Blog Archive

Thursday, April 27, 2017

Pope Francis: Why the only future worth building includes everyone

Stefan Rahmstorf's letter to the editor of the New York Times cancelling his subscription due to their hiring Bret Stephens

To the Executive Editor
The New York Times
27 April 2017, via email

Dear Editor, 

I am a climate researcher, professor for physics of the oceans and have worked for eight years as advisor to the German government on global change issues. I regret to have to tell you that hereby I cancel my subscription to the New York Times in the wake of you hiring columnist Bret Stephens. Let me explain my reasons.

When Stephens was hired I wrote to you in protest about his spreading of untruths about climate change, saying “I enjoy reading different opinions from my own, but this is not a matter of different opinions.” I did not cancel then but decided to wait and see. However, the subsequent public defense by the New York Times of the hiring of Stephens has convinced me that the problem at the Times goes much deeper than a single error of judgement. It concerns its attitude towards seeking the truth.

The Times argued that “millions agree with Stephens.” It made me wonder what’s next – when are you hiring a columnist claiming that the sun and the stars revolve around the Earth, because millions agree with that? My heroes are Copernicus, Galilei and Kepler, who sought the scientific truth based on observational evidence and defended it against the powerful authority of the church in Rome, at great personal cost. Had the New York Times existed then – would you have seen it as part of your mission to insult and denigrate these scientists, as Stephens has done with climate scientists?

The Times has denounced the critics of its decision as “left-leaning.” This is an insult to me and was the final straw to cancel my subscription. There is no left-leaning or right-leaning climate science, just as there is no republican or democrat theory of gravity. I have several good climate scientist friends who have been lifelong republicans. Their understanding of climate change does not differ from mine, because it is informed by the evidence.

Quite unlike Stephens’ views on climate change, which run counter to all evidence. He is simply repeating falsehoods spread by various “think tanks” funded by the fossil fuel industry.

In December 2015, Stephens called global warming “imperceptible” and the Paris climate summit a “meeting to combat a notional enemy in the same place where a real enemy just inflicted so much mortal damage.” My colleagues and I have analysed 150,000 temperature time series from around the world, finding that monthly heat records occur five times more often now as a result of global warming than in an unchanging climate (Coumou et al., published in Climatic Change 2013). One of those record-hot months was August 2003 in western Europe. 70,000 people died due to this heat wave. Was global warming “imperceptible” to these people and the ones they left behind? On 15 August 2003, the New York Times reported: “So many bodies were delivered in recent weeks to the Paris morgue that refrigerated tents had to be erected outside the city to accommodate them all.” Was that just a “notional” problem?

Stephens doubts that global warming will continue, claiming that in hundred years “temperatures will be about the same.” That is a shockingly ignorant statement, ignoring over a century of climate science. Our emissions increase the level of CO2 in the atmosphere, it is higher now than in at least 3 million years. CO2 is a greenhouse gas, as demonstrated first in the year 1859 by physicist John Tyndall. CO2 traps heat – more CO2 means a warmer climate. That is basic physics, borne out by the history of climate. Denying these well-established facts is about as smart as claiming the Earth is flat, and best left to cranks, ideologues and fossil fuel lobbyists.

Stephens has claimed that “in the 1970s we were supposed to believe in global cooling.” That’s an age-old climate denier myth. It would have cost Stephens just 60 seconds with Google to find out it is wrong. (Try and google “Did scientists predict an ice age in the 1970s.”) But Stephens is clearly not interested in evidence or seeking the truth about matters.

Last Friday, you sent me an email with the subject: “The truth is more important now than ever.” It made me cringe seeing this in my inbox. It said “thank you for supporting news without fear or favor.” The hypocrisy of that is unbearable, and I will support your newspaper no more. Instead, I will give the money to ClimateFeedback.org, a worldwide network of scientists sorting fact from fiction in climate change media coverage. It is much better invested there.

