The Changing Earth - The Medieval Warm Period and The Little Ice Age

Why can’t recent climate change just be an effect of 'natural causes'?

There have been climate changes in the past 2000 years.

People talk about times called the Medieval Warm Period and the Little Ice Age.

Careful research has shown that the current temperature rise is much bigger than the Medieval Warm Period. 
Climate scientists have discovered that the Medieval Warm Period had a number of causes.

The Sun was more active, and volcanic activity was low, which both increase warming. 

Other evidence suggests ocean currents changed, bringing warmer seawater into the North Atlantic.

When these factors changed, the Earth resumed cooling, creating the Little Ice Age.

The Industrial Revolution, when coal burning began on a large scale, started the recent rise in temperatures, reversing the cooling trend.

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