U.S. Steel mines iron ore in Minnesota and sends it across Lake Superior on freighters a thousand feet long. At Sault Ste.

Our devastation of nature is so extreme that reversing even a small part of it requires painstaking, quixotic efforts.

Indigenous rangers are "the eyes and ears for north Australia", keeping wildlife safe from ghost nets and coastlines free from rubbish. Technology is giving them new ways to watch the coasts.