Human-Induced Global Warming Hits 1.19°C Over the Past Decade: Report

The second annual Indicators of Global Climate Change report, led by the University of Leeds, reveals a significant rise in human-induced warming. Over the past decade (2014-2023), this warming has increased to 1.19 °C, up from 1.14 °C observed during 2013-2022. When examining 2023 specifically, the warming due to human activities reached 1.3 °C. However, the total warming for that year was 1.43 °C, suggesting that natural climate variability, particularly the influence of El Niño, also contributed to the record temperatures experienced.  

The report highlights a critical concern regarding the remaining carbon budget—the amount of carbon dioxide that can be emitted before committing to 1.5 °C of global warming. This budget stands at approximately 200 gigatonnes (billion tonnes), equivalent to about five years' worth of current emissions. In 2020, the Intergovernmental Panel on Climate Change (IPCC) estimated this budget to be between 300 and 900 gigatonnes, with a central estimate of 500 gigatonnes. Since then, ongoing CO2 emissions and global warming have reduced this budget. By the start of 2024, the remaining carbon budget was recalculated to be between 100 and 450 gigatonnes, with a central estimate of 200 gigatonnes.

Professor Piers Forster, Director of the Priestley Centre for Climate Futures at the University of Leeds, who coordinates the Indicators of Global Climate Change Project, emphasized the continuous rise in global warming due to human activities. Despite efforts to curb greenhouse gas emissions, global temperatures are increasing at an alarming rate. Forster’s analysis underlines the urgency of the situation as climate experts gather in Bonn to set the stage for the COP29 climate conference scheduled for November in Baku, Azerbaijan.

While the UN’s Intergovernmental Panel on Climate Change (IPCC) serves as the primary source of scientific information on the state of the climate, its next major assessment will not occur until around 2027. This creates an “information gap” at a time when climate indicators are rapidly evolving. To address this, the new report is accompanied by an open data, open science platform called the Climate Change Tracker’s Indicators of Global Climate Change dashboard. This platform provides accessible and updated information on key climate indicators.

The latest indicator report, published by over 50 scientists in the journal Earth System Science Data, also sheds light on the effects of reducing sulphur emissions from the global shipping industry. Sulphur emissions have a cooling effect on the climate by reflecting sunlight and aiding in the formation of more reflective clouds. However, reductions in these emissions have diminished this cooling effect. Although last year's aerosol emissions from Canadian wildfires partially offset this reduction, the long-term trend shows a decline in the cooling effect from aerosol emissions.

Key findings from the report include the unprecedented rate of human-induced warming, which has risen to 1.19 °C over the past decade, an increase from the previous 1.14 °C. This warming is occurring at approximately 0.26 °C per decade, driven by consistently high greenhouse gas emissions, which total about 53 billion tonnes of CO2 annually, and improvements in air quality that reduce cooling from atmospheric particles. High greenhouse gas emission levels are also impacting the Earth's energy balance. Ocean buoys and satellites are monitoring unprecedented heat flows into the Earth's oceans, ice caps, soils, and atmosphere, with this heat flow being 50% higher than the long-term average.

The report aims to play a crucial role in shaping new Nationally Determined Contributions. These enhanced climate plans, which every country has pledged to present to the United Nations Framework Convention on Climate Change (UNFCCC) by 2025, are essential for cutting emissions and adapting to climate impacts. 

As the world continues to grapple with the accelerating pace of climate change, the "Indicators of Global Climate Change" report serves as a crucial tool for policymakers and scientists alike.