70% of Americans age 18 to 34 worry about global warming, compared with 62% of Americans age 35 to 54 and 56% who are age 55 and older. The biggest generational gap is visible in the belief that global warming will pose a serious threat in one’s own lifetime – 51% of Americans age 18 to 24 versus 29% age 55 or older, reflecting the different timeframes involved for each age group. The second largest generational gap is around the belief that global warming is caused by human activities – 75% of Americans age 18 to 24 believe that, versus 55% age 55 or older. Young adults are also significantly more likely to think news reports on global warming underestimate the problem – 48% of Americans age 18 to 24 think that, versus 31% age 55 and older.