3 human activities affecting biosphere are burning of fossil fuels, animal husbandry and agriculture. Their effects are explained below.
Step-by-step explanation:
Burning of fossil fuels are heavily used to produce energy for cars, electricity and different uses in industries. But it has a huge impact on environment. Its burning produce a lot of harmful products in environment. Also it produce a lot of carbon dioxide which is a greenhouse gas.
The animal husbandry is of very important cost to environment. It gives the nature different components like cow dung, milk, flesh etc which can be used as food, used to produce biogas and different other elements. But it produce a lot of carbon dioxide and methane which are greenhouse gases.
Agriculture gives the human population food to consume and different other stuff to use in daily lives. But it needs to cut down forests which reduce the oxygen production and can reduce soil fertility.