Given the emotion anger 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.", classify the intensity of the emotion displayed in the tweet. The classification options are: 0: no anger can be inferred, 1: low amount of anger can be inferred, 2: moderate amount of anger can be inferred, 3: high amount of anger can be inferred.