Best regards,

Prof. Stefan Rahmstorf 
Head of Earth System Analysis, PIK

Wednesday, April 26, 2017

Ancient methane 'burp' points to climate change 110 million years ago

Frozen methane hydrates suddenly thawed 110 million years ago during a warming phase

by Jimmy Thomson, CBC News,April 24, 2017
Over 130 mounds like this one were discovered dotting the landscape of Ellef Ringnes Island, 500 kilometres north of Resolute, Nunavut. They point to an ancient release of methane.
Over 130 mounds like this one were discovered dotting the landscape of Ellef Ringnes Island, 500 kilometres north of Resolute, Nunavut. They point to an ancient release of methane. (submitted by Steve Grasby)
New research suggests a large amount of methane was released in the Arctic Ocean during a period of warming 110 million years ago and the methane "burp" points to the possibility of a similar release in today's warming conditions. 
The discovery happened in the remote High Arctic, on Ellef Ringnes Island, about 500 kilometres north of Resolute, Nunavut. During the Cretaceous period, 55 million years before the dinosaurs disappeared, the island was deep underwater.
Spaghetti rock
Fossils like these Cretaceous tubeworms show part of the deep-ocean community that fed off the methane leaking from the mud. (submitted by Steve Grasby )
Suddenly, from under the mud, bubbles of methane began to emerge as frozen deposits began to thaw.
The bubbles left traces in the form of over 130 mounds that persist on the island today, complete with fossils of life that formed around the methane seeps.
"There must have been some brief, rapid release into the ocean," explained Steve Grasby, one of the researchers who visited the island between 2009 and 2011. 
"Because we don't see them in the older rocks and we don't see them in the younger rocks. So something must have happened in the Earth's history at that time to release a bunch of methane into the sea," he said.  

Evidence of ancient climate change 

The thawing of the so-called methane hydrates coincides with a period of warming following a volcanic eruption, which released a cloud of carbon dioxide into the atmosphere. 
"That was when Earth transitioned from a cold climate to a warm climate," Grasby said.
"So we see this sudden and short term release of methane is coincident with this period of global climate warming." 
Today there are still deposits of methane hydrates buried under the sea. There have been concerns that their thawing could cause runaway climate change, since methane is a powerful, though short-lived, greenhouse gas that could further warm the climate, melting ever more hydrates. 
recent review by the United States Geological Survey says "most" of the methane never reaches the atmosphere. 
Grasby says his research points to a period in the Earth's geologic history when warming was releasing the gas from its frozen state, but, like today, it's hard to say what happens next.

Climate change doubles size of Canadian lakes in N.W.T. bison sanctuary, reducing habitat

Study looked at satellite imagery of Mackenzie Bison Sanctuary between 1986 and 2011

The Canadian PressFebruary 23, 2017
Bison are a common sight along N.W.T. Highway 3 between Fort Providence and Behchoko, near the Mackenzie Bison Sanctuary.
Bison are a common sight along N.W.T. Highway 3 between Fort Providence and Behchoko, near the Mackenzie Bison Sanctuary. (Sara Minogue/CBC)
New research suggests that climate change has mysteriously caused lakes near Fort Providence, N.W.T., to nearly double in size, forcing a herd of at-risk bison to stray from their preferred habitat.
Lakes in the Mackenzie Bison Sanctuary off the northwest shore of Great Slave Lake are now bigger than any time in at least the last 200 years, said Josh Thienpont, a University of Ottawa scientist and a lead author on the paper, published Thursday in the journal Nature.
"The whole landscape does appear to be getting wetter," he said.
Thienpont and his colleagues grew intrigued with the 10,000-square-kilometre sanctuary after people from Fort Providence, N.W.T., pointed out things were changing.
"Some of the local community had noticed that it was more difficult to travel on the landscape because it was wetter," Thienpont said.
Thienpont and his colleagues examined satellite imagery of the area between 1986 and 2011. They found the proportion of the land covered by water had almost doubled, from 5.7 per cent of the total area to as high as 11 per cent.
Some lakes didn't change much. But some had grown dramatically, including one that is now more than eight times larger.

Increase over time

That was enough for the team to suspect climate change.
"The change seems to be an increase over time," said Thienpont. "It's not just up and down.
"It seems that many of the things that are going on in this region in terms of water levels, precipitation, temperature, would favour the kind of lake increases that we're recording."
That suspicion was confirmed when they looked at soil and sediment analyses. The lakes are now bigger than any time during at least the last two centuries, meaning the expansion couldn't be the result of long-term natural cycles.
Still, it's a complex landscape and exactly how climate change acts to flood the lakes isn't yet well understood.
"That's something we're working on, to try and isolate that mechanism. There's a lot of potential drivers and there's probably not a single driver."
But the impact is clear on the sanctuary's 2,000 to 3,000 bison — Canada's last herd of genetically pure, tuberculosis-free wood bison, considered a species at risk. As the lakes grow, they drown out the sedge meadowlands around their banks that are the animals' favourite food.

