How would the carbon cycle be disrupted if many plants on Earth died off?

The amount of water in Earth's atmosphere would decrease, trapping water vapor and causing Earth's atmosphere to become warmer.
The amount of carbon dioxide in Earth's atmosphere would increase, trapping water vapor and causing Earth's atmosphere to become warmer.
The amount of oxygen in Earth's atmosphere would increase, releasing water vapor and causing Earth's atmosphere to become cooler.
The amount of nitrogen in Earth's atmosphere would increase, releasing water vapor and causing Earth's temperature to become cooler.

The amount of carbon dioxide in Earth's atmosphere would increase, trapping more heat and causing Earth's atmosphere to become warmer. When plants photosynthesize, they take in carbon dioxide from the atmosphere and release oxygen. Therefore, if many plants die off, there would be fewer organisms actively removing carbon dioxide from the atmosphere. This would lead to an imbalance in the carbon cycle, with more carbon dioxide being released than being absorbed. Consequently, the increased concentration of carbon dioxide would contribute to global warming and climate change.