As far as ground transportation in Antarctica...not to worry....your feet wll not have any emissions. Seriously, when you make landings, you will travel from the ship to the land in a Zodiac, and then it will be walking only.
I hope you have had a chance to view the web site for National Geographic expeditions and also watch some of the videos. Our most incredible moment (and there were many) was being in a Zodiac with a National Geo photographer and a whale researcher, right next to two humpback whale......so very close to one that I seriously could have reached over about two feet to touch him (or her). The whale researcher calmly explained what the whale were doing (logging) and then calmly told us to cover the lens on our cameras right after they inhaled so as to avoid the oil from krill getting our our lens when they exhaled. It was, perhaps, one of the most magical travel moments ever.
If you go,I recommend mid-January, because the penguin eggs will have begun to hatch, but the young penguins will not have begun to lose their baby feathers (sort of molting). We saw chin-strap penguins, adelie. and gento, both humpback and orcas, along with different seals and countless birds.
One poster implied Antarctica is a chunk of ice, but it is oh so lovely with various ice formations, icebergs, and colors (white, blue, etc.). Kayaking among icebergs with cute penguin swimming all around is surreal. One night I was so enthralled looking out my cabin window, three hours went by before I knew it. It never really is dark there, so you will pull a heavy duty block-out shade before pulling curtains to go to sleep.
Lindblad operates safe ships. While they are not the least expensive provider, it is my opinion they are one of the safest. While doing water activities, there was never a naturalist very far from us (translation: if someone went overboard from a Zodiac...which would have been highly unlikely), lots of help would have been there pronto. There was also the opportunity to swim in Antarctica, and my husband did the Artic Plunge :)
Each evening during the social hour before dinner, a naturalist will present, and you will also have a short presentation by the dive team that will show you what they saw that day underwater. Fascinating.
I hope you make the trip!
Dr. Ken Taylor was on our expedition, speaking and sharing results from the multi-decades of leading the ice core drilling research team. He was both fascinating and fun. That trip was the first time he had been in the peninsula, and he was over the moon re: how beautiful it is. The landscape is vast and beautiful. Port Lockery (Google it) is run by the British Trust for Antarctica, and the staff there were charming...you can also mail postcards, but they are postmarked and they wait until the end of the season, when the staff returns home to process the mail thru the British Postal Service.