Arctic is warmest it's been in 10,000 years

[classicdrogn]

Here's another set of supporting data - apparently the amount of atmospheric CO2 is the highest it's been in the better part of a million years, as determined from ice cores and the history of direct measurements. How much higher? Looking a these graphs, it's nearly double the long term mean.




(aggregator site) source
academic site providing the actual graphs
second article quoted by the BGR story, and below.

The rise in CO2 is unambiguously caused by human activity, principally fossil-fuel burning. This is clear from the numbers: We know how much fossil fuel is converted into CO2 each year and emitted into the atmosphere. The CO2 doesn’t all stay there because some enters the ocean and some is taken up by photosynthesis, which ends up in land plants and various types of biomatter.

Carbon atoms are not created or destroyed in any of these processes, so the total fossil-fuel emission to date must equal the combined increases in these other reservoirs. We can document large carbon increases in all these reservoirs. In the atmosphere, it’s especially easy, because the atmosphere is quite well mixed. As it happens, about 57 percent of the emissions have remained in the air.

It’s true that atmospheric CO2 has almost certainly been higher than present in Earth’s distant past, many millions of years ago. But because fossil-fuel burning is not natural, the recent carbon increases in the atmosphere, oceans, and land biosphere cannot be natural either. And you are correct that even though the levels of CO2 in the air may not be unprecedented, the pace of rise probably is. Few if any natural processes can release fossil carbon into the atmosphere as fast as we humans are doing it now via the extraction and burning of fossil fuels.