A macronutrient is a nutrient that is needed in relatively large amounts by organisms.

According to the Law of Matter, the amount of matter put into a system is always more than the amount of matter that comes out.

According to the Law of Matter, the amount of matter put into a system is always more than the amount of matter that comes out.

The richest 20% of the world’s human population consumes approximately what percent of the Earth’s resources?

What is the single largest source of carbon dioxide being added to the atmosphere every year?

What compound is now used as the primary replacement for CFCs?

Livestock, the production of fossil fuels, and the decomposition of wastes in landfills are common sources of what greenhouse gas?

If everyone on Earth lived like Americans do, hypothetically, we would need 5 Earths to support everyone.

Estimates from different sources vary, but it is generally thought that, globally, about how many people die from starvation and/or complications related to malnutrition every year?

With respect to vehicles, what does the abbreviation “CAFE” stand for?