Amazon's been making waves with its demonstration of Prime Air Delivery service. It's difficult to tell yet whether this will be an environmental win until we know more about the specs.
This Quora suggests that the positives might not be quite as dramatic as hoped.
Part of Amazon's planned Prime Air Delivery service, the new drone is larger than the previous version and has a more advanced design, including the ability to apparently operate with an autoloading system that sets the payload inside an internal carrier bay. Unlike the previous drone, which was a quadcopter, this one has a hybrid design that combines vertical lift and horizontal flight capabilities using lift fans and a pusher prop. Amazon hasn't given out too many details as to specs, but the drone is capable of flying at an altitude of about 400 ft (122 m) at about 55 mph (88 km/h) for a range of 15 mi (24 km). It has sense-and-avoid situational awareness technology, so it can identify and avoid obstacles in the air and while taking off and landing.