It dismisses other potential causes of warming, like solar cycles and volcanoes, often brought up as alternative reasons for warming by those who do not believe in human - caused climate change. (scientificamerican.com)
The turn of events has left many of Quidsi 263 employees stunned and has led to much speculation about alternative reasons for Amazon's decision. (cnbc.com)
Faced with this complexity, scientists posited alternative reasons for the formation, suggesting that it might protect the birds against predators or let a flock put better navigators up front. (scientificamerican.com)