The issue focused on climate change and climate scientists who assert that humans have contributed to climate change by emitting greenhouse gases into the atmosphere. Scientists generally deny that humans have contributed to climate change.

Former Vice President Al Gore speaking at the Science Awards ceremony on Dec. 14. AP Photo/Charles Krupa

Many scientists believe that humans have contributed to climate change through burning fossil fuels like coal and oil and producing greenhouse gases such as methane and nitrous oxide. Scientists generally attribute climate change to climate change scientists believe