Recent global temperature surge amplified by record-low planetary albedo

TL;DR

The 2023 global temperature surge is largely due to record-low planetary albedo caused by decreased low-cloud cover, highlighting the importance of cloud feedbacks in climate change.

Contribution

This study identifies record-low planetary albedo as the main driver of recent temperature increases, emphasizing the role of cloud cover changes in climate variability.

Findings

2023 temperature exceeded previous records by 0.17K.

Record-low planetary albedo explains the unexplained temperature rise.

Reduced low-cloud cover in key regions is a major factor.

Abstract

In 2023, the global mean temperature soared to 1.48K above the pre-industrial level, surpassing the previous record by 0.17K. Previous best-guess estimates of known drivers including anthropogenic warming and the El Nino onset fall short by about 0.2K in explaining the temperature rise. Utilizing satellite and reanalysis data, we identify a record-low planetary albedo as the primary factor bridging this gap. The decline is caused largely by a reduced low-cloud cover in the northern mid-latitudes and tropics, in continuation of a multi-annual trend. Understanding how much of the low-cloud trend is due to internal variability, reduced aerosol concentrations, or a possibly emerging low-cloud feedback will be crucial for assessing the current and expected future warming.