For many, President Joe Biden’s first days in office have spelled a positive shift away from Trump-era policies – arguably no more so than for environmentalists. In his first week at the helm, the US has rejoined the Paris Agreement, set in motion plans to ban new oil and gas leases on federal lands, and rescinded the permit for the controversial Keystone XL pipeline. It was inevitable that there would be costs from these policies – both social and financial – and Biden’s true test will come in how to keep these to a minimum. A rapid acceleration of hydrogen infrastructure provides one of the only answers. Keystone XL is the posterchild of this problem, encompassing predicaments in transboundary trade,…