Environment

The U.S. had its hottest year on record last year. That heat, combined with the relatively dry winter that came before, has brought a historic drought.

From forest fires and low crop yields, to infrastructure and recreation, the drought has been costly, with early estimates putting the cost at between $50 billion and $80 billion.

The United States is in the midst of a natural gas boom — about 200,000 gas wells have been drilled in the past decade. The boom has been fueled by the use of hydraulic fracturing — or fracking — which involves pumping a mixture of water and chemicals into the ground to get access to the gas.

Temperatures will continue to rise in America, "with the next few decades projected to see another 2 degrees [Fahrenheit] to 4 degrees [Fahrenheit] of warming in most areas," according to the latest National Climate Assessment, which came out Friday afternoon.