Expert comment: 2023 warmest year on record

The year 2023 has been confirmed as the warmest on record, driven by human-caused climate change and boosted by the natural El Niño.

Last year was about 1.48C warmer than the long-term average before humans started burning large amounts of fossil fuels, the EU's climate service says.

University of Reading climate experts have reacted to the news.

Professor Hannah Cloke, professor of hydrology at the University of Reading, said: “This report is a grim landmark, but it is pointless to despair. We must respond with action. Scientists and the world’s governments have agreed that it is preferable to avoid the worst impacts of climate change in the future by cutting emissions, and the faster the better.

“All governments, including in the UK, should pay heed to their own existing commitments to cut emissions quickly. We do not have the luxury to exploit new oil and gas reserves in places like the North Sea, or to further delay the transition to low-carbon technologies. We have the solutions available now to stop damaging the planet further, and we have the capability to adapt and prepare for the extremes of weather that we are already facing.”

Professor Chris Hilson, Director of the Centre for Climate and Justice at the University of Reading, said: “Copernicus data has confirmed that 2023 was the warmest global year on record and that nearly half of the days were more than 1.5°C warmer than pre-industrial levels. Some of the anti-climate lobby may now be tempted to argue that we have breached the initial Paris Agreement temperature threshold and thus we should abandon efforts to mitigate and simply learn to live in a warmed world. This would be a great mistake. Not only is no such breach technically made out (which requires a longer timeframe and needs to strip out the additional warming effects of El Niño), but such an approach would produce a catastrophically unjust outcome. The current floods in the UK are a powerful illustration of how climate change produces very uneven impacts, exacerbating existing vulnerabilities. And in a warmer world, those working outside will, in many regions, face increasingly dangerous conditions. 

"While these climate inequalities are real and pressing, the reality is that climate change is ultimately also the great leveller. The wealthy may think that they can shield themselves from a warmer world. But climate breakdown can easily lead to wider systemic breakdowns, including in food systems. At that point there is nowhere to hide. We should therefore avoid the temptation to shrug off these temperatures as the new normal. We can adapt to some things. However, the higher that temperatures rise, so adaptation becomes increasingly difficult, costly and inequitable."

Professor Ed Hawkins, climate scientist at the University of Reading, said: “The record warm global temperatures and devastating extreme weather events of 2023 are a warning that such events will continue to get worse until we transition away from fossil fuels and reach net-zero emissions. A warning that we will continue to suffer the consequences of our inactions today for generations. A warning that we will regret not acting faster when the technologies to reduce emissions are so readily available."

Professor Bill Collins, Professor of Climate Processes at the University of Reading, said: “It is a shock that that this year has unarguably smashed the global temperature record. There is no opportunity here to quibble about hundredths of a degree, exceeding the previous record by 0.17 degrees should be an alarm call to everyone. More global warming is expected to cause even wetter winters in the UK and yet more flooding. This warming is due to ever increasing greenhouse gases, which this report confirms have exceeded their own records again this year. While we are probably now too late to prevent temperature rises reaching 1.5 degrees, deep, rapid and sustained reductions in emissions of carbon dioxide and methane are essential to bring down temperatures below the most dangerous levels.”