NBC News: Problems with climate models are 'bad news for the climate research community' 'could erode trust in climate science' 'downplay natural variability'

NBC News, typically the most alarmist network on global warming, published a surprisingly balanced article today on the new paper finding excuse #8 for the 'pause' in global warming: Pacific trade winds. 

Among the eye-opening quotes in the article are:

• The "head-scratcher of a discrepancy between the temperature trends churned out by climate models and those observed in the real world"
• "If you let the models do what they want to do without constraining them by observations, then they will not reproduce the hiatus,"
• "And they don't do that because ... they do not reproduce this cooling over the past 10 or 20 years in the tropical Pacific. Instead they show, on average, warming."
• "The picture is further muddled by the fact that "longer-term climate models have these winds weakening over the 21st century; that is to say 100 years from now they should be weaker. The fact that they have gotten stronger over the past 20 years, I think, is a surprise,"
•  "It suggests that there is something that is happening in the real system that is not quite captured in the models."
• "The shortcomings of the climate models highlighted in this new paper feed into larger criticism that the models play down the importance of natural variability in the global climate system. "
• it is bad news for the climate research community because it does point to a potential problem for the climate models."
• A problem with the models, in turn, could erode trust in climate science
• The inability of the models to capture the observed wind trends and thus the hiatus is "just one small process in the global system that seems to need improvement,"

Global Warming Pause? The Answer Is Blowin' Into the Ocean

BY JOHN ROACH NBC News 2/9/14 [with added notations, emphasis, links]

For the past 13 years, global surface air temperatures have hardly budged higher despite continual pumping of planet-warming gasses into the atmosphere from the engines of modern life. Does this prove global warming is a giant hoax? No, according to a new study, which says the missing heat is being blown into the western Pacific Ocean by extraordinarily powerful and accelerating trade winds.

"Their acceleration over the last couple of decades is way stronger than you've ever seen in a climate model, about twice as strong," Matthew England, a climate scientist at the University of New South Wales in Sydney, Australia, told NBC News. "This is an unprecedented level of strengthening and it is strong enough that it is actually pushing heat in the Pacific Ocean into the ocean's interior," he added.

[Actually, the authors admit in the paper that the "unprecedented level of strengthening" can only be said to be since the beginning of the satellite era in 1979, since observations prior to satellites are very sparse and "unconstrained."]

As the heat is drawn down into the ocean's interior, cooler water rises to the surface and cools air temperatures. When — it's not a matter of if, noted England — the winds slacken, the heat stored in the Pacific Ocean will return to the atmosphere, allowing the surface air temperatures to spike higher and "catch up to the original projections of global warming in under a decade."

The finding reported Sunday in the journal Nature Climate Change helps the climate science community explain a head-scratcher of a discrepancy between the temperature trends churned out by climate models and those observed in the real world, noted John Fyfe, an expert on the so-called warming hiatus at Environment Canada in Victoria, British Columbia. He was not involved in the new research.

"If you let the models do what they want to do without constraining them by observations, then they will not reproduce the hiatus," he told NBC News. "And they don't do that because ... they do not reproduce this cooling over the past 10 or 20 years in the tropical Pacific. Instead they show, on average, warming."

Building consensus

The new paper is the latest contribution to an ongoing effort to explain the warming hiatus. Other theories range from sunlight blocking particles in the atmosphere to lower activity on the sun. In recent months, several researchers have converged on the idea that the oceans are absorbing much of the missing heat at some depth.

"...if you let the ocean cool, it can have a global effect, and the effect is of a magnitude that is consistent with the current flattened surface temperature curve."

A paper published Aug. 28 in Nature suggested that unusually cool surface temperatures observed in the Pacific Ocean could explain the warming slowdown. The new paper performs a similar calculation, but instead of the cooler waters, England and his colleagues added the intensifying trade winds, which lead to ocean surface cooling.

"They both show that if you let the ocean cool, it can have a global effect, and the effect is of a magnitude that is consistent with the current flattened surface temperature curve," Shang-Ping Xie, a climate scientist at the Scripps Institution of Oceanography in La Jolla, Calif., and a co-author of the Nature paper, told NBC News.

The new study brings clarity to the "sequence of cause and effect," noted Fyfe, "beginning with the trade wind intensifcation, the drawdown of heat into the ocean, meaning cooling at the surface. That has been an advance and very useful in our physical understanding of things." [So, increased winds -> cooling of ocean surface -> more heat sinking to bottom of ocean?]

One of the next questions, noted England, is what causes the trade winds to strengthen.

