Scientists: 2024 Likely Hottest in 125,000 Years

Multiple scientific syntheses and the World Meteorological Organization report that 2023 and 2024 were the warmest years on record, and the 2024 State of the Climate assessment says 2024 was likely the hottest in some 125,000 years. Scientists attribute the unprecedented global and ocean warming primarily to human-caused increases in carbon dioxide and methane from fossil-fuel combustion, with rising energy demand from AI and electrification complicating decarbonization. Reports warn that an accelerating planetary energy imbalance, severe marine heatwaves and weakening ocean carbon sinks are driving dangerous feedbacks that could trigger tipping points and widespread ecological harm. Analyses also highlight cascading risks to human health and ecosystems, including biodiversity loss that may erode beneficial human microbiome diversity and an expanding dengue risk range. The Wood Mackenzie Energy Transition Outlook projects roughly 2.6°C warming by 2100 and says net zero by 2050 is unlikely without major investment and systemic change. Researchers urge urgent policy action — faster renewable deployment, forest protection and improved farming practices — while noting short-term regional variability in weather across regions such as the Pacific Northwest and the Bay Area.