XKCD's climate change timeline showing human impact

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mfb said:
Deviations from those cycles are slow.

Slower than annual, yes. But there is still plenty of evidence that the key processes involved change significantly on time scales much shorter than 1 kyr. For example, the following papers all describe significant changes in primary CO2 production in the ocean due to biological processes on time scales of a few decades:

http://www.sciencedirect.com/science/article/pii/S0079661115000993

http://onlinelibrary.wiley.com/doi/10.1029/2010GB004026/full

https://www2.cgd.ucar.edu/sites/default/files/asp-colloquium/files/Chavez-Messie-etal-2011.pdf

http://onlinelibrary.wiley.com/doi/10.1029/2010GB004026/full

Also, rates of upwelling are known to vary significantly on decadal timescales (I don't have any links handy at the moment but can find some if desired).
 
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mfb said:
Where is your point?
All those natural processes are slow. "<1kyr" is called "fast" already, the ice ages are even slower. Those natural changes are completely different from the change we had in the last 100 years.

Keeping in mind the idea that IPCC states about CO2 levels lagging behind temperature changes by a couple hundred years, there are a few factors that are compounding right now:
  • The timing of the end of the mini ice age (sometime around the 1800s, although I don't know of an exact consensus on its end date)
  • The carbonic uptake and storage during the mini ice age created a reservoir that has been being released in the past 100 years
  • The warming that occurred in recovery from the mini ice age (solar energy output increasing)
  • The long-term interglacial warming patterns which indicate that the Earth is scheduled to encounter long term warming trends right now regardless of recovery from mini ice age.
  • Feedbacks created by these affects.
  • Anthropological contributions (This list is primarily concerned with natural forcing, but I included this one as a gesture of solidarity and acknowledgment. I am making no claims about the extent to which this does or does not impact the climate.)
We're also discussing a sample of data that is measured with more certainty and resolution than is attainable while measuring temperature retroactively to the last time Earth has been at this point in an interglacial cycle.
 
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DrClaude said:
Because this is the main driver of the current climate change

It might be more appropriate, given the PF rules on this specific topic, to say that the IPCC reports, and the scientific research they are based on, conclude that CO2 is the main driver of the current climate change. That way the source you are relying on is clear.
 
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Ultimately this thread does not meet our guidelines for discussion. If there are tangent discussions left unresolved feel free to start a new thread using peer reviewed sources. Closing up. Thanks!