanisms of climate change, revealing that circulation of the ocean plays an important role in regulating the climate.

Most of the concerns about climate change have focused on the amount of greenhouse gases that have been released into the atmosphere.

But in a new study published in Science, a group of Rutgers researchers have found that circulation of the ocean plays an equally important role in regulating the earth’s climate.

In their study, the researchers say the major cooling of Earth and continental ice build-up in the Northern Hemisphere 2.7 million years ago coincided with a shift in the circulation of the ocean – which pulls in heat and carbon dioxide in the Atlantic and moves them through the deep ocean from north to south until it’s released in the Pacific.

The ocean conveyor system, Rutgers scientists believe, changed at the same time as a major expansion in the volume of the glaciers in the northern hemisphere as well as a substantial fall in sea levels. It was the Antarctic ice, they argue, that cut off heat exchange at the ocean’s surface and forced it into deep water. They believe this caused global climate change at that time, not carbon dioxide in the atmosphere.

“We argue that it was the establishment of the modern deep ocean circulation – the ocean conveyor – about 2.7 million years ago, and not a major change in carbon dioxide concentration in the atmosphere that triggered an expansion of the ice sheets in the northern hemisphere,” says Stella Woodard, lead author and a post-doctoral researcher in the Department of Marine and Coastal Sciences. Their findings, based on ocean sediment core samples between 2.5 million to 3.3 million years old, provide scientists with a deeper understanding of the mechanisms of climate change today.

The study shows that changes in heat distribution between the ocean basins is important for understanding future climate change. However, scientists can’t predict precisely what effect the carbon dioxide currently being pulled into the ocean from the atmosphere will have on climate. Still, they argue that since more carbon dioxide has been released in the past 200 years than any recent period in geological history, interactions between carbon dioxide, temperature changes and precipitation, and ocean circulation will result in profound changes.

Scientists believe that the different pattern of deep ocean circulation was responsible for the elevated temperatures 3 million years ago when the carbon dioxide level in the atmosphere was arguably what it is now and the temperature was 4 degree Fahrenheit higher. They say the formation of the ocean conveyor cooled the earth and created the climate we live in now.

“Our study suggests that changes in the storage of heat in the deep ocean could be as important to climate change as other hypotheses – tectonic activity or a drop in the carbon dioxide level – and likely led to one of the major climate transitions of the past 30 million years,” says Yair Rosenthal, co-author and professor of marine and coastal sciences at Rutgers

The paper’s co-authors are Woodard, Rosenthal, Kenneth Miller and James Wright, both professors of earth and planetary sciences in the School of Arts and Sciences at Rutgers; Beverly Chiu, a Rutgers undergraduate majoring in earth and planetary sciences; and Kira Lawrence, associate professor of geology at Lafayette College in Easton, Pennsylvania.

Publication: Stella C. Woodard, et al., “Antarctic role in Northern Hemisphere glaciation,” Science, 2014; DOI: 10.1126/science.1255586

Source: Rutgers University

Image: Rutgers University

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6 Responses to “Rutgers Study Shows Previous Climate Change Was Caused by the Ocean and the Atmosphere”

  1. James Jarvis Says:

    It is amazing how things go round. If they follow their existing lines of reasoning they will end up where we were in the early 1950s.
    Forget CO2, its contribution to climate and climate change is trivial.
    The evaporation of water to water vapour and its subsequent condensation back to liquid water as rain and snow is the driver that creates climate and small changes in the process, climate change. The thermodynamics are simple but impressive. The climate has been changing continuously for the last 3,500,000.00 years. I just fall to understand the current hysteria. It seems today that there are no polymaths, just specialists who know more about less and less until they end up knowing nothing.
    We are approaching the end of an interglacial, the planet is not going to get warmer, the atmosphere is going to cool. It will only be a few short generations before the ice returns.
    We won’t see it, our children won’t see it, their children won’t see it . We are just too transient to matter and anything we do, other than try blow all of ourselves up with hydrogen bombs doesn’t matter a damn. The Earth is quite capable of looking after itself.

    Reply

  2. TonyM Says:

    Perhaps someone should look at the rocks at southern tip of South America and the tip of the Antarctic peninsula, to see when the land bridge which originally joined them was broken.
    At a guess , it will coincide with the change in climate, as it would have changed the ocean circulation out of all recognition.
    Smoking guns are the huge circular head-on impact feature to the east of the two points and the apparently later, circumpolar track of the rolling contact of a planet-sized body which actually did the smashing.

    Reply

    • OldWhatsHisName Says:

      Did you notice that they didn’t seem to realize that the continental drift during that time could have been the driving force behind the current change?

      It would not take a terribly large amount of drift to cause major changes to currents particularly around Cape Horn.

      Reply

      • TonyM Says:

        @OldWhatsHisName:
        Cape Horn didn’t exist until the land bridge joining South America to Antarctica was smashed.
        Until that time a current going down the east side of SA would have had to go all the way around Antarctica to get to the west side of SA. After the bridge was broken it would have been able to just turn around Cape Horn; and there could be a circulating current around Antarctica.
        As I said: the ocean circulation would have changed out of all recognition.

        Reply

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