'It' is the carbon dioxide reading at the Mauna Loa Observatory. The reading was in excess of 410 parts per million (ppm), the highest in millions of years. In 1958 it was only 280 ppm.
The problem, as we know, is world-wide. Venice is installing $6 billion worth of sea gates to protect against increased tidal flooding. The Great Barrier Reef is disappearing. Coastal erosion threatens scores of treasured sites in Scotland. Easter Island is in danger.
Here, most of the glaciers that in the 19th century dotted what is now Glacier National Park have already melted, and the rest are expected to be gone within this century. Archaeological sites on the Alaska coast are being lost. The Statue of Liberty, cannot be considered safe: Flooding from Hurricane Sandy destroyed much of the infrastructure on Liberty Island in 2012.