Depending on its energy sources, the way a region produces and consumes electricity can have a profound impact on the environment. This is particularly true for carbon-intensive electricity sources such as coal and oil, whose carbon dioxide emissions contribute to global climate change. Readers curious to learn about the impact of electricity generation and consumption in their area and how it compares to other places should check out electricityMap. This open-source, interactive map compiles electricity data to show the carbon intensity of electricity consumption in different regions based on how that electricity was produced. Visitors can toggle the map to show the real-time wind and solar energy potentials around the world and to account for electricity imports and exports, and they can select individual regions to see more detailed information about each region's electricity sources and carbon emissions. Because electricityMap depends on publicly available data, not all regions are currently covered but users can contribute data to add an area to the map. Launched in 2016, electricityMap is a project of Tomorrow, a startup company based in Denmark and founded by Olivier Corradi, a machine-learning engineer. Through electricityMap and its other projects, Tomorrow aims to make "the climate impact of everything ... accessible to everyone."