Subject	greenhouse gas
Predicate	has_property
Object	concern
Modality	Modality Occurrences TBC[global concern] 3
Polarity	POSITIVE
Plausibility	0.8252
Neighborhood Sigma	0.8252
Local Sigma	0.9855
Example Sentences	Sentence Occurrences Source greenhouse gases are a concern 2 Google Autocomplete greenhouse gases are a global concern 3 Google Autocomplete greenhouse gas is a concern 2 Answers.com Questions