Indicators of Global Climate Change 2022: annual update of large-scale indicators of the state of the climate system and human influence
Piers Forster, Chris Smith, Tristram Walsh, William F. Lamb, Robin Lamboll, Mathias Hauser, Aurélien Ribes, Debbie Rosen, Nathan P. Gillett, Matthew D. Palmer, Joeri Rogelj, Karina von Schuckmann, Sonia I. Seneviratne, Blair Trewin, Xuebin Zhang, Myles Allen, Robbie M. Andrew, Arlene Birt, Alex Borger, Tim Boyer, Jiddu A. Broersma, Lijing Cheng, Frank Dentener, Pierre Friedlingstein, José Marı́a Gutiérrez, Johannes Gütschow, B. D. Hall, Masayoshi Ishii, Stuart Jenkins, 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, Carl‐Friedrich Schleussner, Sophie Szopa, Peter Thorne, Robert Rohde, Maisa Rojas Corradi, Dominik L. Schumacher, Russell S. Vose, Kirsten Zickfeld, Valérie Masson‐Delmotte, Panmao Zhai
Abstract
Abstract. Intergovernmental Panel on Climate Change (IPCC) assessments arethe trusted source of scientific evidence for climate negotiations takingplace under the United Nations Framework Convention on Climate Change(UNFCCC), including the first global stocktake under the Paris Agreementthat will conclude at COP28 in December 2023. Evidence-based decision-makingneeds to be informed by up-to-date and timely information on key indicatorsof the state of the climate system and of the human influence on the globalclimate system. However, successive IPCC reports are published at intervalsof 5–10 years, creating potential for an information gap between reportcycles. We follow methods as close as possible to those used in the IPCC SixthAssessment Report (AR6) Working Group One (WGI) report. We compilemonitoring datasets to produce estimates for key climate indicators relatedto forcing of the climate system: emissions of greenhouse gases andshort-lived climate forcers, greenhouse gas concentrations, radiativeforcing, surface temperature changes, the Earth's energy imbalance, warmingattributed to human activities, the remaining carbon budget, and estimates ofglobal temperature extremes. The purpose of this effort, grounded in an opendata, open science approach, is to make annually updated reliable globalclimate indicators available in the public domain (https://doi.org/10.5281/zenodo.8000192, Smith et al., 2023a). As they aretraceable to IPCC report methods, they can be trusted by all partiesinvolved in UNFCCC negotiations and help convey wider understanding of thelatest 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 averaged over the 2013–2022 decade and 1.26 [1.0 to 1.6] ∘C in 2022. Over the 2013–2022 period, human-induced warming hasbeen increasing at an unprecedented rate of over 0.2 ∘C perdecade. This high rate of warming is caused by a combination of greenhousegas emissions being at an all-time high of 54 ± 5.3 GtCO2e overthe last decade, as well as reductions in the strength of aerosol cooling.Despite this, there is evidence that increases in greenhouse gas emissionshave slowed, and depending on societal choices, a continued series of theseannual updates over the critical 2020s decade could track a change ofdirection for human influence on climate.