The answer begins with a poorly understood, multidecade oscillation between warm and cool periods in the Pacific. This mode of variability, he said, appears to underpin whether decades are dominated by the El Niño or La Niña weather patterns. In the cycle's cool phase, as it is in now, trade winds increase.

"That [natural, sun-driven] mode in the Pacific can explain about half of the wind trend," England said. What explains the other half, at this point, remains a mystery. Some evidence suggests it could be linked to warming in the Indian Ocean, though the mechanism, he stressed, is unclear. "It is not at all resolved yet why these winds are twice as strong as we would expect just from the oscillation," he said.

The picture is further muddled by the fact that "longer-term climate models have these winds weakening over the 21st century; that is to say 100 years from now they should be weaker. The fact that they have gotten stronger over the past 20 years, I think, is a surprise," England said, adding, "It suggests that there is something that is happening in the real system that is not quite captured in the models."

Model failure

The shortcomings of the climate models highlighted in this new paper feed into larger criticism that the models play down the importance of natural variability in the global climate system. "You want to have enough noise in your system" in order to get a realistic result, noted Xie.

That this shortfall is highlighted in the new research, he added, "is quite a nice result, but in a sense it is bad news for the climate research community because it does point to a potential problem for the climate models."

"The overall big picture that the planet is warming and that that warming is due to human influence stills stands with or without the hiatus."

A problem with the models, in turn, could erode trust in climate science, noted England. But "that would be akin to writing off the medical profession for finding out something new about an illness that they didn't know about earlier," he said.

The inability of the models to capture the observed wind trends and thus the hiatus is "just one small process in the global system that seems to need improvement," he noted. The long-term global warming trend, he added, is independent from decade-to-decade variability in the Pacific Ocean.

Fyfe echoed the sentiment. Instead of undermining climate science, he said, "What you are seeing here in this discussion is the natural evolution of science and improving our understanding. The overall big picture that the planet is warming and that that warming is due to human influence stills stands with or without the hiatus."

JOHN ROACH

John Roach is a contributing writer for NBC News. He started this role in November of 2005. Roach is responsible for environmental coverage on the website. Roach has also contributed to National Geographic... Expand Bio

Related: Also published today from Science Daily:

Pacific trade winds stall global surface warming ... for now -- ScienceDaily

The strongest trade winds have driven more of the heat from global warming into the oceans; but when those winds slow, that heat will rapidly return to the atmosphere causing an abrupt rise in global average temperatures.

Heat stored in the western Pacific Ocean caused by an unprecedented strengthening of the equatorial trade winds appears to be largely responsible for the hiatus in surface warming observed over the past 13 years.

New research published today in the journal Nature Climate Change indicates that the dramatic acceleration in winds has invigorated the circulation of the Pacific Ocean, causing more heat to be taken out of the atmosphere and transferred into the subsurface ocean, while bringing cooler waters to the surface.

"Scientists have long suspected [false] that extra ocean heat uptake has slowed the rise of global average temperatures, but the mechanism behind the hiatus remained unclear" said Professor Matthew England, lead author of the study and a Chief Investigator at the ARC Centre of Excellence for Climate System Science.

"But the heat uptake is by no means permanent: when the trade wind strength returns to normal -- as it inevitably [false] will -- our research suggests heat will quickly accumulate in the atmosphere. So global temperatures look set to rise rapidly out of the hiatus, returning to the levels projected within as little as a decade."

The strengthening of the Pacific trade winds began during the 1990s and continues today. Previously, no climate models have incorporated a trade wind strengthening of the magnitude observed, and these models failed to capture the hiatus in warming. Once the trade winds were added by the researchers, the global average temperatures very closely resembled the observations during the hiatus.

"The winds lead to extra ocean heat uptake, which stalled warming of the atmosphere. Accounting for this wind intensification in model projections produces a hiatus in global warming that is in striking agreement with observations," Prof England said.

"Unfortunately, however, when the hiatus ends, global warming looks set to be rapid."

The impact of the trade winds on global average temperatures is caused by the winds forcing heat to accumulate below surface of the Western Pacific Ocean. [False, heat rises due to convection]

"This pumping of heat into the ocean is not very deep, however, and once the winds abate, heat is returned rapidly to the atmosphere" England explains. [false due to 1st & 2nd laws of thermodynamics]

"Climate scientists have long understood that global average temperatures don't rise in a continual upward trajectory, instead warming in a series of abrupt steps in between periods with more-or-less steady temperatures. Our work helps explain how this occurs," said Prof England.

"We should be very clear: the current hiatus offers no comfort -- we are just seeing another pause in warming before the next inevitable rise in global temperatures."

Story Source:

The above story is based on materials provided by University of New South Wales. Note: Materials may be edited for content and length.