Fossil CO2 emissions at record high in 2023, study shows

Global carbon emissions from fossil fuels have risen again in 2023 – reaching record levels, according to new research from the Global Carbon Project science team.

The annual Global Carbon Budget, which was produced with the expertise of a University of Reading climate scientist, projects fossil carbon dioxide (CO2) emissions of 36.8 billion tonnes in 2023, up 1.1% from 2022.

Dr Patrick McGuire, land surface processes expert at the University of Reading and National Centre for Atmospheric Science (NCAS), improved and ran simulations to understand the impact of changing the representation of both land-use change and tree and crop harvest on carbon emissions.

He said: “The amount of carbon dioxide released from burning fossil fuels is going down in some areas like Europe and the United States, but it is still increasing overall around the world. All countries need to take much stronger action to transition from fossil fuels to clean energy. If we don't speed this up, climate change will bring very harmful impacts all over the world.

“Deforestation releases more carbon dioxide than is being absorbed by the current level of replanting. More effort is needed to protect existing forests and plant new ones to help absorb some of the extra carbon dioxide in the air.”

1.5c threshold

The report projects that total global CO2 emissions (fossil + land-use change) will be 40.9 billion tonnes in 2023. This is about the same as 2022 levels, and part of a 10-year “plateau” – far from the steep reduction in emissions that is urgently needed to meet global climate targets.

The study also estimates the remaining carbon budget before the 1.5°C target is breached consistently over multiple years, not just for a single year. At the current emissions level, the Global Carbon Budget team estimates a 50% chance global warming will exceed 1.5°C consistently in about seven years. This estimate is subject to large uncertainties, primarily due to the uncertainty on the additional warming coming from non-CO2 agents, especially for the 1.5°C targets which is getting close to the current warming level. However, it’s clear that the remaining carbon budget – and therefore the time left to meet the 1.5°C target and avoid the worse impacts of climate change – is running out fast.

Other key findings from the 2023 Global Carbon Budget include:

• Regional trends vary dramatically. Emissions in 2023 are projected to increase in India (8.2%) and China (4.0%), and decline in the EU (-7.4%), the USA (-3.0%) and the rest of the world (-0.4%).
• Global emissions from coal (1.1%), oil (1.5%) and gas (0.5%) are all projected to increase.
• Atmospheric CO2 levels are projected to average 419.3 parts per million in 2023, 51% above pre-industrial levels.
• About half of all CO2 emitted continues to be absorbed by land and ocean “sinks”, with the rest remaining in the atmosphere where it causes climate change.
• Global CO2 emissions from fires in 2023 have been larger than the average (based on satellite records since 2003) due to an extreme wildfire season in Canada, where emissions were six to eight times higher than average.
• Current levels of technology-based Carbon Dioxide Removal (ie excluding nature-based means such as reforestation) amount to about 0.01 million tonnes CO₂, more than a million times smaller than current fossil CO2 emissions.

The Global Carbon Budget report, produced by an international team of more than 120 scientists, provides an annual, peer-reviewed update, building on established methodologies in a fully transparent manner.

The 2023 edition (the 18th annual report) will be published in the journal Earth System Science Data.