While the „denialosphere” is desperately trying to develop just-another-misunderstanding of climate science (search for “global warming stopped” meme), there is another *real* issue. Specifically, the last time planet Earth enjoyed carbon concentration at around 400 ppm for a longer time period, average summer temperatures in the Arctic region were significantly higher.
According to the latest and most comprehensive paleoclimatic analysis, which brought us high resolution temporal data back to the Pliocene (Brigham-Grette et al., 2013, Science), summer temperatures in NE Arctic region were ~8 °C higher compared with present-day climatology.
There are tree recent paleoclimatic temperature reconstructions from the Arctic region. Two of them are presented in the following graph:
The fit of the two paleo-reconstructions is not perfect, but the trends are similar and warmer, as well cooler periods in the past can be observed – the well known “Little Ice Age” and “Medieval Warm Period”. The recent “hockey stick” is also familiar to most people engaged in climate change discussion, since a similar trend is valid for the whole Nothern hemisphere and the planet.
But there is more. What we already knew is that as CO2 concentration continue to rise, global temperatures will do the same. The arctic region will warm even faster. Maybe some positive feedback loop will kick in. Maybe even more than one. But now things look even more complicated, since the recent work of Brigham-Grette et al. (2013) has shown us, what the area around the lake El’gygytgyn in the NE Arctic Russia (and by proxy also most of he Arctic) looked like last time, when CO2 concentration was approximately at the present level. Watch out:
Still concerned only about polar bears? This article was originally published at Neven's Arctic Sea Ice Blog. There is also another excellent representation of human extremely complex influence on planet Earth, which many call "The Anthropocene", not without a reason!
(h/t Jozef Pecho)
A comment by Ugo Bardi: The decline of Arctic ice is probably the most visually evident consequence of global warming. It is clear, obvious, impressive: no one can miss it. And with the troubles of the polar bears, you would think that no one could remain indifferent. You would think that a well argued and well researched article such as this one by Alexander Ac would have some effect.
Yet, the accumulating evidence fails to make a dent in the general indifference. News about the polar melting appear in the media, but they fail to generate a reaction: most people seem to be immune to memetic infection from Arctic news. In large part, this lack of reaction is due to the "Star Wars Force Push" effect. As Peter Sandman states, people react to emergencies in way that are far from being rational: "When somebody says something that people don’t want to hear – and certainly don’t want to have to think about or acknowledge – they sometimes self-mockingly stick their fingers in their ears and sing, “La-la-la-la-la.” This is a very literal representation of the essence of denial."
So, it is not enough to place the evidence in front of people: most of the times, they will just ignore it. Even if the canary dies, they'll keep mining.