Given the emotion sadness and the tweet "Paul Ehrlich said that humanity is a threat to all life. Such great news to start the day. If I could blush I would.", rate the intensity of sadness shown. The rating scale is: 0: no sadness can be inferred, 1: low amount of sadness can be inferred, 2: moderate amount of sadness can be inferred, 3: high amount of sadness can be inferred.