Question

which definition best describes global warming?
○ a long - term change in the earths climate
○ a long - term increase in the earths average temperature
○ a long - term change in the climate of a region or a city
○ solar heat that is radiated out into space

Explanation:

Global warming is defined as the long - term increase in the Earth's average temperature, mainly due to the greenhouse effect caused by increased levels of carbon dioxide, chlorofluorocarbons, and other pollutants. The first option is too vague as it just mentions a long - term change in Earth's climate (climate change is a broader term). The third option is about a region/city's climate change, not global. The fourth option is about solar heat radiated out, which is not related to global warming. So the correct option is the one about the long - term increase in Earth's average temperature.

Answer:

B. a long - term increase in the Earth's average temperature