2023 Was the Hottest Year on Record: Scientific Report

It’s official. Scientists have confirmed that 2023 was the hottest calendar year since records began in 1850. The combination of human-induced climate change as well as natural events like El Nino has caused Earth’s temperature to continue to rise over the last calendar year. The Copernicus Climate Change Service, implemented on behalf of the European Commission with funding from the EU, declared this record in early January 2024.

The year 2023 recorded a 14.98℃ global average temperature, which is 0.17℃ higher than the previous 2016 record.

What Caused 2023 To Be the Hottest Year Ever?

The continued release of greenhouse gas emissions (GHG) into the atmosphere significantly contributes to global warming. It is no surprise that 2023 recorded the highest levels of GHG. The significant contributing factors to the excessive GHG concentrations are society's energy production, transportation, and industry, primarily based on fossil fuels. The major greenhouse gases used include carbon dioxide, methane, halogenated compounds, tropospheric ozone, and nitrous oxide.

Carbon dioxide emission is responsible for about 53% of global warming, and the sources include processes like deforestation, cement production and fuel use. For the worldwide residency time of greenhouse gases, about 80% persists in the environment for 200 years, and the remainder takes about 30,000 years to dissipate. Methane accounts for about 15% of global warming. It is generated from livestock production, agriculture, and natural gas production. Nitrous oxide primarily comes from fuel combustion, fertiliser, and sewage treatment, contributing to around 11% of global warming.

El Nino is a natural warming of sea temperatures that occurs once every few years. It is declared when sea temperatures rise above the long-term average by more than 0.5℃ in the tropical eastern Pacific. In 2023, El Niño conditions began to develop in July, while the global average sea surface temperatures remained persistently high. This caused marine heatwaves around the world, including parts of the Mediterranean, Indian Ocean, North Pacific, much of the North Atlantic, Gulf of Mexico, and the Caribbean. However, El Niño alone does not conclusively explain the worldwide increase in the ocean surface temperature.

What Happens When the Planet Gets Hotter?

The Intergovernmental Panel on Climate Change (IPCC) warns that society must reduce greenhouse gas emissions and limit global warming to 1.5 to mitigate catastrophic effects on people and the environment. The latest IPCC report indicates the severity of the dangers posed by excessive GHG emissions and the warming of the planet.

There is a risk to water supplies because as temperatures rise, melting glaciers and disrupted precipitation patterns lead to shortages and conflicts on water resources. Climate change worsens existing tensions over energy, water, and land. It can displace populations commonly known as climate migrants who seek refuge due to extreme weather events and environmental degradation. Excessive rise in temperature causes changes in seasonality and weather patterns, thus altering the timing of natural events such as migration, hibernation, and flowering. Excessive ambient temperature increases cause heat stress that significantly endangers human health, especially vulnerable populations such as older adults and children. Excessive temperature rises can alter climate conditions that are averse to food production and availability and impact crop yields. Global warming can exacerbate drier conditions and droughts, contributing to wildfires and forest die-offs. Wildfires, in particular, were rampant throughout 2023, with Canada recording the most devastating wildfire season in history.

Could 2024 Be Even Hotter?

The 2023 weather events have raised the possibility that 2024 could be warmer than previous years and surpass the 1.5 global warming threshold set by the IPCC. This threshold aligns with the ambitious targets of the Paris Agreement. Our article on the Paris Agreement sets out its key aims and what action needs to be taken in order to beat the current climate crisis.

The Paris Agreement focuses on long-term temperature recording averages over 20-30 years. As a result, a year or two's increase does not necessarily hinder the agreement's ambitions. Instead, it warns of the current trajectory risk that, if it continues, would jeopardise the future of our planet.

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About the Author 

Enock Ebbah MSc has a wealth of combined experience, having spent 13 years developing and delivering energy, environment and sustainability projects, energy research and responsible engineering. His specialist expertise in strategic NetZero solutions, energy transition, decarbonisation initiatives, and sustainable approaches to using energy, materials, and resources for sustainable development. As an Environment and Sustainability Consultant at Astutis, Enock helps organisations deliver ambitious environment, sustainability, and NetZero outcomes by providing environmental assessments, environmental and sustainability training, ESG materiality assessments, and sustainability reporting and strategy.