A very large wave
Tsunami
When humans put trash or other dirty things into the environment
Pollution
Dangerous weather and environmental changes caused by human activity
Climate Change / Global Warming
When the shifting of Earth's plates causes the ground to shake violently
Earthquake
When humans cut down too many trees
Deforestation
A large rock from space that can cause incredible damage
Asteroid
A place where hot magma can shoot out of the Earth in a violent eruption of ash, rock, and fire
Volcano
When the black liquid that powers our cars leaks into the natural environment
Oil spill
Massive volcanoes that have the potential to destroy most, or all, life on the planet if they explode. There are 4 active ones on Earth, but they only explode every million years or so
Supervolcanoes
An extremely powerful windstorm that rotates in a circular motion
Tornado / Cyclone
When humans edit genetic code. This can lead to great scientific advances, but also to biological weapons or unforseen consequences...
Genetic Engineering
When humans create weapons from viruses or other living matter
Biological Weapons (Bioweapons)
The biggest storm systems on the planet
Hurricane / Typhoon / Cyclone
BONUS: What is the difference between the 3?
When something really bad happens as a result of human industry (explosion, mining cave-in, large pollution events, etc.)
Industrial disaster
When a large star explodes, causing the largest explosion in the universe which can wipe out entire solar systems
Supernova