Consider the way that plants affect your life. You might wear cotton, eat apples, or admire a daffodil. But plants are also a part of the big picture of Earth’s climate and habitability.
Well, for starters, Earth would be much quieter. Almost all living creatures on our planet depend on plants for food and oxygen, either directly or indirectly. So if all the plants disappeared, eventually so would almost all the other life.
Also, Earth would be hotter. Plants take carbon dioxide out of the atmosphere. If it weren’t for plants, there’d be an increase in the levels of this greenhouse gas — and Earth’s temperature would climb.
Then, too, plants play a role in Earth’s water cycle. They absorb rain and snowfall — and eventually release much of this moisture back into the atmosphere. Without plants, the patterns of precipitation would likely be altered. What’s more, since plants cover much of Earth’s land surface, they decrease the amount of light that our planet reflects back into space. Without plants, Earth would reflect more light — and this would change climate patterns, too.
Finally, plants anchor Earth’s soil. If the plants were gone, soil would be washed from Earth’s surface on a grand scale. So without plants, Earth would be hot — barren — and maybe muddy.