Indicators of Global Climate Change 2022: annual update of large-scale indicators of the state of the climate system and human influence
Authors: Forster Piers M. , Smith Christopher J. , Walsh Tristram , Lamb William F. , Lamboll Robin , Hauser Mathias , Ribes Aurélien , Rosen Debbie , Gillett Nathan , Palmer Matthew D. , Rogelj Joeri , von Schuckmann Karina , Seneviratne Sonia I. , Trewin Blair , Zhang Xuebin , Allen Myles , Andrew Robbie , Birt Arlene , Borger Alex , Boyer Tim , Broersma Jiddu A. , Cheng Lijing , Dentener Frank , Friedlingstein Pierre , Gutiérrez José M. , Gütschow Johannes , Hall Bradley , Ishii Masayoshi , Jenkins Stuart , Lan Xin , Lee June-Yi , Morice Colin , Kadow Christopher , Kennedy John , Killick Rachel , Minx Jan C. , Naik Vaishali , Peters Glen P. , Pirani Anna , Pongratz Julia , Schleussner Carl-Friedrich , Szopa Sophie , Thorne Peter , Rohde Robert , Rojas Corradi Maisa , Schumacher Dominik , Vose Russell , Zickfeld Kirsten , Masson-Delmotte Valérie , Zhai Panmao 
Published: June 2023

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 follow methods as close as possible to those used in the IPCC Sixth
Assessment Report (AR6) Working Group One (WGI) report. We compile
monitoring datasets to produce estimates for key climate indicators related
to forcing of the climate system: emissions of greenhouse gases and
short-lived climate forcers, 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.8000192, Smith et al., 2023a). As they are
traceable to 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 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 has
been 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 54 ± 5.3 GtCO2e over
the last decade, as well as reductions in the strength of aerosol cooling.
Despite this, there is evidence that increases in greenhouse gas emissions
have slowed, and depending on societal choices, a continued series of these
annual updates over the critical 2020s decade could track a change of
direction for human influence on climate.