Evaluate the tweet for the intensity of the emotion sadness. The categories are as follows: 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.
Tweet: We're in contained depression. Only new economic engine is #Sustainability, say Joel @makower + @markmykleby @ #VERGEcon. #NewGrandStrategy
2: moderate amount of sadness can be inferred