It can be challenge to make the case for global warming when you can’t even see carbon dioxide and other heat-trapping gas.

Well, this animation NASA’s Goddard Space Flight Center might help ease that burden just a bit. The supercomputer climate simulation shows two different sources of atmospheric carbon dioxide — fires and massive urban centers known as megacities.

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Climate models like this help scientists better understand how carbon dioxide and other gases travel around Earth’s atmosphere and how carbon moves through the air, land and ocean over time. That in turn can help them better project how rising emissions will impact the climate.

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This animation shows a five-day period in June 2006. The model is based on real emissions inventory data and is then set to run so that scientists can observe how the greenhouse gas behaves in the atmosphere once it has been emitted.