"Artificial clouds" driven by solar-powered engines might be deployed at the 2022 World Cup in Qatar to help keep the stadiums from overheating. Each cloud, as a short video hosted over at the BBC explains, "is constructed from an advanced, lightweight, and strong carbon-fiber material."
The interior of the cloud is injected with helium gas to make it float. The cloud hovers like a helicopter and is remotely controlled. In this way, the cloud hovers over the football ground, shielding it from direct sunlight and providing a favorable climatic environment. The cloud is also programmed to continuously change its shielding position according to the prevailing east-to-west path of the sun.So much for roofs, then, if you can simply deploy artificial meteorological events in the form of robotic clouds..."