evidence: Atmospheric CO2 concentrations rising faster today than the last 50,000 years, as accurately claimed in recent social media posts Atmospheric carbon dioxide (CO2) concentrations and their current rate of increase is unprecedented in the last 50,000 years, based on ice core data. The highest increase in CO2 in that period occurred over the span of 50 years, but the same increase occurred in only the last five years – which is 10 times faster. As human emissions of CO2 increase, global temperatures rise in response through the greenhouse effect. [...] In May 2024, a number of articles and Facebook posts claimed that carbon dioxide (CO2) concentrations are increasing in Earth’s atmosphere faster than they have in the last 50,000 years. So what sparked this claim?