(Bloomberg) -- Amazon’s carbon emissions rose for the first time in three years in 2024, driven by data center construction and fuel consumption by its delivery providers. The company’s emissions last year were up by a third since Amazon pledged in 2019 to eliminate them by 2040. Environmental watchdogs have raised the alarm as the AI data center boom helped supercharge electricity demand, and, in some areas, breathed new life into natural gas and coal-fired power. Those energy sources had fallen out of favor among tech companies in recent years as they pledged to find cleaner sources and zero out their impact on carbon emissions. Amazon and fellow data-center giants Alphabet, Meta Platforms, and Microsoft have also signed deals to scoop up carbon-free nuclear power in the coming years.