Global Temperatures Could Be Rising Beyond Our Expectations

Recent data indicates that global temperatures are 6% higher than earlier estimates, meaning our planet is experiencing more warming than previously thought.

This trend puts us at risk of surpassing the Paris Agreement’s temperature threshold of keeping global warming below 1.5°C by as early as 2028, rather than the anticipated timeframe of 2030-2035. This is a frequent topic among scientists.

2024 marked the first calendar year where global average temperatures exceeded 1.5°C, following unprecedented warmth that caught climate experts off guard. Although this alone does not breach the Paris Agreement target, it raises concerns over a sustained temperature rise occurring faster than anticipated.

To assess our progress, Gottfried Kirchengast and Moritz Pichler from the University of Graz in Austria utilized the global temperature dataset to revise estimates of global average surface temperature (GMST) from 1850 to 2024. GMST is crucial in measuring global warming, as per the Intergovernmental Panel on Climate Change (IPCC).

The duo also devised a new method for converting GMST, which combines sea surface temperatures and air temperatures, into a single surface air temperature (GSAT).

“Our benchmark records maximize traditional temperature datasets and yield this new enhancement,” Kirchengast notes. This refines the range of uncertainty and demonstrates that global warming is slightly accelerating compared to prior methods, indicating an approach toward the critical 1.5°C mark.

Kirchengast emphasizes that this refined GSAT record is vital for evaluating global efforts toward the Paris Agreement’s objectives. The goal was to establish “a unified reference dataset for global warming in relation to pre-industrial levels,” he elaborates.

Under the Paris Agreement of 2015, nations collectively pledged to limit global warming to well below 2°C above pre-industrial levels while striving to restrict the temperature increase to 1.5°C.

These objectives are typically assessed against 20-year average temperatures, yet researchers disagree on the optimal calculations. Rather than relying solely on historical observations, we recommend using rolling averages derived from a mix of observational data and forecasts due to the increased number of scientists valuing a 10-year delay in evaluating non-compliance with any given target.

Kirchengast and Pichler propose employing novel benchmark GSAT records along with predictive climate models to provide real-time global warming metrics in relation to progress toward Paris targets. Their findings indicate that current warming levels have surpassed 1.39°C compared to pre-industrial benchmarks.

However, Duochan from the University of Southampton in the UK argues that GSAT records are not the best metric for determining the rate of global warming. “The GSAT is not the primary metric utilized in IPCC discussions or most climate target evaluations,” he remarks.

On the other hand, GMST continues to correlate with various changes in the climate system, such as sea level rise and alterations in precipitation, he notes. “For rigorous accountability, GMST remains a highly effective metric,” he argues.

Andrew Jarvis from Lancaster University in the UK emphasizes the urgent need for the scientific community to reach a consensus on a standardized method for measuring progress toward Paris objectives. “The diverse range of estimates is actually complicating policy assessments,” he contends.