What is the sun powered by?

How do hydrogen nuclei produce helium nuclei and large amounts of energy?

How much energy is there per square meter of the sun's surface in watts?

How much energy is there over the sun's whole surface in watts?

How much of the total energy from the sun is used by the human activities?

What is the solar energy that enters the Earth's atmosphere called?

What is an electromagnetic spectrum?

Which type of wavelength ( shorter or longer ) do X-ray's and ultraviolet lights have?

Which type of wavelength ( shorter or longer ) does infrared radiation have?

What is the ozone layer?

What would happen if the ozone layer did not absorb ultraviolet radiation?

What are some examples of high energy forms of electromagnetic radiation that could damage cells in living organisms?

How can this be prevented from happening?

What affect does this have?

What are greenhouse gases?

What are some examples of greenhouse gases?

What do greenhouse gases do?

What does infrared radiation do?

How is balance maintained in Earth in order for all life to exist?

What would happen if less energy was lost than gained?

What would happen if more energy was lost than gained?

What is the greenhouse effect?

What is the enhanced greenhouse effect?

What is the brown "smog" sometimes seen over cities?

How can volcanoes influence climate?

What would happen if there were no ocean currents?