Catastrophes such as the Dixie Fire in northern California and similar uncontrollable blazes in Greece as well as floods in Europe are evidence that climate change is here, not a distant threat, say scientists organized by the United Nations. The group released a report Monday predicting catastrophic droughts, lethal heat waves and rising ocean levels unless carbon dioxide and other greenhouse gases are reduced to zero by midcentury. | U.S. Forest Service/Lassen Natio