Indicators of Global Climate Change 2022: Annual update of large-scale indicators of the state of the climate system and the human influence
Piers Forster, Chris Smith, Tristram Walsh, William F. Lamb, Matthew D. Palmer, Karina von Schuckmann, Blair Trewin, Myles Allen, Robbie M. Andrew, Arlene Birt, Alex Borger, Tim Boyer, Jiddu A. Broersma, Lijing Cheng, Frank Dentener, Pierre Friedlingstein, Nathan P. Gillett, José Marı́a Gutiérrez, Johannes Gütschow, Mathias Hauser, B. D. Hall, Masayoshi Ishii, Stuart Jenkins, Robin Lamboll, Xin Lan, June‐Yi Lee, Colin Morice, Christopher Kadow, John Kennedy, Rachel Killick, Jan C. Minx, Vaishali Naïk, Glen P. Peters, Anna Pirani, Julia Pongratz, Aurélien Ribes, Joeri Rogelj, Debbie Rosen, Carl‐Friedrich Schleussner, Sonia I. Seneviratne, Sophie Szopa, Peter Thorne, Robert Rohde, Maisa Rojas Corradi, Dominik L. Schumacher, Russell S. Vose, Kirsten Zickfeld, Xuebin Zhang, Valérie Masson‐Delmotte, Panmao Zhai
Abstract
Abstract. Intergovernmental Panel on Climate Change (IPCC) assessments are the trusted source of scientific evidence for climate negotiations taking place under the United Nations Framework Convention on Climate Change (UNFCCC), including the first global stocktake under the Paris Agreement that will conclude at COP28 in December 2023. Evidence-based decision making needs to be informed by up-to-date and timely information on key indicators of the state of the climate system and of the human influence on the global climate system. However, successive IPCC reports are published at intervals of 5–10 years, creating potential for an information gap between report cycles. We base this update on the assessment methods used in the IPCC Sixth Assessment Report (AR6) Working Group One (WGI) report, updating the monitoring datasets and to produce updated estimates for key climate indicators including emissions, greenhouse gas concentrations, radiative forcing, surface temperature changes, the Earth’s energy imbalance, warming attributed to human activities, the remaining carbon budget and estimates of global temperature extremes. The purpose of this effort, grounded in an open data, open science approach, is to make annually updated reliable global climate indicators available in the public domain (https://doi.org/10.5281/zenodo.7883758, Smith et al., 2023). As they are traceable and consistent with IPCC report methods, they can be trusted by all parties involved in UNFCCC negotiations and help convey wider understanding of the latest knowledge of the climate system and its direction of travel. The indicators show that human induced warming reached 1.14 [0.9 to 1.4] °C over the 2013–2022 period and 1.26 [1.0 to 1.6] °C in 2022. Human induced warming is increasing at an unprecedented rate of over 0.2 °C per decade. This high rate of warming is caused by a combination of greenhouse gas emissions being at an all-time high of 57 ± 5.6 GtCO2e over the last decade, as well as reductions in the strength of aerosol cooling. Despite this, there are signs that emission levels are starting to stabilise, and we can hope that a continued series of these annual updates might track a real-world change of direction for the climate over this critical decade.