Enable internal variability analyses based on 0.8 and 1.2 C warming

[Tianchi-Liu]

Summary of changes and related issue

• TODO
  • Update backend in Updates for analyses in internal variability notebook climakitae#470
  • In cell 4, specify warm_level as 0.8 or 1.2, and review the notebook

Relevant motivation and context

Current options are future facing at 1.5, 2, and 3 C. Present-day options may augment the analyses.

Type of Change

• Bug fix
• New feature or notebook
• Breaking change
• Documentation update

Checklist

• The introduction of the notebook explains the purpose and expected outcome / use of the notebook
• Incorporates reference to any appropriate Guidance material
• Markdown reviewed and vetted by someone else
• Error messages for areas that might expect common user error
• Verbose and non-verbose modes function
• It may not be required for notebooks that explicitly don’t need this functionality
• List notebook overall runtime text
• Clear expectations of outcomes learned (key takeaway messages) provided