Starship Asterisk*

Chris Peterson wrote:

Beyond wrote:I read an article a while ago that said scientists that studied the artic warming, discovered that most of the ice melt occurs from below the ice. They weren't expecting that. Apparently some of the ocean currents are changing. Maybe it's one of those 10,000 or 100,000 year cycle thingies?

It is antarctic ice shelves that are observed to be melting from the bottom, not arctic ice. And while some long term cyclical phenomenon may be responsible, the most likely explanation involves a slight speed increase in the eastward wind loop that circles Antarctica, caused by atmospheric warming in the southern hemisphere. That is a component of the rapid anthropogenic warming the Earth is now experiencing.

Beyond wrote:Chris, i don't remember seeing any 'ant' in the artic article i read about. :no: For some reason, i remembered about what you said about the Antarctic, but this article didn't mention any of that. It was for the top of the world, not the bottom. I suppose i should have posted it, but geeze, i gotta leave something for others to post. :mrgreen: IF i happen to come across it again, I'll post it.

Ann wrote:What about the weather where you live, Chris? And what about the rest of you U.S. residents?

rstevenson wrote:Chris, it's hard for those of us in wetter climes to imagine such dryness.

Just checking some records. Two factoids jump out at me...
1. The largest amount of rainfall in Halifax over one day in June -- 65.8mm -- occurred June 10th 1972.
2. In comparing local daily record precipitation amounts for June, no rainfall records have been set since 1984 and no snowfall records since 1993, with most such records being set in the 1970s. Evidence that our local climate is getting warmer and drier? Or is it too short a time period to make such a claim?

geckzilla wrote:I'd take Chris's 28 C or Rob's 30 C right now. It's 35 C here with a dew point at around 19 C. The heat index earlier today was 38. I've been outside working in 35 degree weather in So Cal before and that was hot but there's no getting me outside during this. The air feels heavy there's not a lot of trees to hide under. I'm scrawny and do a lot better in the heat than I do the cold but this kind of heat can be deadly.

Beyond wrote:Man... one of these days I'm going to have to get ... Oh, i do have C on my thermometer. I just never seemed to notice it before, just like not paying attention to the kph on my speedometer.
It was up to 37'C. Thundershowers missed me, but brought the temperature down anyway. It's now 24'C. Funny... if i don't think in F, it just doesn't seem to have any meaning. I guess I'm just stuck in the F rut. Heck, never had any use for C until i boarded the Asterisk*. Actually, i still don't have a use for C. I have to go look at the thermometer to translate it into a meaningful F.

Unlike the loss of sea ice, the vulnerability of polar bears and the rising human population, the economic impacts of a warming Arctic are being ignored.

....Permanently frozen ground, called permafrost, beneath the Arctic's East Siberian Sea could belch out 50 billion tons of methane at any time, researchers said in an analysis published today (July 24) in the journal Nature. More than a trillion tons of methane is thought to be trapped in the Arctic Ocean's icy marine sediments in the form of what are called methane hydrates, some of it in shallow water.
As the Arctic sea ice cover shrinks and the Arctic Ocean warms, the frozen sediments may thaw and release the stored methane, said study co-author Peter Wadhams, an oceanographer at the University of Cambridge in the U.K. Plumes of methane gas have already been rising each summer in the East Siberian Sea, Wadhams said.

"That's an economic time bomb that's not been realized at this stage," said lead study author Gail Whiteman of Erasmus University in Rotterdam, Netherlands.

Because methane traps atmospheric heat 25 times more efficiently than carbon dioxide, a sudden Arctic methane release would have a catastrophic effect on the global climate, the study authors said.

Adding 50 billion tons of methane to the atmosphere would hasten this century's predicted 3.6-degree Fahrenheit (2 degrees Celsius) global temperature rise by 15 to 35 years, the researchers said. (Climate negotiators hope to limit planetary heating by that 2-degree C target, though the Intergovernmental Panel on Climate Change uses a range that goes up to 4 degrees C (7.2 degrees F).)....

Beyond wrote:
On a 'lighter' note, after about a week of reaching into the 90's F, it's now 52' F and raining lightly. 52' F in the latter part of July Well, i guess it's not unheard of around here, but it sure is uncommon That said, it's a welcome change from the humid 90's.

