Yep, Milankovich cycles are what causes the ice age cycles. Here's a graph based on ice cores::
https://www.ncdc.noaa.gov/global-warmin ... ure-changeThe cycles are lots longer than 5000 years, and many times more longer than the warming experienced over the last 100 years. Not only that, but if our climate were being driven primarily by the Milankovich cycles, we'd be slowly cooling, not rapidly heating.
I think what Dan may have been thinking of is what's called the Mid-Holocene Warm period. Here's what the NOAA web page has to say about it:
Paleoclimatologists have long suspected that the "middle Holocene," a period roughly from 7,000 to 5,000 years ago, was warmer than the present day. Terms like the Altithermal or Hypsithermal or Climatic Optimum have all been used to refer to this warm period that marked the middle of the current interglacial period. Today, however, we know that these terms are obsolete and that the truth of the Holocene is more complicated than originally believed.
What is most remarkable about the mid-Holocene is that we now have a good understanding of both the global patterns of temperature change during that period and what caused them. It appears clear that changes in Earth's orbit have operated slowly over thousands and millions of years to change the amount of solar radiation reaching each latitudinal band of Earth during each month. These orbital changes can be easily calculated and predict that the Northern Hemisphere should have been warmer than today during the mid-Holocene in the summer and colder in the winter. The combination of warmer summers and colder winters is apparent for some regions in the proxy records and model simulations. There are some important exceptions to this pattern, however, including colder summers in the monsoon regions of Africa and Asia due to stronger monsoons with associated increased cloud cover during the mid-Holocene, and warmer winters at high latitudes due to reduction of winter sea ice cover caused by more summer melting.
In summary, the mid-Holocene, roughly 6,000 years ago, was generally warmer than today during summer in the Northern Hemisphere. In some locations, this could be true for winter as well. Moreover, we clearly know the cause of this natural warming, and we know without doubt that this proven "astronomical" climate forcing mechanism cannot be responsible for the warming over the last 100 years.
https://www.ncdc.noaa.gov/global-warmin ... arm-periodAnd here's a graph from data published in the leading article that used proxies to estimate global temperatures over the last 11,000 years:
http://www.realclimate.org/index.php/ar ... -holocene/Data from:
http://science.sciencemag.org/content/339/6124/1198The blue line is the reconstructed temperature. The red line is the measured temperature. Note that the anomaly in that graph is .4. Today it's about 1.0.
So, it's doubtful that global temperatures during the Mid-Holocene warming period exceeded those of today. But even if they did, the margins were talking about are tenths of a degree -- not five or six degrees. And on top of that, the Milankovich cycles cannot explain the current global warming.
“The ideal subject of totalitarian rule is not the convinced Nazi or the dedicated communist, but people for whom the distinction between fact and fiction, true and false, no longer exists.”
― Hannah Arendt, The Origins of Totalitarianism, 1951
