How does one erase 300 years of inconvenient warming?

From the Climategate 2.0 e-mail collection, someone named Pollack (possibly alarmist Henry Pollack)

But it will be very difficult to make the MWP [Medieval Warm Period] go away in Greenland.

The chart below from the IPCC First Assessment Report in 1990 shows why alarmists want to erase the MWP.

Read Climategate 2.0.