Arctic Sea Ice 2016

The 26 year span pictured is but a single unicorn rainbow fart in the grand scheme of things.

In the 60's (around the time the Pope said it was "OK" to say the Mass in the vernacular rather than Latin) they thought we were heading into an ice age. And now, just a rainbow fart later, the threat is global warming and Latin is dead.

​

 

Source?

Here are mine:

Ice age: What were climate scientists predicting in the 1970s?

Mainstream Media
What was the scientific consensus in the 1970s regarding future climate? The most cited example of 1970s cooling predictions is a 1975 Newsweek article "The Cooling World" that suggested cooling "may portend a drastic decline for food production."

"Meteorologists disagree about the cause and extent of the cooling trend… But they are almost unanimous in the view that the trend will reduce agricultural productivity for the rest of the century."

A 1974 Time magazine article Another Ice Age? painted a similarly bleak picture:

"When meteorologists take an average of temperatures around the globe, they find that the atmosphere has been growing gradually cooler for the past three decades. The trend shows no indication of reversing. Climatological Cassandras are becoming increasingly apprehensive, for the weather aberrations they are studying may be the harbinger of another ice age."

Peer-Reviewed Literature
However, these are media articles, not scientific studies. A survey of peer reviewed scientific papers from 1965 to 1979 show that few papers predicted global cooling (7 in total). Significantly more papers (42 in total) predicted global warming (Peterson 2008). The large majority of climate research in the 1970s predicted the Earth would warm as a consequence of CO2. Rather than 1970s scientists predicting cooling, the opposite is the case.​

Northwest Passage Navigation: Northwest passage now ice free and easier to traverse

It’s about this time of year - especially after another low for Arctic ice, leading to the opening-up of sea routes through the Northwest (and Northeast) Channel - that some people try to claim that things aren’t that bad really because those routes have been open at various (vaguely specified) times in the past, and certain historical crossings are brought forward (e.g. “The ‘St. Roch’ went through back in the 1940s, so ice-levels must have been low then, too. Things can’t be that unusual now !”) as some sort of argument to try to lessen the seriousness of the sort of levels of Arctic ice that are now prevalent each year. But how valid are such arguments ? I will give details about the ‘St. Roch’ and its trips through the Northwest Passage (taken from the accounts from Henry Larsen, the boat’s captain – see pictures of him and the 'St. Roch' below), and compare them with more recent journeys and conditions, so it can be seen what sort of comparisons can be made.
. . .
The first recorded attempt was the East-West voyage of John Cabot in 1497, and various subsequent expeditions (by, most notably, Drake, Cook, Hudson, Parry, Ross, etc.) led to the gradual mapping of the Passage, until Robert McClure (in 1854, and the first to traverse it from West to East, albeit partly by sledge) charted the last major piece. After all this, including up to the early years of the 20th Century, it was finally concluded that commercial shipping was not possible and so interest waned. However, the Passage has become commercially important again because it is now more regularly navigable,
. . .
In fact, it wasn't until 1954 that a vessel managed to cross the Passage in the same direction in a single season but Larsen didn’t think that this Southerly route was likely to be commercially viable, and the following is his overall view of the journey:

“The three seasons of the short Arctic Summers from 1940-42 had been extremely bad for navigation, the worst consecutive three I had experienced as far as ice and weather conditions were concerned, and in my remaining years in the Arctic I never saw their like. Without hesitation I would say that most ships encountering the conditions we faced would have failed. I also believe that had we missed the single opportunity we had to get out of Pasley Bay, we most certainly would still be there, in small bits and pieces.” (3)


. . . the Northwest Passage these days, and the wide-ranging types of vessels that are able to pass through it, show without much doubt that no valid comparison can be made between the ‘St. Roch’s’ completions of the passage back in the 1940s and the numerous transits that can be made today – the former took a mind-set that is arguably little in evidence today (self-sacrifice, ideals, patriotism, etc.), while the latter show how virtually anyone can accomplish the passage these days.​

Bob Wilson

 

For @William Redoubt and @mojo : Making Sense of Climate Science Denial | edX

This is a free, self-paced training program that gives form and structure to climate studies. If you fancy yourself an ace global warming denier, here is the road map, the secret game plan of those you want to confront.

Bob Wilson

 

Gawdam republican nationalists.


SM-G900V using PriusChat mobile app

 

Antarctic sea ice extent. Now with century-scale flatness:

'Heroic' Antarctic explorers left sea-ice clues - BBC News
TC - Abstract - Estimating the extent of Antarctic summer sea ice during the Heroic Age of Antarctic Exploration

 

Mr. Redoubt, please don't attack mojo for his great interest in short-term Antarctic sea ice dynamics. I am sure it was meant with the best of intentions.

 

To paraphrase Neil Degrasse Tyson from the reboot of Cosmos; Watch the path of the dog's owner, not the wanderings of the dog.

Weather is impacted by all kinds of factors making it highly variable in the short term.