Bison straying outside sanctuary

Aerial surveys done by the Northwest Territories show the animals are increasingly straying outside the sanctuary. They are an increasing hazard on Highway 3, which forms its western border.
"The flooding of this area may be resulting in the movement of the bison out of that preferred habitat," Thienpont said. "There is the potential to find bison not too far from Yellowknife now, which was not the case before."
What's happening in the sanctuary is unusual. Many northern areas are responding the climate change by getting drier, with lakes draining away as permafrost melts beneath them.
The sanctuary is a reminder that climate change impacts vary, said Thienpont.
"It shows that the same stressor can have varying impacts in different landscapes. It shows the responses of ecosystems are complex and the consequences of climate warming can impact every component of an ecosystem — not just the terrestrial, but also the animals living in an area."

'It scares me': Permafrost thaw in Canadian Arctic sign of global trend

Buildings in Inuvik being demolished because of shaky foundations

by David Michael Lamb, CBC News,April 17, 2017

Jim McDonald, the mayor of Inuvik, stands in front of a warehouse that’s slated for demolition due to melting permafrost, which has shifted the building's foundation.
Jim McDonald, the mayor of Inuvik, stands in front of a warehouse that’s slated for demolition due to melting permafrost, which has shifted the building's foundation. (David Michael Lamb/CBC)
Canada is melting.
Like a popsicle taken out of the freezer and left on the counter, the permanently frozen ground in the northern reaches of this country is thawing at an ever faster rate.
Half of Canada is blanketed in some form of permafrost, including patches in the northern reaches of Ontario and the Prairie provinces.
But in many places, including around Inuvik, NWT, as much as 90 per cent of this "ground" is actually frozen water. (The rest is dirt, rocks and decomposed organic material that was once trees, shrubs, even animals.)
For years now, buildings in Inuvik have been gradually sinking into the ground as it softens. Others are so unstable, they are literally sliding off their foundations.
Unstable building
This building is now set to be torn down. Some of the stilts that support it have sunk and others have heaved up, leaving the building dangerously unstable. (David Michael Lamb/CBC)
"You can really see the effect of the permafrost," said Inuvik mayor Jim McDonald, standing in front of two warehouses built in the 1980s that are now unsafe to enter and are slated for demolition.
"The seasonal thaw is getting deeper now, and that wreaks havoc."
This is where a local problem becomes a global concern.
Scientists in the Northwest Territories, Alaska and Siberia are now realizing that as the ground under them melts, it will not only make life harder for the people living in the Arctic, but will in fact speed up climate change around the globe.

Temperature swings

The World Meteorological Organisation says the globe is now in uncharted territory, with temperatures in 2016 the hottest ever recorded.
Effects of climate change can be difficult to spot for most Canadians, but not in Inuvik.
Mackenzie Delta landscape
The landscape of the Mackenzie Delta is a maze of small lakes and rivers. This waterlogged environment has always been one of constant change, but the melting permafrost is now transforming it in ways no one has ever seen. (David Michael Lamb/CBC)
Jim McDonald has lived here his whole life — his father helped build the town when it was created from scratch in the 1950s.
He said that in the Mackenzie River Delta, the cold used to set in by October and stay that way into May. Temperatures would regularly dip to -40 and remain there for weeks at a time.
But McDonald said that in recent years, winters are much warmer and much shorter. It's also more unpredictable. Wild temperature swings are common.
The thaw is destroying buildings, forcing construction crews to change their methods. Buildings used to be hoisted on stilts sunk five or six metres into the ground. Nowadays, said McDonald, "they're finding that they have to go down in the 15- or 20-metre range to get a stable enough foundation."
In melting the permafrost, the changing climate is not only unsettling buildings but making transportation in the region more difficult.
For decades, the community of Tuktoyaktuk, on the shore of the Arctic Ocean, has relied on an ice road from Inuvik in winter. But because of warmer temperatures, the road's season is shorter and faces periodic closures as the ice shifts and becomes unstable.
This spring it will close for good, to be replaced by a permanent gravel road that will be known as the Inuvik-Tuktoyaktuk Highway.

