Question

which human activity contributes most to the increase in atmospheric co2? recycling waste that is produced burning of fossil fuels for energy using energy efficient appliances

Explanation:

Recycling waste reduces resource use and CO₂ emissions. Using energy - efficient appliances decreases energy consumption and thus CO₂ emissions. Burning fossil fuels (like coal, oil, and gas) releases large amounts of CO₂ that was stored in the Earth for millions of years.

Answer:

burning of fossil fuels for energy