Trump’s order comes as new data show last month was the hottest March on record for a year without an El Niño episode. The National Oceanic and Atmospheric Administration says the average global temperature last month rose 1.8 degrees Fahrenheit—or 1 degree Celsius—above normal. The finding came as the Mauna Loa Observatory in Hawaii said atmospheric levels of carbon dioxide reached a record 410 parts per million this month. Climate scientists say the maximum safe level is 350 parts per million.