The World’s Hottest 12 Months in Recorded History


Global temperatures soared over 1.3 degrees Celsius, marking the hottest 12-month period in recorded history due to human-induced climate change. The extreme heat waves affected over a quarter of the world’s population, with a foreseeable impact on international climate negotiations.

Unprecedented Global Heat

Between November 2022 and October this year, the world experienced the hottest 12-month period on record, with the average global temperature over 1.3 degrees Celsius above pre-industrial levels. An analysis of international data conducted by Climate Central scientists revealed that human-induced climate change significantly contributed to the elevated temperatures worldwide.

Impacts on Different Regions

While Australia did not witness the same extreme conditions as other parts of the world, a hot and dry summer is anticipated. The study found that a quarter of the global population faced a five-day heatwave attributed to human-induced climate change. These findings forewarn the impending impacts on various regions, particularly in the lead up to international climate negotiations at the end of the month.

Climate Shift Index Analysis

Climate Central’s scientists employed a methodology called the Climate Shift Index (CSI) to gauge the influence of human-caused climate change on extreme daily temperatures at a local level. This method helped in quantifying the impact of climate change on the likelihood of people experiencing extreme temperatures. The analysis indicated that most people around the world had encountered temperatures substantially affected by climate change.

Regional Vulnerability

The list of countries most affected by climate change primarily comprised small island nations and developing countries, particularly in the Caribbean and Indo-Pacific regions. In Kenya, principal meteorologist Joyce Kimutai noted that increased temperatures were hitting vulnerable populations the hardest. The analysis showed that more than half of the countries in all regions of the world had experienced temperatures higher than their normal monthly averages, impacting over 5.8 billion people.

Accelerating Impacts

Developed nations also experienced accelerating impacts, with unusual heat levels observed in the last six months in countries such as Saudi Arabia, Mexico, and Indonesia. The data indicated that climate change was significantly contributing to these extreme temperature events.

Impact of Heatwaves

According to World Weather Attribution lead scientist Friederike Otto, climate change had the strongest influence on heatwaves, being a game changer in this context. The analysis highlighted that a quarter of the world’s population had faced a five-day heat streak, which was at least two times more likely due to human-induced climate change. Regions like the United States and Indonesia experienced exceptionally severe heat waves, demonstrating the profound impact of climate change on extreme weather events.

Record-breaking Trend

The unprecedented temperatures observed globally aligned with scientists’ predictions for rising greenhouse gas emission levels in the atmosphere. Climate Central’s Dr. Pershing noted that the record-breaking temperatures reflected the long-term warming trend driven by increasing carbon dioxide levels. While attributing the anomalies to the normal weather cycles of La Niña and El Niño was challenging, the 12-month record was consistent with the overall warming trajectory.

Continued Warming Trend

Meteorologist Dr. Kimutai emphasized the constant upward trend in global warming, despite yearly variations in temperatures. She acknowledged that while temperatures might fluctuate, the overall trend indicated a consistent warming of the planet.