The greenhouse effect is a process where gases in Earth's atmosphere trap the Sun's heat. This process makes Earth much warmer than it would be without an atmosphere. When we burn fossil fuels, the volume of carbon dioxide increases, which strengthens the effect and leads to global warming. This trend is dangerous for the ecology.

I feel deeply saddened by the photo of the starved polar bear. It is a tragic example of how human activities affect innocent animals in the Arctic. The author mentions the scientists' warning to emphasize that climate change is not just a theory, but a real threat backed by data.

We should take responsibility by changing our lifestyle. For example, we can save energy at home and use public transport more often. As the text suggests, global attention is required to save our planet.