10 votes Carbon dioxide levels hit landmark at 415 ppm, highest in human history Posted May 15, 2019 by dubteedub Tags: climate change, co2, carbon emissions, emissions https://www.usatoday.com/story/news/world/2019/05/13/climate-change-co-2-levels-hit-415-parts-per-million-human-first/1186417001/ Link information This data is scraped automatically and may be incorrect. Authors Ryan W. Miller and, Doyle Rice Word count 531 words