. Long before Covid-19 brought global travel to a screeching halt, the problems associated with large numbers of people moving around the planet were becoming obvious. Published last month, Sustainable Travel: The Essential Guide to Positive-Impact Adventures (White Lion Publishing), by Holly Tuppen, is a guide written for travellers wishing to minimise the harm they do as they negotiate the world’s ethical and climate-related challenges. Below are a few of the concerns that are addressed within its pages. 1. Which carbon claims can I trust? The rising concern about the climate crisis has created a wave of claims, from carbon-neutral around-the-world trips to carbon-positive hotels. One minute Hawaii is announcing plans to become a carbon-neutral state, and the next Swedish burger joint Max Burger serves up the world’s first climate-positive burger.