Local and global impacts of energy technologies

0:00A phone charging at the wall gives off no smoke. Does that mean its electricity has no impact anywhere?

0:07This electricity comes from technologies that transform energy: a dam and a power plant burning fossil fuels.

0:15Their impacts come at two scales. A local impact changes one place, like this valley.

0:22Building mines, wells, pipelines and power lines clears habitat, the natural home of plants and animals.

0:31A dam floods the land behind it to make a reservoir, a human-made lake.

0:36Burning fuel in vehicles and power plants makes smog and soot, air pollution that can harm people's lungs.

0:44Some power plants return warm cooling water to the river, which can harm fish.

0:50Now zoom out from one valley to the whole planet.

0:57A global impact affects the whole planet, like the carbon dioxide released by burning fossil fuels.

1:04Carbon dioxide mixes through the whole atmosphere, so gas from one valley spreads all around Earth.

1:12The extra gas traps more heat and drives climate change: long-term warming and changing weather everywhere.

1:20The scales do not always match. A large dam is low carbon, giving off little carbon dioxide, but it floods a valley.

1:31Or the reverse: your plug is clean where you are, but power from fossil fuels adds carbon dioxide to the whole atmosphere.

1:40So clean at the plug does not mean no impact: check both the local place and the whole planet.