This article discusses the new GHG emissions threshold.
The Earth’s atmosphere is more saturated with greenhouse gases now than at any other time in human history. For the first time on record, the average amount of carbon dioxide — the main long-lived gas responsible for global warming — in the air passed 410 parts per million (ppm) for an entire month.
Data collected at the Mauna Loa Observatory in Hawaii had already shown carbon dioxide readings that temporarily exceeded that threshold for a time in 2017 but not for a whole month. The new data collected for the month of April and released on May 2, underscore how quickly carbon dioxide levels continue to rise despite global attempts to reduce emissions.