News release

From: University of Auckland

NZ climate scientist helps show effects of past decade’s emissions

University of Auckland scientist Dr Emily Gordon contributed to research showing that a recent European heat wave was measurably worsened by emissions since the Paris Agreement on climate in 2015.

The research, led out of Stanford University in the US and published in Geophysical Research Letters, advances climate science by using AI to separate out the effects of subsets of overall greenhouse gas emissions, Gordon says.

“Even emissions since the Paris agreement in 2015 have tangibly increased the magnitude of heat events,” says Gordon, who is a lecturer in the Department of Physics.
Showing the effects of portions of overall greenhouse gas emissions may be relevant to climate litigation seeking to sheet home responsibility to companies or countries.

“Getting down to the level of linking subsets of human-caused emissions to extreme climate events is an active area of research, and we have shown a promising approach to this challenge,” says Gordon.

The research indicates the odds are more than 99 in 100 that emissions during the past decade intensified Europe’s deadly June 2025 heat wave. The researchers estimated the emissions increased average daily temperatures in some regions by roughly a third of a degree Celsius.

That result is not unique to the 2025 heat wave, but also true for Europe’s hottest week in every individual year since at least 2021.

The climate scientist drew on her expertise in training AI on data produced by climate models for understanding and predicting climate change. The study was led by Jared Trok of Stanford University.

The researchers trained a type of generative AI known as a diffusion model using simulated weather data from 10 global climate models.

By analyzing each climate model’s simulated data for the years 1850 to 2100, the researchers’ diffusion model learned how surface temperatures over Europe vary with different emission levels and weather conditions, such as atmospheric pressure and soil moisture levels.

Almost one-fifth of all carbon dioxide emissions from burning fossil fuels have been emitted in the decade since the Paris Agreement was adopted.

Under the Paris Agreement, nearly 200 countries pledged to limit global warming to well below 2 degrees Celsius above pre-industrial levels, while pursuing efforts to limit warming to 1.5 degrees Celsius.

Global warming is already approaching the 1.5 degree Celsius threshold.