'It scares me'

Above the Arctic Circle, the permafrost hasn't melted since at least the last Ice Age, more than 10,000 years ago. 
Kumari Karunaratne
Kumari Karunaratne, a permafrost expert who works with the NWT Geological Survey, says the effects of climate change in the north are 'scary.” (David Michael Lamb/CBC)
No one knows exactly what it will unleash when it melts. But no one thinks it will be good.
At the very least, it's changing the landscape. The Mackenzie Delta is a maze of small lakes and broad hillsides. People who live in Inuvik say they don't have to travel far from town in the summer to see craters that formed when the surface layer of land simply collapsed. 
They also see entire hillsides that have slid away, and have found entire lakes that have drained — as well as others that have been newly formed.
When permafrost thaws, all the organic material previously trapped in it releases methane into the atmosphere.
Permafrost slump
When permafrost melts, it can cause the land to collapse in dramatic fashion. In this scene from last summer, a drone captured the effects, which included the partial draining of a lake. (NWT Geological Survey)
"It scares me," said Kumari Karunaratne, a permafrost expert who works for the Northwest Territories Geological Survey. "This methane that's being released is being released over huge areas across the north. And it's continually seeping out."
Methane is a greenhouse gas that is 25 times more potent than carbon dioxide. So, as climate change speeds up the permafrost melt, the permafrost melt will exacerbate climate change.
By exactly how much, it's impossible to say. Karunaratne won't even try to guess, because measuring it is difficult and imprecise. The area where it's happening is vast and much of it remains uninhabited and unexplored.
But there are dramatic examples that show just how much methane is bubbling up from underground. Some lakes in the Arctic are so full of it, if you punch a hole in the ice you can light the escaping gas on fire.
YouTube has videos of researchers and others doing it in Alaska and Siberia. But the same thing is happening in the Northwest Territories.

Unleashing other problems

There are other problems, too.
Last summer in Siberia, the unusually intense summer heat melted the permafrost, exposing a reindeer carcass that had been embedded in it. 
That carcass was infected with anthrax, a deadly bacteria that had been locked in the ice. A 12-year-old boy died after being infected and at least eight others were sickened.
It opens up the possibility that other dangers could be unleashed.
Siberian researchers say a gravesite in one town contains bodies of people who died of smallpox in the 1890s. They were buried in the soil just above the permafrost, which is now melting. That's raising fears that smallpox, which was eradicated globally in 1977, could make a comeback.
RUSSIA-YAMAL/NENETS
A woman stands with reindeer in the Yamal-Nenets region of Siberia, Russia, where a 12-year-old boy died and 20 people were infected in 2016 after an anthrax outbreak. An unusually intense summer had melted the permafrost, exposing a reindeer carcass containing anthrax. (Denis Sinyakov/Reuters)
Sergey Netesov, chief of the virology laboratory at Novosibirsk State University, told the Siberian Times newspaper that there are thousands of graves in the region — some human, some cattle. 
The recent anthrax outbreak, he said, is "reason enough to finance research into the diagnostics and prevention of exceptionally dangerous infections."
Whether that happens or not, people in the Northwest Territories know they have no power to stop climate change. 
Global temperatures are already at record levels and the polar regions are feeling the effects more dramatically than anywhere else.
"There are really remarkable changes that are happening in a short amount of time," said Karunaratne.
And there's likely more to come.

Arctic climate warming higher and faster than expected

Open water in Arctic Ocean affecting weather patterns around world

by Margo McDiarmid, CBC News,April 24, 2017
A polar bear sits on ice in Lancaster Sound. A new report by 90 scientists says Arctic temperatures are rising faster than in the rest of the world, and animals that rely on ice for survival are facing increased stress and disruption.
A polar bear sits on ice in Lancaster Sound. A new report by 90 scientists says Arctic temperatures are rising faster than in the rest of the world, and animals that rely on ice for survival are facing increased stress and disruption. (Jimmy Thomson/CBC)

