Greenland Ice-Loss Predictions Are Clouded By Clouds
Predicting where, how and how quickly Greenland’s ice will melt is difficult. Projections by the best models are cloudy, and new research suggests clouds are doing the clouding.
Currently, models of Greenland’s melting ice sheet put the greatest emphasis on the impacts of “greenhouse gas” emissions.
But new research, published this week in the journal Nature Climate Change, suggests the microphysics of clouds are equally important.
Under high emission scenarios, the uncertainties of Greenland ice sheet models are caused almost entirely by the uncertainties of cloud dynamics.
Cloud cover dictates the ice sheet’s longwave radiation exposure. When clouds over Greenland are thicker, they operate like an insulating blanket, encouraging longwave radiation and surface-level melting.
Thinner clouds are associated with reduced melt rates, researchers determined.
The uncertainty caused by clouds translates to a difference of nearly five inches of global sea level rise by the end of the century.
The accelerated melting of Greenland’s ice sheet could threaten many coastal communities across the globe. To better project this threat, authors of the new paper suggest scientists work to figure out how climate change will impact cloud dynamics in the Arctic.
“Observations of cloud properties in the Arctic are expensive and can be challenging,” lead author Stefan Hofer, a Ph.D. student at the University of Bristol, said in a news release.
“There are only a handful of long-term observations of cloud properties in the Arctic which makes it very challenging to constrain cloud properties in our climate models.
“The logical next step would be to increase the amount of long-term observations of cloud properties in the Arctic, which then can be used to improve our climate models and predictions of future sea level rise,” Hofer said.
Read more at UPI
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Herb Rose
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Hi Brooks,
“When the clouds over Greenland are thicker, they act as an insulating blanket … ”
The insulation has a temperature of -50 C. Hard to imagine that it is keeping anything warmer. The droplets of water in the clouds are not insulating, keeping the ice from melting, they are doing what liquid water does, transmitting the heat from the hotter gases high in the atmosphere to the ground. The thicker the clouds, the more heat is transferred to the surface.To determine the real kinetic energy (heat) of gas molecules in the atmosphere you must use the universal gas law, not a thermometer.
Herb
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Chett
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Hotter gases higher in the atmosphere? WTF!
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Herb Rose
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Hi Chet,
Have you looked at a graph of the measured temperature versus altitude? Why does the measured temperature increase between 15,000 feet and 50,000 feet? Are you familiar with the thermosphere?
Herb
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Charles Higley
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The temperature differential between the surface and space is absolute as space had no temperature, which is why we get incredibly low temperatures in Iowa on a clear star-studded night—there is no back radiation. Thus, when there are clouds, there is clearly going to be a downward emission of very low temperature IR from the clouds. It will clearly not warm the surface, being from -17 deg C air, but it will slow the ongoing melting. Is this warming the planet? No.
The planet is not driven by only what is occurring over Greenland—Greenland has a huge ice volume that would take thousands of years to melt even with >6 deg F warming, which is way beyond the alarmist predictions. As the same clouds in other regions will effectively increase the albedo of the planet, cooling will be going on as well. Clouds in the Arctic might slow melting, but clouds in the lower latitudes cause less solar input and cooling. It’s not a simply problem and the largest problem I see is that few people try to see the whole picture.
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Herb Rose
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Hi Charles,
While space has no temperature it does contain energy emitted by the sun. That energy only becomes evident when it reacts with matter. It is that energy coming from the sun that warms the Earth and it decreases with distance from the sun. The reason the temperature is low in the upper atmosphere is because there are few molecules (mass) to convey that energy, as kinetic energy, to other objects (like a thermometer) by convection (collisions). To get an accurate indication of the energy the upper atmosphere you cannot use temperature. The universal gas law says that as you add energy (heat) to an unconfined gas that gas will increase in volume. This means in hotter gases there will be fewer molecules (mass) transferring that heat to a thermometer so the only way to get an accurate reading of the energy in the atmosphere is to use the gas law to find the kinetic energy of the gas molecules at different altitudes.. If you use the search function of PSI to find my article “THE TEMPERATURE OF THE ATMOSPHERE” you will see that the kinetic energy of the gases in the atmosphere slowly increases in the troposphere, where water moderates the temperature, then increases rapidly above that when the boiling point of water is exceeded.
Herb.
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Makena
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And here I was thinking this website promoted climate realism, not this climate hysteria alarmism bullcrap!
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tom0mason
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It would be a GREAT time if we could the climate back to when Greenland truly was a green and productive land. So far we’ve just crawl out of the LIA to some moderate warmth.
Till then all we have are the doom-monkeys trying to invoke fear into everyone.
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richard
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Don’t worry , it’s summer time in Greenland and -12C at Base Camp.
http://www.summitcamp.org/status/webcam/
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