In The Bad Future, most places on Earth will be hotter, although there will still be some cold days. School and sports will be canceled during intense heat waves.
High temperatures could even be fatal for vulnerable populations like older people and those who work outside.
Changes in the weather will make it harder for us to grow food. In certain places, water supplies will dry up.
Many people will leave their homes in search of better places to live, and the poor will suffer more than the rich. This is already happening today.
Extreme heat and drought will make wildfires even more dangerous. More of us will be exposed to unhealthy smoke.
Many plants and animals will face extinction from habitat loss and other human threats.
As glaciers and ice sheets continue to melt, rising seas will flood many coastal communities, displacing hundreds of millions of people worldwide by the end of the century.
The ocean will get more acidic as seawater absorbs carbon dioxide from the air.
The water will keep getting hotter, too, which will help some marine animals but hurt others — including many that humans depend on for food.
Coral reefs will likely disappear.