Let's explain this in a way that even non-believers can understand. Thermals can get stronger then 10 m/s+ which is equal to about 22mph. Say he flared his suit out to 15mph (easily doable coming out of a slight dive on the bigger suits.) Do the math and you can see how climbs (with the aid of big thermals) are entirely possible, as the video demonstrates. I like fuzzy bunnys!!!