Climate is the result of factoring out all of the short term variability to see the long term trends.

Climate is changing, regardless of the cause. However, the direction of the change is the opposite that would be expected given the natural factors that drive climate change.

My recommendation: Don't buy any land under 25 feet in elevation if you plan to stay there long.

Bill the Engineer

 

aren't you moving to the shore?

 

First hand, eyewitness account of elementary school, junior high and high school science classes. Graduated in 1970. I have a very good memory.

 

Not for us to question Mr. Redoubt's memories. May they never fade.

So that they do not get called into question, better to not click on any of the following:

http://journals.ametsoc.org/doi/abs/10.1175/2008BAMS2370.1
Newsweek Rewind: Debunking Global Cooling
Climate Change: Prediction Perils

Not even one. Memories are precious things...

 

The beauty of science is that it is constantly trying to prove itself wrong. Remember back in the 1970's when the science magazines were all afraid of the coming Ice Age? Well, the next Ice Age just got cancelled due to the increased CO2 levels.

Bill the Engineer

 

so. in 50 years, who knows where we'll be headed.

 

Close enough. I graduated high school in 1968. <GRINS>

Still, Dr. James Hansen in the 1970s was calculating the temperature of the earth based upon the long-term, orbital changes only to discover our planet is hotter than it should be. After a little more analysis, he found the temperature data began to make sense when he incorporated CO{2} in the math model.

Dr. Hansen wasn't the first to propose this mechanism. Nobel Prize winner, Svante Arrhenius: Svante Arrhenius - Wikipedia

Arrhenius developed a theory to explain the ice ages, and in 1896 he was the first scientist to attempt to calculate how changes in the levels of carbon dioxide in the atmosphere could alter the surface temperature through the greenhouse effect.[18][19] He was influenced by the work of others, including Joseph Fourier, John Tyndall or Claude Pouillet. Arrhenius used the infrared observations of the moon by Frank Washington Veryand Samuel Pierpont Langley at the Allegheny Observatory in Pittsburgh to calculate the absorption of infrared radiation by atmospheric CO2 and water vapour. Using 'Stefan's law' (better known as the Stefan-Boltzmann law), he formulated his greenhouse law. In its original form, Arrhenius' greenhouse law reads as follows:

if the quantity of carbonic acid [CO2] increases in geometric progression, the augmentation of the temperature will increase nearly in arithmetic progression.
The following equivalent formulation of Arrhenius' greenhouse law is still used today:[20]

ΔF=αln⁡(C/C0)
Here C is carbon dioxide (CO2) concentration measured in parts per million by volume (ppmv); C0 denotes a baseline or unperturbed concentration of CO2, and ΔF is the radiative forcing, measured in watts per square meter. The constant alpha (α) has been assigned a value between five and seven.[20]​

Understandings and reports from 1970 have improve over time. It is why we continue to study and learn:

When I was a child, I spake as a child, I understood as a child, I thought as a child: but when I became a man, I put away childish things. 1 Corinthians 13:11​

Good luck in your studies,
Bob Wilson

 

Attacking mojo is never my goal. I am not a weather scientist (I work with $$$), and I have been looking for a reason to use my extensive knowledge of unicorn rainbow farts in a helpful way. Did you know they smell like freshly baked bread?

I actually think climate is changing. But it is just part of our short life, which like the bloom of a flower, quickly fades.

 

There Has Been No Significant Net Change In Arctic Sea Ice Extent In The Last 80+ Years

 

What is your source for your data? The dates along the bottom make no sense.

Oh, I see now where you got it. Graphs can be deceiving.

Bill the Engineer

 

Arctic Sea Ice News and Analysis | Sea ice data updated daily with one-day lag

I prefer my data in an easier to analyze format.

Bill the Engineer

 

This is very important. Fortunately we do not need to rely on derivative sources, but go to the original publication:

Rong Zhang (2015). Mechanisms for low-frequency variability of summer Arctic sea ice extent. PNAS 112(15), 4570–4575, doi: 10.1073/pnas.1422296112

Several marine circulation patterns were treated as proxies for sea-ice extent. Makes sense, as heat certainly arrives in the Arctic this way. From relationships measured for recent ice variations, a multi-term regression model was developed. Then hindcasted with one of the current climate models. Results were as shown above.

It’s a surprising day! Mojo has signed on to climate modeling, without regard to my frequently expressed doubts.

But as always with proxy-views into the past we are looking for concordance. A completely different set of proxies was used by:

Leonid Polyak, et al. (2010). History of sea ice in the Arctic. Quaternary Science Reviews 29: 1757–1778, doi:10.1016/j.quascirev.2010.02.010

Their graph differs, in particular concerning the unusualness of current ice extent. With different sets of proxies telling different stories, we could throw up our hands, choose one set as preferable, or search for additional proxies. That last choice seems good, but until then we can examine those two proxy lists and see if one seems more satisfying.