The atmospheric lifetime of CO2 is difficult to determine due to different removal processes. In 2013, CO 2 levels surpassed 400 ppm for the first time in recorded history. They were started by C. David Keeling of the Scripps Institution of Oceanography in March of 1958 at a facility of the National Oceanic and Atmospheric Administration … Its neglect in the calculation of global warming potentials leads many to underestimate the longevity of anthropogenic global warming. They tell us that levels of carbon dioxide (CO 2) in the atmosphere are higher than they have been at any time in the past 400,000 years. During ice ages, CO 2 levels were around 200 parts per million (ppm), and during the warmer interglacial periods, they hovered around 280 ppm (see fluctuations in the graph). The last time the atmospheric carbon dioxide was this high, sea level was 50 to 80 feet higher than it is today and 3.6°–5.4°F warmer than pre-industrial temperatures. In a review by Archer et al. The graphs show monthly mean carbon dioxide measured at Mauna Loa Observatory, Hawaii. Roughly, the total atmospheric carbon is eight hundred gigatons and photosynthesis absorbs seventy gigatons of carbon per year, giving a lifetime of about twelve years. This is the average time that a carbon dioxide molecule spends in the atmosphere before it is absorbed by a land plant. Some unknown process on this planet seems to be persistently adding carbon dioxide to its atmosphere. Common measures of the atmospheric lifetime of CO 2, including the e-folding time scale, disregard the long tail. The carbon dioxide data on Mauna Loa constitute the longest record of direct measurements of CO 2 in the atmosphere. “We are harming the natural world – to our own detriment. “Nature is sending us a clear message,” said UN Secretary-General António Guterres. Atmospheric levels of carbon dioxide—the most dangerous and prevalent greenhouse gas—are at the highest levels ever recorded. Seasons come and go, but the composition of the planet is changing during your own lifetime. Due to the very long lifetime of CO2 in the atmosphere, the impact of a drop in emissions is not expected to lead to a reduction of CO2 concentrations in the atmosphere.