What is a data center? A data center houses rows of computers and equipment for storing, processing, and transmitting data. They typically have few windows and extra security including cameras and sometimes biometric screening. The computers need a lot of electricity to operate and to keep the equipment from overheating. That also requires more electricity and huge amounts of water for elaborate air conditioning. The International Energy Agency says one large data center uses the same amount of electricity as it takes to power 400,000 electric cars. Tech companies are increasingly using their data centers to train and operate artificial intelligence systems. Training an AI model to learn from huge amounts of data requires additional computing power. Conventional data center services run on processors known as CPUs. AI relies on graphics processing units or GPUs. The IEA estimates that asking OpenAI's chat GBT to compose an answer requires nearly 10 times as much electricity as a traditional Google search. Amazon, Microsoft and Google have all announced plans to tap into nuclear energy to help power their US data centers. They've also helped finance new wind and solar farms and other alternative energy sources. In the near term, however, most data centers are still heavily reliant on the surrounding electricity grid, which is largely powered by burning fossil fuels, the primary cause of global warming. This is making it harder for some countries and tech companies to keep their promises to address climate change.