How much of the above ground fresh water is actually usable by humans?

Who is the biggest user of fresh water? 

Institutions used to confine people who are awaiting trial are called:

What chemical(s) are usually the cause of eutropication?

Climate change models predict rainier rainy seasons and dryer dry seasons. How can this be?  

Luckily, after seeing the data, the world came together during the Montreal Protocols to agree on limiting CFCs and begin healing the ozone layer. (I know it is hard to believe considering the state of politics today, but this really happened!) If the agreement had failed, there would be less ozone in the atmosphere today and we would be at a higher risk of cancer. What type of cancer causing radiation does ozone help protect us from? 

Which of the following is true regarding early corn ethanol (biofuel) projects?

Which of these would not be a pillar of food security? 

Albedo refers to 

Using what you know about income and environmental quality – A person’s risk for developing cancer from exposure to polluted air ____ as income ______.