1. Complete the sentence. ____________ affects the way heat is distributed on Earth's surface.
Earth's tilt on its axis
Earth's distance from the sun
The speed of Earth's rotation
The speed of Earth's revolution

2. Two greenhouse gases, carbon monoxide and carbon dioxide, have increased Earth's temperatures due to the burning of fossil fuels. This phenomenon is known as
global warming
climate change
greenhouse effect
positive feedback

It doesn't mean that temperatures everywhere are hotter. The angle at which sunlight hits Earth is one of the most important factors impacting the average temperatures in a region. Higher angle (more direct) sunlight warms Earth more effectively. Earth's axis is tilted by ~23°.

Earth's tilted axis causes the seasons. Throughout the year, different parts of Earth receive the Sun's most direct rays. So, when the North Pole tilts toward the Sun, it's summer in the Northern Hemisphere. And when the South Pole tilts toward the Sun, it's winter in the Northern Hemisphere.