• The global climate system is stable and slow.
• Climate change is underway.
  Warming since the beginning of the industrial era: 0.8 - 1 °C
  on average: 0.5 °C per century, with accelerations and decelerations over a 60-year cycle.
• Only a portion of the warming can be attributed to GHGs, including CO₂.
  The rest must be explained by the continuation of the exit of the little ice age and by other mechanisms, natural or artificial.
• Anthropogenic GHG emissions are real.
  ~45% of the CO₂ emitted accumulates in the atmosphere and the rest is sequestered in biomass and in the oceans.
• General circulation models have not been validated; there is no confidence in any projection made with them.
• We need centuries of observation to understand climate variations.
  No modelling can accelerate this knowledge.

CO₂ is a modest cause of a poorly defined problem
whose reduction contributes little or nothing to its improbable solution.