I might even have to use a little bit of heat tonight.

• You could always hydrate.

mjimih wrote:More dire news from Journal Nature
http://www.nature.com/nature/journal/v4 ... 9401a.html

Unlike the loss of sea ice, the vulnerability of polar bears and the rising human population, the economic impacts of a warming Arctic are being ignored.

July 24th
http://www.livescience.com/38406-arctic ... lions.html
Global Price Tag for Arctic Thawing: $60 Trillion


When brought to the surface, methane gas will escape from the hydrate and can be burnt off as seen in this picture. Credit: Department of Energy

....Permanently frozen ground, called permafrost, beneath the Arctic's East Siberian Sea could belch out 50 billion tons of methane at any time, researchers said in an analysis published today (July 24) in the journal Nature. More than a trillion tons of methane is thought to be trapped in the Arctic Ocean's icy marine sediments in the form of what are called methane hydrates, some of it in shallow water.
As the Arctic sea ice cover shrinks and the Arctic Ocean warms, the frozen sediments may thaw and release the stored methane, said study co-author Peter Wadhams, an oceanographer at the University of Cambridge in the U.K. Plumes of methane gas have already been rising each summer in the East Siberian Sea, Wadhams said.

"That's an economic time bomb that's not been realized at this stage," said lead study author Gail Whiteman of Erasmus University in Rotterdam, Netherlands.

Because methane traps atmospheric heat 25 times more efficiently than carbon dioxide, a sudden Arctic methane release would have a catastrophic effect on the global climate, the study authors said.

Adding 50 billion tons of methane to the atmosphere would hasten this century's predicted 3.6-degree Fahrenheit (2 degrees Celsius) global temperature rise by 15 to 35 years, the researchers said. (Climate negotiators hope to limit planetary heating by that 2-degree C target, though the Intergovernmental Panel on Climate Change uses a range that goes up to 4 degrees C (7.2 degrees F).)....

7 degrees F is a disaster. All weather everywhere will become "different", causing ecosystem-shift, animal stress, invasive species creep, etc etc. We need to act now.

Dr Gavin Schmidt from Twitter wrote:Dr. Schmidt replied on Twitter in multiple tweets with an essay of bullet points. This marks the first time Dr. Schmidt publishes on WUWT, as well as the first essay here ever composed on Twitter.



I’ve collated his responses below.

Also the PETM (55 My) and Eocene small events. But no evidence under near-current temps. Outside of quaternary range of arctic temps, many fewer constraints…. Pliocene CH4 may well have been higher (but no direct evidence), multiple sources though…

Some more context on Arctic methane release story to follow:

Methane is an important part of the anthropogenic radiative forcing over 20thC. Human caused increase from 0.7ppm to 1.8ppm

Methane emissions have a direct GHG effect, and they effect atmospheric chemistry and strat water vapour which have additional impacts

Direct forcing from anthropogenic methane about 0.5 W/m2, indirect effects add about 0.4 W/m2. For ref: CO2 forcing is about 1.8W/m2

Natural feedbacks involving methane likely to be important in future – via wetland response to T/rain chng, atmos chem &, yes, arctic src

Monitoring and analysis of atmos conc of CH4 is very important. However, despite dramatic Arctic warming and summer sea ice loss ….. > …. In recent decades, little change has been seen in atmos concentrations at high latitudes.

There are large stores of carbon in the Arctic, some stored as hydrates, some potentially convertible to CH4 by anaerobic resporation

There’s evidence in deep time records of large, rapid exogenous inputs of carbon into climate system; leading theory relates this to CH4

It is therefore not silly or alarmist to think about the possibilities, thresholds and impacts for these kinds of events

In more recent past, there have been a number if times when Arctic (not necessarily globe) has been significantly warmer than today.

Most recently, Early Holocene, which had significantly less summer sea ice than even 2012. Earlier, Eemian 125kyrs ago was sig warmer

At neither of these times is there any evidence for CH4 emissions or concentrations in excess of base pre-industrial conditions.

This means that we are not currently near a threshold for dramatic CH4 releases. (Though we may get there)

Much of the concern re dramatic changes in Arctic methane come from one off surveys and poorly calibrated remote sensing

But we should not take what-if sensitivity experiments as predictions.