HadCRUT5-20CRv3 comparison

At the top, the extended stripes from HadCRUT5. In the middle, the extended stripes from 20CRv3. At the bottom, the difference between them (HadCRUT5-20CRv3).

• Function to extract the HadCRUT5 data sample
• Function to extract the 20CRv3 data sample
• Function to extract the difference data sample
• Script to make the plot