Global CO2 levels reach new heights

摘要

Atmospheric carbon dioxide levels reached another all-time high last month, scientists said today, despite a global slowdown in greenhouse gas emissions during the COVID-19 pandemic. Levels at the Mauna Loa Atmospheric Baseline Observatory averaged 419 parts per million in May, according to scientists from NOAA and the Scripps Institution of Oceanography. It's the highest monthly mean in the observatory's 63-year history. "The ultimate control knob on atmospheric CO2 is fossil-fuel emissions," Ralph Keeling, who runs the Scripps CO2 program at Mauna Loa, said in a statement. "But we still have a long way to go to halt the rise, as each year more CO2 piles up in the atmosphere." He said, "We ultimately need cuts that are much larger and sustained longer than the COVID-related shutdowns of 2020."