March 21, 2023

An updated climate change report has been released by the IPCC. This is essentially the final Synthesis report that will be released before we warm the world over the 1.5C threshold.

The importance of this report cannot be overstated. It sets the foundation for the current climate change analysis, adaptation investments, response/preparedness investments, and general policies.

Some terms:

IPCC

Intergovernmental Panel on Climate Change

AR6

6th Assessment Report (the latest models)

Synthesis Report

latest full analysis report (released March 20, 2023)

1990

The CO2 emission base year we are trying to return to.

Working Group I

Physical Sciences (234 authors, 14000 citations)

Working Group II

Impacts, Adaptation, and Vulnerability (270 authors)

Working Group III

Mitigation (239 authors)

SPM

Summary for Policymakers (of the Synthesis Report)

NDC

Nationally Determined Contributions. What countries intend to achieve.

LULUCF

Land use, land-use change, and forestry

SSP1

1.5°C Shared Socioeconomic Pathways

SSP3

3.6°C The do nothing Shared Socioeconomic Pathways (not unlike what we are doing now.)

Because it is so important, it is a long document and the entire document has not been released yet. Only the summaries have been released.

• Here is the policy summary. It is written in a style particular to the IPCC process which means it is both difficult to read but also very clear in its statements.
• Here are the graphics in the Summary.

Main takeaways:

1. There is a large gap between where we need to be and what has been promised by governments.
2. There is a much larger gap between where we need to be and what we are actually doing.
3. The IPPC original target of limiting global warming to 1.5°C increase above recent historical averages looks to be impossible.
4. The focus of this Synthesis report is on the impacts of 2°C.
5. Current NDC policies put us on the path to 2.2°C to 3.5°C of warming.
6. The current realities put us above the NDC policy model as countries are not reaching their Paris Agreement NDC targets.
7. The 1.5°C goal meant that emissions needed to decline by about 45% from the 2010 level by 2030, reaching net zero around 2050.
8. Net Zero is not enough, carbon must be removed from the atmosphere by some yet to be determined process in addition to reaching Net Zero by 2050.
9. The previous reports show that land use for agriculture are not on the list of priorities for carbon reduction. Food production and land use continue to be priorities for adaptation.
10. The updated risk assessments indicate most of the terrible things will happen at lower temperature increases than thought.

Nationally Determined Contributions. This from the 2021 IPCC study:

The next graphics are from the current Summary Report of AR6. You will notice that there is a large "error" term around the predictions. As with all models, the path could be much worse or less bad than the average path.

The ranges of 1.5°C and the 2°C paths overlap a little. This has lead to some suggesting that 2°C paths are the same as 1.5°C. The problem with that analysis is that were are no where near even the 2°C path, never mind the 1.5°C.

Only the 1.5°C guarantees a planet that is sustainable for human life.

This is not something to leave to chance. What is the point of implementing solutions if there is a chance of everything we are doing still resulting in an unlivable planet?