How are the Earth's climate and atmosphere changing? Which human activities are contributing to this? How can we reduce our impact?

Our atmosphere is composed of a number of gases, including nitrogen, oxygen, argon, and carbon dioxide. These gases are needed for our survival and have their individual uses (oxygen for respiration, carbon dioxide for photosynthesis, et cetera). The concentration of these gases has been relatively constant over a very long time in our history. Now, however, the status quo is changing and carbon dioxide concentration is rising. It has been estimated that, since the start...

Our atmosphere is composed of a number of gases, including nitrogen, oxygen, argon, and carbon dioxide. These gases are needed for our survival and have their individual uses (oxygen for respiration, carbon dioxide for photosynthesis, et cetera). The concentration of these gases has been relatively constant over a very long time in our history. Now, however, the status quo is changing and carbon dioxide concentration is rising. It has been estimated that, since the start of industrial age, the concentration of carbon dioxide in our atmosphere has risen by a factor of 1.4 and currently is at the highest levels seen in the last 800,000 years.

The rise of carbon dioxide concentration is a major change in our atmosphere and is causing global warming due to the greenhouse effect. The average temperature of the Earth has increased by 0.8 degrees Celsius since 1880 C.E. This is causing changes in our climate. The most important contributor to this climate change is the combustion of fossil fuels, which power our industries, automobiles, and fulfill our energy demands. Deforestation is another human activity contributing to climate change. 

There are a number of ways we can hopefully reduce the rate of climate change. One of them is to lessen our production of carbon dioxide. This can be done by increasing our use of renewable energy options, such as solar and wind energy. We can also reduce our dependence on energy by living a greener lifestyle by walking and carpooling instead of driving alone. Planting trees is another method to arrest the climate change.

Hope this helps.