A brief guide to the IPCC Synthesis Report, Part A

This piece provides a summary of the latest IPCC synthesis report based on their sixth Assessment Report (AR6).

Given that even the relatively short ‘summary for policy makers’ is not an easy read, here we attempt to draw out the basic information about where we currently are. None of these points will surprise anyone but having them to hand in this way will we hope be useful. Note that this piece deals only with section A of the report, covering the current state of the climate. A further blog will cover parts B and C, which are about modelling to project likely scenarios for the long and short-term respectively.

Headline figure

Average global temperature for 2011-2020 is 1.1 o C above that for 1850-1900.

IPCC is unequivocal about the primary role of human activity in this increase; the contribution ascribed to ‘natural’ drivers is between -0.1 o and +0.1 o C.

Emissions since 1850 = 2400 GtCO 2 42% of that figure has been emitted since 1990.

CO 2 parts per million in the atmosphere is 410, the highest for >2million years.
Methane and NOx levels are highest for 800,000 years.

GHG emissions in 2019 are 12% higher than in 2010, and 54% higher than 1990.
The decade 2010-2019 has the highest absolute emissions, but the growth rate has been lower than for 2000-2009.

2019 emissions were:

79% from the energy, industry, transport and building sectors.
22% from agriculture, forestry and other land use.
(Presumably the 1% discrepancy is rounding.)

The crucial point is that emissions reduction efforts were outweighed by increases during the last decade.

Global distribution

(on a CO 2 -eq per capita basis)
Global average = 6.9t per person
35% of population = above 9t
41% of population = below 3t
Least Developed Countries populations – 1.7t
Top 10% of global population contributes 34-45% of emissions.
Bottom 50% = 13-15%

Changes in sea level rise

1901-1971 = 1.3mm per annum
1971-2006 = 1.9 mm p.a.
2006-2008 = 3.7mm p.a.

Highly vulnerable to mortality and illness attributable to climate change = 3.3-3.6 billion people.

Covers Africa, Asia, Central and South America, Least Developed Countries (LDCs), Small Islands, the Arctic, along with indigenous people and low-income households everywhere.

Ecosystem degradation approaching irreversibility in a number of regions, particularly permafrost thaw in the Arctic.

Reduced food and water security is hindering efforts to meet UN Sustainability Development Goals. Half the world experiences severe water scarcity for at least part of the year.

Extreme heat has led to increased food- and water-borne diseases, mental health issues and trauma, loss of livelihood and culture.

Adverse impacts, unequally distributed, include damage to industry and services, destruction of homes and infrastructure, effects on gender and social inequalities.

Adaptation

Planning and implementation has progressed, and shown benefits, but with varying effectiveness. Gaps exist and will grow at current implementation rate. Limits of adaptation reached in some regions.

Global financial flows are preventing implementation, especially in LDCs, due to:

• Insufficient funds,
• Low climate literacy,
• Lack of political commitment,
• Low sense of urgency.

Gap between cost of adaptation and finances allocated is widening.

Green energy is technically viable and reducing in cost. In some regions transitioning to green energy is cheaper than maintaining emissions-intensive systems. A shortfall in meeting commitments made at Kyoto, Paris and Glasgow make keeping to 1.5 o C unlikely.

Deep reductions in emissions are required during the 2020s to keep below 2 o C by 2100. Median scenario, if all pledges are kept, is 2.8 o C by 2100. Net zero pledges have limited policies to deliver on them. The implementation gap suggests a median scenario of 3.2 o C by 2100.

Tahir Latif
Secretary, Greener Jobs Alliance
March 2023