After years of skepticism, Americans are more likely to express concern or worry about global warming, though some still say it's exaggerated, a poll indicates. In a poll released by Gallup, 58 percent of Americans say they worry either a great deal or fair amount, about global warming. This is an increase from 51 percent in 2011 but still below the 62 percent to 72 percent levels seen in earlier years, a Gallup release reported Monday. When asked if they have worries about global warming, 33 percent of respondents said they worry "a great deal," 25 percent worry "a fair amount," 20 percent "only a little" and 23 percent "not at all." Over the last 20 years public concern over global warming has fluctuated between about 50 percent to 72 percent, with an average percentage in that time for "worrying a great deal/fair amount" of just slightly less than 60 percent, Gallup said. Americans are less likely than in the recent past to consider news about global warming exaggerated, with 41 percent in the current poll saying so, down from 48 percent in 2010, which was an all-time high. The poll was conducted by telephone between March 7-10, with a random sample of 1,022 adults and a reported margin of error of plus or minus 4 percentage points.