- This week, the Intergovernmental Panel on Climate Change (IPCC) released the synthesis report of its Sixth Assessment Report (AR6) cycle, drawing together key findings from its six most recent reports.
- The report gains added legitimacy as its summary for policymakers is approved line by line by governments of the world.
- The United Nations Secretary General has called it a ‘survival guide for humanity’.
- The report can shape our collective response in this critical decade, which may be make or break for humanity, and is likely to be the last IPCC report for a few years.
- The report confirms that human activity is ‘unequivocally’ driving global temperature rise, which has reached approximately 1.1° C above pre industrial levels.
- While the rate of emissions growth has slowed in the past decade, humanity is estimated to be on a 2.8° C(2.1°3.4° C range) trajectory by 2100.
- This temperature rise has already led to rapid and widespread impacts on climatic systems.
- It flags that “For any given future warming level, many climate related risks are higher than assessed in AR5”.
- This new realisation underpins the considerable attention in the IPCC report to trajectories that constrain global warming to 1.5° C rather than 2° C.
- This relative focus on 1.5° C has two implications.
- First, the amount of carbon that the world can cumulatively emit before reaching key temperature limits, i.e., the world’s ‘carbon budget’, is far lower for the 1.5° C than the 2° C target.
- Modelled global pathways suggest that
- limiting warming to 1.5° C (with a probability of >50% requires greenhouse gas (GHG) emissions to be reduced by 43% by 2030 (median estimate),
- while the same number for limiting warming to 2° C (probability of >67%) is 21%.
- The IPCC report points out that humanity had already consumed 4/5ths of its total carbon budget for 1.5° C by 2019, with developed economies consuming the lion’s share.
- Second, the recognition of greater risks at lower temperatures points to the necessity of early climate adaptation. The report highlights that adaptation itself has limits.
So while the diagnosis is dire, what of the prognosis?
- The leading message of the report is that of urgently adopting ‘climate resilient development’ — a developmental model that integrates both adaptation and mitigation to advance sustainable development for all.
- While a climate resilient development pathway is the journey, the destination is net zero emissions at the global level.
- The report confirms the effectiveness of existing policy tools such as regulations and carbon markets.
- However, despite sufficient global capital, both adaptation and mitigation financing need to increase manyfold: between three to six times for
annual modelled mitigation investments, from 2020 to 2030.