3. This caused by human activities and
natural processes.
Answers
Human impact on the environment or anthropogenic impact on the environment includes changes to biophysical environments[1] and to ecosystems, biodiversity, and natural resources[2][3] caused directly or indirectly by humans, including global warming,[1][4] environmental degradation[1] (such as ocean acidification[1][5]), mass extinction and biodiversity loss,[6][7][8][9] ecological crisis, and ecological collapse. Modifying the environment to fit the needs of society is causing severe effects.[10][11] Some human activities that cause damage (either directly or indirectly) to the environment on a global scale include population growth,[12][13] overconsumption, overexploitation, pollution, and deforestation, to name but a few. Some of the problems, including global warming and biodiversity loss pose an existential risk to the human race,[14][15] and some experts attribute this crisis to overall human overpopulation.[16][17]
Answer:
Carbon dioxide (CO2). A minor but very important component of the atmosphere, carbon dioxide is released through natural processes such as respiration and volcano eruptions and through human activities such as deforestation, land use changes, and burning fossil fuels.