We just returned from a National Geographic guided tour of Alaska aboard the ship Sea Bird. The food served was all McDougall style: low-fat, vegan, and starch-based (with some very rich desserts—an option). The cruise line, Lindblad Expeditions, referred to us as "the vegan, no oil charter." Every aspect of this McDougall Adventure trip was excellent.
This was my third trip to Alaska (1993, 2001, and 2016). Massive melting of the glaciers was obvious and a topic frequently discussed among our group. However, our National Geographic guides, including one national park ranger, seldom mentioned the connection between global warming caused by human activities and the threat to these northern lands. Dwelling on this topic may have detracted from the travelers' enjoyment of their trip. I suppose no one wants to hear about the changes we all need to make in order to keep our planet healthy.
I would have thought that our group of 62, practicing various levels of veganism, might have inspired some acknowledgement from our guides about the impact of livestock production on the destruction of the habitats we were visiting. Over half of all greenhouse gasses produced are due to people eating animals. I, unfortunately, heard no mention of this connection during our cruise despite the National Geographic Magazine articles previously addressing this subject, such as, "Vegetarianism: More Than 'Meats' the Eye." Many of the guides ate their meals with us, and some of the ship's crew showed interest, but this was about as far as it got.