A new international report shows that Arctic temperatures are rising higher and faster than expected, and the effects are already being felt around the world.
"The Arctic's climate is shifting to a new state," warns the report.
"This transformation has profound implications for people, resources and ecosystems worldwide."
The Snow, Water, Ice and Permafrost in the Arctic assessment was written by more than 90 scientists from around the world who compiled the latest northern research on how climate change is affecting the Arctic ice and ecosystems.
It's part of the Arctic Monitoring and Assessment Program of the Arctic Council, which represents eight circumpolar countries.
Among the findings in this year's report:
  • The Arctic Ocean could be largely free of sea ice in the summer as early as 2030 or even before that.
  • Arctic temperatures are rising twice as fast as the temperatures in the rest of the world. In the fall of 2016 mean temperatures were 6 degrees higher than average.
  • Thawing permafrost that holds 50% of the world's carbon is already affecting northern infrastructure and could release significant amounts of methane into the atmosphere.
  • Polar bears, walruses and seals that rely on ice for survival are facing increased stress and disruption.
  • Changes in the Arctic may be affecting weather as far away as Southeast Asia.
"The Arctic is connected to the rest of the planet," said David Barber, who is a leading expert on Arctic ice at the University of Manitoba and one of the authors of the report.
"We are seeing the first and strongest signs of global warming in the Arctic. We knew this was coming, we knew 30 years ago that it was coming, and it is now here," said Barber in an interview with CBC News.

Open water during winter 

Barber said one of the most surprising results of the research is that there is now open water even during the winter in the Arctic Ocean. 
"We didn't think we would see that much open water in the winter," he said adding that it is occurring mostly on the Atlantic side.
"The Atlantic ocean water is penetrating further into the Arctic and it's upwelling towards the base of the sea ice, where it is melting the sea ice from underneath, this is one of the key findings."  
Last year saw a record low amount of winter sea ice.
Arctic Report Card
A fisherman drives a boat near the Arctic Circle in Ilulissat, Greenland, in 2016, during a visit to the area by then U.S. secretary of state John Kerry. The U.S. hosts the next Arctic Council meeting in Alaska next month, the first time the polar nations will meet to discuss climate change since Donald Trump was elected U.S. president. (Evan Vucci/Pool/Associated Press)
That open water may be affecting weather patterns. Increased heat from the open water is rising into the atmosphere, which in turn is causing the polar vortex, also known as the jet stream, to weaken in strength.
The jet stream is the line of powerful winds between the cold dry air of the North Pole and the warm moist air mass farther south. As it weakens, it disintegrates into a series of lobes dipping up and down, carrying cold air south and warm air north. 
Scientists believe that's the reason why we are seeing unseasonably frigid temperatures in places like Florida and unusually warm weather in the north.
"For example, last fall in November-December, the temperature at the North Pole was 32 degrees Fahrenheit higher than it should have been in November-December, because one of these lobes had extended all the way to the North Pole and was drawing up warm weather from California," said Barber. 
The report says the weakened jet stream is also causing extreme weather events like heavy rain in North America and heavy monsoons in Southeast  Asia. 
Amid the dire predictions, the report contains some hope. It says that while these changes in the Arctic will continue until 2050, they can be slowed down after that.
It predicts that if governments make substantial cuts to greenhouse gas emissions, like those contained in the Paris climate agreement, it can help to stabilize the warming trends in the Arctic and stop further loss of ice and snow by the end of the century.
This report is being released ahead of the Arctic Council meeting in Fairbanks, Alaska, on May 11, 2017. The U.S. is hosting the meeting, which will be the first time that Arctic nations including the U.S., Canada, Russia, Denmark, Finland, Iceland, Norway, and Sweden will gather to talk about climate change since Donald Trump was elected U.S. president. 
Trump has called climate change a Chinese hoax and his government is in the process of scrapping environmental measures designed to control carbon emissions linked to climate change. 

Snow, Water, Ice and Permafrost in the Arctic

DOCUMENT
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UPDATED: An Attack on One Monument is an Attack on All: Donald Trump’s Attack on National Parks, Public Lands and Oceans

The executive order is an attack on America’s national parks, public lands and oceans. 
  • National parks and public lands and waters help define who we are as a nation. Attempts to revoke or change the fabric of national monuments is an assault on our nation’s historical, cultural and natural heritage. 
  • The review will encompass about two dozen monuments created over the past two decades, and this action is a setup to try to undermine one of the nation’s most important conservation tools.
    The Antiquities Act was signed by President Teddy Roosevelt in 1906 to safeguard and preserve U.S. public lands and cultural and historical sites for all Americans to enjoy.  Sixteen presidents – eight Republicans and eight Democrats - have used this authority to protect places from the Grand Canyon to Acadia to Papahānaumokuākea in the Northwestern Hawaiian Islands.  The Act also helps tell a more complete story of our nation, protecting sites from Stonewall to Birmingham to Cesar Chavez.
  • The executive order is part of a larger effort to sell off America’s public lands and waters for fossil fuel development.
  •  There’s no doubt that a number of the national monuments targeted by the review hold resource potential that the oil & gas industry wants to access.  
  • Opening these special areas to development would threaten cultural and natural resources that could never be replaced.  Our national parks, public lands and waters protect a shared history and culture that are worth more than the minerals beneath them.
  • Groups like the American Petroleum Institute have made clear they see the Antiquities Act as a threat to oil & gas development. And, in the case of Bears Ears, the Western Energy Alliance has confirmed industry’s interest in drilling.   
  • A 120-day review (or 45 days, in the case of Bears Ears), makes a mockery of the decades of work that local communities have invested to protect these places for future generations.

