The statement "sherpas are Everest's workforce - the literal backbone of the climbing industry" is a claim. A claim is an assertion that someone makes, which can be supported by evidence or reasoning. In this case, the author is asserting the significant role and essential contributions of Sherpas in the context of climbing Mount Everest and the overall climbing industry.
To support this claim, the author would need to provide evidence, such as statistics, anecdotes, or other data demonstrating how Sherpas contribute to the climbing experience, ensuring safety, guiding climbers, and facilitating logistics. The phrase "literal backbone" emphasizes their importance, suggesting that the climbing industry would not function as well without them. However, as it stands, the statement functions as a claim because it presents an assertion that requires further support to be substantiated.