Global Warming - How unusual is the rise in Earth's temperature?

The last major glacial stage of the "Ice Age" ended thousands of years ago.

Since the ice melted back, the temperature has not been totally fixed, but the recent rise is very different.
The graph shows that after the ice melted, temperatures continued to rise for a few thousand years.
Around 8,000 years ago the global temperature steadied (with some 'wiggles') until about 4,000 years ago.
Then the Earth began to cool slowly, and that continued until modern times, with some variations.

 These conditions have been stable enough to allow successful agriculture.

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