Pricing mitigation efforts and assessing the difficulties of comparison
Key points
- The present global consensus to reduce greenhouse gas emissions to net zero will require immense investment
- Investment spending is not a cost but will boost activity. Costs will reflect increased production costs, taxes and regulations associated with reducing emissions
- A range of supra-national institutions estimate global GDP to be between +2.5% to -2% by 2050 after climate change mitigation actions. The cost of unmitigated climate change is estimated at a larger range of 3% to 30% of global GDP by 2100. The cost of global warming in the most conservative scenario is thus higher than the mitigation cost in the most pessimistic scenario.
- A comparison of the two is complicated by near-term costs and far-distant benefits. The use of lower discount rates seems appropriate, which adds to arguments for intervention
- Differences will also occur across geographies, making a global comparison of costs different from individual assessments by countries and regions