A growing number of Americans are concerned — alarmed even — about climate change, a recent survey found. This is good news and bad news. It is bad news because, although the survey did not ask people why they were concerned or alarmed, it is likely that more Americans are becoming worried about climate change as its consequences become more obvious and severe. The good news, if it can be considered that, is that as more Americans are concerned, it is more likely that needed policy changes and regulations will be put in place to slow greenhouse gas emissions. Of course, such changes need to come soon before climate changes are so severe that they cannot be slowed or mitigated. Since 2013, the Yale Program on Climate Communications and the George Mason University Center for Climate Change Communication have asked Americans about the attitudes and beliefs about climate change. In the latest survey, done in December, 29 percent of those asked said they were “alarmed” about climate change.