I searched Google for some data on global air temperatures, and came up with some interesting facts.
The information is from a Journal of Geophysical Research, VOL. 108, NO. D14, 4407, doi: 10.1029/2002JD002670, 2003

If you can get to the beginning of the report, scroll down to the fourth page, you will see two graphs indicating north and south hemisphere ice concentration.
What is very interesting is that there is a very sharp disruption/decrease in the concentration before the year 1950.
It is also interesting that several nuclear bombs were detonated in the atmosphere before the year 1950, and the total amount of radioactive material that such activity dispersed into the atmosphere must have been less than what we now get from leaking nuclear power plants.

Nuclear tests:

http://www.onlinenevada.org/1942_1950:_nuclear_testing_before_nevada

Journal of Geophysical Research:

https://docs.google.com/viewer?a=v&q=cache:B8azutPE96cJ:citeseerx.ist.psu.edu/viewdoc/download?doi%3D10.1.1.172.4502%26rep%3Drep1%26type%3Dpdf+global+air+temperature&hl=en&gl=ca&pid=bl&srcid=ADGEESjywMvI72oyGT-L10FYHpKV7Vg-J8IJjFLtGfHzhnzr1QVzKxxy6gJyEhA5lxh8GS8OlIvEu7Doy5YM3jZCO7dkhE1I1XnBoO_aYhMXO11GdgtmPq6JkfficnbLMaqspd_mwM1F&sig=AHIEtbQh8eJeYj4GHi1eJctYnH6rdHwdOA

Can I say I told you so.

And everything had thousands upon thousands of years to adapt. And every response was a local one.

Precursors of Homo Sapiens Sapiens went extinct. Others blossomed. None of them had armies, nuclear weapons, an ability to go clear ’round the world to rob others of their resources.

Now, this is happening so fast, that no one has time to adjust. And Homo Sapiens Sapiens regards itself as sacrosanct. Not only does Man not want to go extinct, Man’s various tribes regard themselves as more important that all the rest put together. The response will be global, as there are struggles over fresh water, food, and more struggles over energy.

It’s happening so rapidly that measured, gradual reactions aren’t possible. There is no simple evolution which allows people to migrate to avoid the effects. And nature doesn’t really care if Homo Sapiens Sapiens lives or dies.

And many Homo Sapiens Sapiens don’t care if Man lives or dies, either, as long as they can live their chosen lifestyle while they are around.

So the fundamentalists are right, in that this has happened before. They ignore what happened when it did, and they ignore the speed at which it is happening now. God gave man dominion over the Earth and Man screwed it up in only a few thousand years. So much for the survival value of big brains. With them come big egos, which self-destruct.

Exactly what kind of data processing is involved in delivering a measurement of global temperature across a century within a degree?

BTW, the very same NSIDC website where you lifted that graph from also says the following:

Warming at the South Pole?

Polar scientists say no on both counts. Ted Scambos, lead scientist at NSIDC, said, “These systems are not directly connected, and they certainly don’t offset each other. The climate and ocean processes that control summer Arctic ice extent are completely different from the ones that drive the Antarctic.” Data records indicate warming at both poles, but Antarctica’s geography is forcing warming to show in different ways than it does in the Arctic. “Antarctica’s trend is not nearly as large or as clear as the Arctic’s,” Scambos said.

http://nsidc.org/icelights/2012/11/14/arctic-melt-versus-antarctic-freeze-is-antarctica-warming-or-not/

As for your inaninties about publish-or-perish
conspiracies, Darwinianly deluded climatologists, UN Socialist cabals, and the untold billions to be made in unnecessary global warming mitigation are just anomalism on your part. Same-old, same-ole SDAI Soros soliloquies.

The real money is to be made in unrestricted sale of fossil fuels, untaxed, and subsidized by governments. That’s the industry where the money is actually being made now. That’s the industry where the propaganda money is being spent to continue those practices(“defensive response” my ass), and its the industry that has a history of doing whatever it takes to get its way. Remember, I used to work for both the energy and oil industries. Means, motive, opportunity…

TB, you just don’t want to admit you’re wrong, and you don’t want to admit why. And I’m tired of going over it. Come back and talk when you can come up with a cogent physical explanation of why summer sea ice at the N pole has dropped about 40% over the last 30 years, one that doesn’t involve black helicopters, bigfoot and Masonic Illuminati.

Unfortunately, most of the people and organizations pushing AGW are not very reasonable. They’re not calling for more study. They’re not wondering if maybe they don’t know all the facts.

Their ONLY response has been to call for vast amounts of power and wealth accrued to centralized government authorities (state, national, and international) and to attack every industry that involves combustion. When you say “do something,” this is the only “something” I have ever heard out there.

The defensive response of the industries shouldn’t be all that surprising.

Your personal belief is that self-interest, greed, and power-lust are only operating on one side of this discussion. As long as you stick to that, you’re not going to come up with a realistic analysis of either the problem or the solutions.

The global warming industry is worth many billions of dollars around the world, both in taxes and fees to governments, and industries feeding off of it. The U.S. “Green Energy” industry alone hauls in billions, a lot of it from taxpayers. These are businesses, too.

Scientists who toe the line get published and access to government funding. Others don’t. This is not corruption. The scientists aren’t inventing data. It’s natural selection. Scientists who point out different data or do different analyses aren’t heard. Most statistics I’ve seen about “80 percent of scientists” supporting AGW have the description in the fine print, “published scientists.” You can see how that might work. “Peer review” is basically just another way of one sheep and three wolves deciding what’s for supper.

The global weather machine is very complex, with many parts, and has many feedback mechanisms built in, both positive ones that threaten to spiral out of control, and negative ones that tend to damp out and mitigate the effects of oscillations. Which will eventually prevail is impossible to tell.

To complicate things, the climate is undergoing constant changes, both global and localized, long- and short-term, all the time due to perfectly natural causes. The role of man-made drivers is not clear.

I personally feel it is not obvious what we need to do, if anything, to solve this problem, or even if there is a long-term problem. What makes me an activist and so concerned about it, what really infuriates me, is the apparent determination of some to deny the problem might even exist, and to attack and ridicule those that are concerned about it due to their own selfish ideological and economic reasons.

Meanwhile, since you brought it up, the November numbers just came out today. We may not know exactly what is going on, or exactly what to do about it, but something IS going on, and we need to do SOMETHING about it.

http://nsidc.org/arcticseaicenews/

Average sea ice extent for November 2012 was the third lowest in the satellite record. This marks only the third year in the satellite record that November extent was below 10 million square kilometers (3.86 million square miles). Through 2012, the linear rate of decline for November Arctic ice extent is -4.8% per decade relative to the 1979 to 2000 average.

Its cold in the arctic in November, the sun is low and you expect there to be a lot of ice on the water. But it seems that every year there’s a little less, even in winter. I think its safe to say that counts as a trend. And remember, the drop in the warmest month, September, is -13% per decade.