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
Image: Rutgers University
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.
Remember that scientists have to eat too and that means they MUST have something to “study” even if it is entirely made up of coleslaw and apple pits.
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.
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.
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.
No, CO2’s contribution to climate change is not trivial and water vapor can NEVER be the cause of the warming. Water vapor can only act as a feedback, because heat is what keeps it in the air. Warm air holds more moisture and water evaporates more with higher temperature. If the air cools, water vapor condenses out as precipitation.
Yes, water vapor does about 75% of the warming that keeps the planet from being a snowball in space.
But without the NON-CONDENSING greenhouse gases, of which CO2 is by far the most abundant, water vapor cannot be the cause of warming.
There are many things that can put CO2 in the atmosphere, including humans emitting about 40 billion tons a year. CO2 has a resident time in the atmosphere of Hundreds of Years. Water vapor’s resident time is 2-10 days.
Atmospheric CO2: Principal Control Knob Governing Earth’s Temperature
Andrew A. Lacis*, Gavin A. Schmidt, David Rind, Reto A. Ruedy
“Ample physical evidence shows that carbon dioxide (CO2) is the single most important climate-relevant greenhouse gas in Earth’s atmosphere. This is because CO2, like ozone, N2O, CH4, and chlorofluorocarbons, does not condense and precipitate from the atmosphere at current climate temperatures, whereas water vapor can and does. Non-condensing greenhouse gases, which account for 25% of the total terrestrial greenhouse effect, thus serve to provide the stable temperature structure that sustains the current levels of atmospheric water vapor and clouds via feedback processes that account for the remaining 75% of the greenhouse effect. Without the radiative forcing supplied by CO2 and the other non-condensing greenhouse gases, the terrestrial greenhouse would collapse, plunging the global climate into an icebound Earth state.”
“because changes in concentration of water vapor equalize in just over a week (8-10 days), and because most of those happen near the surface, water vapor is simply unable to effect a long term change in the radiative balance of the Earth, which happens in the upper troposphere, where it meets the stratosphere at a boundary called the tropopause.
Indeed, scientists have studied the radiative forcing capability of water vapor and found it to be -0.1 to 0.05 W m-2. Meaning that by itself, water vapor is incapable of driving a long term change in the surface temperature of the Earth, let alone the extra energy being sequestered into the oceans.
“Even large increases in anthropogenic water vapor emissions would have negligible warming effects on climate”
“The 100 year effective GWP for vapor emitted near the surface is -0.001 to +0.0005, making emitted water, at best, a thousand times less effective per kg at altering the heat budget of the Earth than emitted carbon dioxide”
My comment above has an error. Water vapor is responsible for 50% of the ambient greenhouse effect, not 75% as I said.
But that is not global warming.
The non condensing greenhouse gases are responsible for 20%,
CO2 does 80% of the warming by non-condensing greenhouse gases.
And here is what humans have done. CO2 has likely never increased this fast naturally.
Humans increased CO2 by over 80ppm in 58 years
Humans increased CO2 by 130ppm in 138 years
Nature caused CO2 increases over the last 450,000 years, from ice core data
80ppm increase — took 50,000 years
110ppm increase — 25,000 years
120ppm increase — 20,000 years
60ppm increase — 20,000 years
90ppm increase — 15,000 years
100ppm increase — 24,800 years
The numbers for 800,000 years would be similar, based on a graph going back that far.
CO2 can initiate global warming AND it can act as a feedback. Water vapor as a feedback Only.
Guess what was a major player in ending glacial periods (what people tend to confuse with ice ages)??
Martin et al. 2005;
Toggweiler et al. 2006;
Schmittner and Galbraith 2008;
Skinner et al. 2010;
Shakun et al 2012
According to the peer reviewed research by Shakun et al., 93% of the global warming happened AFTER the CO2 increase, when the last glacial period ended
Glacial periods (ice ages) come and go when Milankovitch cycles trigger those changes in climate. (changes in Earth’s orbit around the Sun, and the angle of the Earth’s axial tilt with respect to the orbital plane – the obliquity of the ecliptic)
But those Milankovitch cycles are not strong enough to melt ice sheets and warm the world to interglacial conditions on their own. Feedbacks that kick in after the initial warming are what do most of the warming.
And CO2 was a major player as a feedback.
The warming from CO2 causes other warming feedbacks to kick in, including emissions of more CO2 from oceans, methane, increased water vapor etc.
Now humans are Directly pumping CO2 into the atmosphere at the rate of about 40 Billion tons a year. So CO2 is acting as a climate forcing, not a feedback. That CO2 warms the atmosphere has been known since 1859. There is no question about that.
It’s been estimated that human emissions of CO2 and other greenhouse gases are nearly 3 times as strong as radiative climate forcing, as those Milankovitch cycles.
Oceans moving heat around is the distribution of heat Within the planet’s climate system
The extremely fast increase in CO2 from human activities has Greatly Increased the heat Within the system. This has been directly observed by satellites.
And over 90% of that excess heat has gone into the oceans.
Deniers have twisted facts into lies. A good example is the oft heard claim about human contribution to the flux of CO2 into the atmosphere being small compared with natural sources of CO2. This false argument IGNORES HALF THE CARBON CYCLE. All those natural sources also take carbon out of the atmosphere, and in fact are taking out more than they put it. Not so with human emissions of CO2. A small increase of a few ppm CO2 adds up over time.
annual sources of carbon:
land 120 Gt
ocean 90 Gt
human 7 Gt
annual sinks for carbon:
land 122 Gt
ocean 92 Gt
human 0 Gt
net change: 3 Gt – And it’s all human!
The Carbon Cycle
“Without human interference, the carbon in fossil fuels would leak slowly into the atmosphere through volcanic activity over millions of years in the slow carbon cycle. By burning coal, oil, and natural gas, we accelerate the process, releasing vast amounts of carbon (carbon that took millions of years to accumulate) into the atmosphere every year. By doing so, we move the carbon from the slow cycle to the fast cycle. In 2009, humans released about 8.4 billion tons of carbon into the atmosphere by burning fossil fuel.”