There are many human activities that destroys, destroyed, and will destroy our ecosystem, some of these are:
1. Too much burning of fuels, causing pollution and warmer and hotter earth.
This not just affects our ecosystem, it also affects us. It can destroy the ecosystem, but how? When air pollution, or land pollution occurs, the plant have to struggle for their lives, and also when the earth got warmer, some soil will be damaged or destroyed, (e.g. El Nino) making the plants suffer to death, and even our diligent farmers who planted them.
2. Cutting of trees
Like in no. 1, this not just affects our ecosystem, it also affects us. When trees are cutted, there is a risk of flood. Trees roots absorb water that makes our roads flooded, on which make these trees very very important and essential for human life and also in other organisms. This cutting of trees may also decrease the habitat of some animals (e.g. birds, monkeys, etc.)