Total fossil carbon dioxide emissions are projected to be at a record high of 36.8 billion tonnes in 2023, as outlined in the annual Global Carbon Budget released at the United Nations Conference of the Parties (COP28) in Dubai.
While many countries are succeeding in reducing or slowing carbon dioxide emissions, recent progress is not fast enough or widespread enough to put global emissions on a downward trajectory towards net zero, the international report found.
Dr Pep Canadell, Executive Director of the Global Carbon Project and a Chief Research Scientist at Australia’s national science agency, CSIRO, is an author of the Global Carbon Budget.
He said the annual analysis indicated that if current global carbon dioxide emission levels persist, there was a one-in-two chance the Earth’s climate system would reach 1.5°C above pre-industrial levels in about seven years.
The Paris Agreement commits to pursuing efforts to limit global warming to 1.5°C above pre-industrial levels.
“The latest Global Carbon Budget shows progress in an increasing number of countries but faster, larger, and sustained efforts are needed to avoid significant negative impacts of climate change on human health, the economy, and the environment,” Dr Canadell said.
“If the temperature targets of the Paris Agreement are crossed, the global effort to reach net zero emissions will require a massive, and perhaps unachievable, scale-up of deliberate carbon dioxide removal to bring down global temperatures.”
Global emissions from fossil fuel use are projected to rise 1.1 per cent in 2023, reaching 36.8 billion tonnes of carbon dioxide.
Emissions from all fossil sources (coal, oil, gas) are projected to increase, with the highest growth from oil, projected to rise 1.5 per cent. The growth in oil emissions is largely due to resumption of ground transport and aviation following the shutdowns during the COVID-19 pandemic.
Coal emissions, which represent 41 per cent of global emissions, are projected to increase 1.1 per cent.
Emissions from permanent forest loss through deforestation remain too high to be offset by current CO₂ removals from reforestation or afforestation.
What’s new in the 2023 Global Carbon Budget?
- The extreme fire season in the northern hemisphere has led to carbon dioxide emissions from wildfires being presented in the budget for the first time. The extreme fire season in the northern hemisphere, particularly fires in Canada, counteracted an observed decline in emissions from fires in tropical regions and drove carbon dioxide emissions higher than the global average since satellite records began in 2003. Global emissions from fires for January-October 2023 were 10-28 per cent above the 2003-2022 average.
- The 2023-24 El Niño event will further increase carbon dioxide concentrations in the atmosphere. An El Niño event brings hotter, drier weather. The Global Carbon Project anticipates that El Niño event will mean terrestrial natural carbon sinks are less effective in taking up of carbon dioxide from the atmosphere and leading to higher atmospheric carbon dioxide concentration and warming. Hotter and drier conditions in most of the tropics lead to a decline in their carbon sink strength. The ocean sink usually increases during El Niño years but does not completely offset the decline in the land sinks.
- Carbon dioxide removal, while small, is accounted for the first time in the budget. Carbon dioxide removal is where deliberate, human activity takes carbon out of the atmosphere. The budget says carbon dioxide removal from afforestation and reforestation accounted for 1.9 billion tonnes of carbon dioxide, equivalent to about 5% of fossil emissions. Carbon removal not based on vegetation (industrial removal and the use of certain minerals) was responsible for offsetting only several thousand tonnes in 2023.
What is the Global Carbon Budget?
The Global Carbon Budget provides detailed information about the natural and anthropogenic sources and sinks of carbon dioxide worldwide and is produced through peer-reviewed scientific papers.
The Global Carbon Budget was first produced in 2006 to establish a common and mutually agreed knowledge base on greenhouse gases in the atmosphere. It is an international research project within the Future Earth research initiative on global sustainability and a research partner of the World Climate Research Programme.
The Global Carbon Budget has contributed to the first Global Stocktake to be released at COP28.
The analysis is also an important input to the Intergovernmental Panel on Climate Change (IPCC) and the World Meteorological Organization (WMO), which reports on climate change caused by human activities.
Key concepts in the Global Carbon Budget
Carbon dioxide is the most significant greenhouse gas contributing to human-induced global warming, followed by methane and nitrous oxide.
Anthropogenic or human-induced carbon dioxide emissions are carbon dioxide emissions created or exacerbated as a result of human activity. For example, burning fossil fuels emits carbon dioxide into the atmosphere, while deforestation removes trees that would absorb carbon dioxide.
Global carbon cycle: The natural geological, biological and physical process in the Earth that has occurred for millions of years, where carbon naturally flows in and out of the land, ocean, and atmosphere; now altered by human activities.
Net zero emissions: Human society will have reached net zero emissions when any carbon dioxide released into the atmosphere is balanced by an equivalent amount being removed. It is a condition to stop global warming.
Net-Negative emissions: After net zero is reached, more greenhouse gases are removed than added to the atmosphere globally, which would allow humanity to cool the planet and begin restoring the atmosphere.
Fossil CO₂ emissions are created through burning and use of fossil fuels such as coal, oil and natural gas. Carbon dioxide emissions from cement production are also included in this category.
Net CO₂ emissions from land-use change refers to emissions from land-use, land-use change and forestry, such as deforestation, minus the carbon dioxide removals from e.g., re/afforestation, and forest management.
Total CO₂ emissions combine fossil carbon dioxide emissions and land-use change emissions.
The crossover, also called the overshoot, refers to missing a given temperature target, such as the 1.5°C Paris Agreement target.
Natural carbon sinks: The land and ocean take up anthropogenic carbon dioxide emitted to the atmosphere, called carbon dioxide sinks. The land and ocean take up around half of the carbon dioxide emitted into the atmosphere as a result of human activity.
Carbon dioxide removal is where historic and ongoing contributions of carbon dioxide are actively removed from the atmosphere.
Afforestation: Planting trees where there previously haven’t been trees or forests.
Reforestation: Replanting trees and forests that have previously been removed.