Final answer:
The burning of fossil fuels releases carbon dioxide, a greenhouse gas that intensifies the greenhouse effect, leading to climate change and global warming with effects like ice cap melting and rising sea levels.
Step-by-step explanation:
Burning fossil fuels affects Earth's temperature due to the release of carbon dioxide (CO2), which is a potent greenhouse gas. When fossil fuels such as coal, oil, and natural gas are burned, the carbon that was once stored in them re-enters the atmosphere. This phenomenon increases the greenhouse effect, where gases trap heat within Earth's atmosphere, preventing it from escaping to space, and consequently leading to a rise in global temperatures. This process is known to contribute significantly to climate change and global warming, with impacts such as the melting of ice caps and rising sea levels, which threaten ecosystems and human societies alike.