On the nature and attribution of the 2022 annual record temperature in the UK and Ireland

As climate changes to likely a warmer mean state by the end of this century than any time during the existence of humans, the world population has rapidly increased from about 1.3 billion in 1850 to 8 billion in November 2022. The latest IPCC AR6 reports attests that extreme events (e.g., heatwaves, floods, droughts, etc.) are occurring in many parts of the world at an increasing frequency and/or intensity due to global climate change, and are threatening human health, Earth’s biosphere, and the socio‐economic fabric of our rapidly expanding and resource‐hungry civilisation. On 19 July 2022 England, Wales and Scotland all experienced the hottest days on the record reaching 40.3 deg.C, 37.1 deg.C and 34.8 deg.C, respectively, and London Fire Brigade received the highest number of emergency calls since World War II. While in Dublin near-surface air temperature reached 33.0 deg.C on 18 July – the highest in the Ireland’s record. Furthermore, the annual mean temperature in 2022 was highest on the record in the UK and Ireland. This study uses a set of observations and reanalysis products combined with large ensembles of CMIP5/6 simulations to examine the structure of atmospheric circulation and the role of anthropogenic drivers leading to these extreme events on annual timescale. We also use large ensembles of specifically designed historical/factual and natural/counterfactual simulations of EC-Earth3 coupled climate model at the standard resolution and weather@home2 climate simulations performed by citizen scientists around the world to assesses to what extent anthropogenic forcing modified the probability and magnitude of this event. Moreover, we involve conditional perspective of the atmospheric circulation in our attribution estimates. The preliminary results points to a pronounced role of the global climate change in modifying likelihood and intensity of these annual extreme events.