1) When a star's temperature or size increases, its luminosity increases. In other words it seems more bright.
2) The electromagnetic spectrum is used to determine different types of light waves (infrared, visible light, x-rays etc.) which produced by different kinds of astronomical objects.
Answer:
To reduce the amout you can go all solar powered to power your house. Fossil fuel is used to make heat. But now days most homes in the United States Of America use solar power or get electricity from wind mills.
The area of skin on the human body is 2.0 square meters, as it is the largest organ in the humab body.
I really hope this helped you! c: