Global Carbon Budget 2023

It is not enough to subsidize clean energy, policies are also needed to reduce fossil fuel use.

Despite record growth in clean energy, global fossil CO2 emissions are expected to grow 1.1% [0-2.1%] in 2023. Strong policies are needed to ensure fossil fuels decline as clean energy grows!

The Global Carbon Budget 2023 is now published in ESSD, with a website, figures with data, & full dataset of the carbon budget. This year there were 121 people directly involved from 95 organisations and 17 countries. The broader network of people indirectly contributing is probably in the thousands.

CICERO compiles the fossil CO2 emissions data, both historical and future projections.

The key messages by fossil fuel:

• We thought coal peaked in 2014. No, & up another 1.1% in 2023

• Oil up 1.5%, on the back of a 28% increase in international aviation but remains below 2019 level

• Has the golden age of gas come to an end thanks to Russia?

We do projects for the biggest four emitters:

• China up 4.0% & a peak would be a surprise

• US down 3.0%, with coal at 1903 levels

• India up 8.2%, with fossil CO2 clearly about the EU27

• EU27, down 7.4% with drops in all fuels

• For the first time, we separate out bunkers, up 11.9% due to exploding aviation

The biggest four emitters do not have the highest per capita emissions:

• China’s per capita emissions are almost twice the global average & four times India

• The US is three times the global average

• India is less than half the global average

Other than India, the largest emitters are all above the global average

There is a lot of talk about peak emissions this year. I am not really sure why. But, are we at peak CO2 emissions?

• Fossil CO2 emissions are clearly growing, 0.5% per year over the last decade, down from ~3% the decade before.

• Land-use change CO2 emissions have a slight but uncertain decline

• When these two are added, total CO2 emissions are growing at 0.14% per year in the last decade, down from ~2% the decade before

• Total CO2 emissions are a record high in 2023, but almost the same value as in 2023

No. I don’t think we are at peak CO2 emissions. Of course, emissions may peak in 2023, but that requires a dramatic change or some luck!

Land-use change CO2 emissions are a mix of sources and sinks:

• Total deforestation is fairly flat in the last 10 years

• Total regrowth (e.g., afforestation) is what gives LUC a negative trend over the last decade

• These estimates are based on three bookkeeping models, which give different trends over the last decade.

Clearly, we need to stop deforestation!

With all this CO2 going into the atmosphere, we expect the atmospheric CO2 concentration to go up 2.4 parts per million (ppm), which is the same as the decade trend. El Nino effect likely to be more pronounced in 2024.

The Global Carbon Budget is the balance between:

• Sources: Fossil & LUC emissions

• Sinks: Ocean & land uptake, atmospheric

There is a small imbalance, which is the difference between independent estimates of the carbon budget. Our goal is to reduce the imbalance with better data and models.

The land and ocean sinks continue to take up 55% of the CO2 we put in the atmosphere. What a discount!

Though, we do see that sinks are being effected by climate change.

Global CO2 emissions continue to track in the middle of the range of SSP-based scenarios (developed around 2015). Perhaps this means the scenarios were just good at spanning the range?

It is hard to estimate where we are going. While we may be “tracking” SSP2-45, that does not mean we will track it for the next 75 years. We still have plenty of ability to bend the curve, and ensure we go well below SSP2-45.

The figure includes latest (2023) CO2 estimates & AR6 temperature projections (far right).

This is just a quick summary of the global carbon budget for 2023. Over the coming days, weeks, month, much more content will be shared.