<em>Earth's temperature increases because Hout decreases.</em>
Explanation:
The greenhouses gases are known to cover the earth just like a blanket. The greenhouse gases are known to increases day by day due to certain human activities like burning coal or natural gases. As a result, these green house gases get trapped in the Earth. This makes the heat from the Earth to get tapped in the Earth and not get dissipated. As a result, the temperature rises.