This The Guardian article discusses the latest data which shows steep rises in CO2 for seventh year. Readings from Hawaii observatory bring threshold of 450ppm closer sooner than had been anticipated.
The concentration of carbon dioxide in the atmosphere has increased by the second highest annual rise in the past six decades, according to new data.
Atmospheric concentrations of the greenhouse gas were 414.8 parts per million in May, which was 3.5ppm higher than the same time last year, according to readings from the Mauna Loa observatory in Hawaii, where carbon dioxide has been monitored continuously since 1958.
Scientists have warned for more than a decade that concentrations of more than 450ppm risk triggering extreme weather events and temperature rises as high as 2C, beyond which the effects of global heating are likely to become catastrophic and irreversible.