  •  Behind each national monument — and the plans guiding their management — are well-documented facts about the cultural and natural resources under the monument’s protection. President Trump's administration or the Congress can’t shrink, eliminate or alter national monuments without undermining the very cultural and natural resources they protect.

  • While the details on how the review will be conducted are unclear, it’s hard to see this exercise as anything more than kabuki theater.  Any honest review of a national monument would be transparent, engage the public, and consider the decades of community engagement behind many of these monuments.  

  • Efforts to eliminate or shrink national monuments will hurt local economies.
  • National parks, public lands and waters are a critical part of the nation’s economy – especially for rural and Western communities that benefit from the tourism, outdoor recreation and quality of life associated with healthy public lands. 

  • Outdoor recreation alone generates $887 billion and 7.6 million jobs every year.  And in 2016, National Parks saw a record 331 million visits, contributing almost $35 billion to the U.S. economy.

  • Regions surrounding national monuments have seen continued growth or improvement in employment and personal income, and rural counties in the West with more federal lands had healthier economies, on average, than their peers with less protected lands.
This action is deeply unpopular – the public overwhelmingly opposes attacks on national parks, public lands and waters.

  • In the 2017 Conservation in the West poll conducted by Colorado College, 80% of western voters supported keeping protections for existing monuments in place while only 13% of western voters supported removing protections for existing monuments.
 Other recent polls have shown strong support for national parks and monuments.  A 2014 Hart Research poll conducted for the Center for American Progress showed that 90% of voters supported Presidential proposals to protect some public lands and waters as parks, wildlife refuges and wilderness.

No President has attempted to revoke a national monument – for good reason.
  • There are over 150 monuments that protect America’s cultural, historical, and natural heritage for future generations.  Notably, no president has attempted to revoke a predecessor’s monument designation, even where some initial public disagreement over the designation existed.

  • While several monuments established in the early part of the 20th century were later modified, none of the past boundary adjustments have been challenged – or upheld – in court.  

    Nicole Gentile, Deputy Director, Public Lands Project, Center for American Progress, c: 202-203-0758

Sunday, April 23, 2017

Spencer & Christy's model not working again: "A Comparative Analysis of Data Derived from Orbiting MSU/AMSU Instruments" by

Journal of Atmospheric and Oceanic Technology, Vol. 34, No. 1 (2017) 225-232; doihttp://dx.doi.org/10.1175/JTECH-D-16-0121.1

A Comparative Analysis of Data Derived from Orbiting MSU/AMSU Instruments

a  (Warrensville, NC, U.S.A.)

Received June 14, 2016; final form October 3, 2016; published online January 16, 2017.

Abstract
Spencer and Christy of the University of Alabama in Huntsville (UAH) recently introduced a new method to process MSU/AMSU satellite brightness temperature data with their version 6 (v6) data. A comparison of UAH v6 north polar lower stratospheric (TLS) data with that from Remote Sensing Systems (RSS) is presented, indicating a possible bias between 1986 and 1988. Comparing UAH and NOAA Center for Satellite Applications and Research (NOAA) TLS data produces a similar result. An additional analysis utilizing midtropospheric (TMT) data also found a similar bias. Comparing the NOAA TMT data for the May 2016 release against UAH and RSS TMT evidenced another excursion, dated at the middle of 2005, that was corrected in later releases. These comparisons reinforce the concerns expressed by other analysts regarding the merging procedure for UAH v6, repeating similar concerns regarding the earlier UAH v5 products. Any biases in the UAH, RSS, or STAR products would impact the trends calculated for these products and could explain the differences between these trends. Biases in the UAH series would also impact the UAH TLTv6 lower-troposphere product, which is a linear combination of the UAH TMT, tropopause temperature (TTP), and TLS series.



a Retired.

© 2017 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author e-mail: R. Eric Swanson,