Chemical analysis of natural CO₂ rise over the last 50,000 years shows that today's rate is 10 times faster Phys.orgCarbon dioxide is accumulating in the atmosphere faster than ever The Washington PostThis 50,000-year-old block of ice reveals the true state of CO2 levels now New AtlasRecord-breaking increase in CO2 levels in world’s atmosphere The GuardianCarbon Dioxide Levels at Hawaii's Mauna Loa Observatory Make Record Leap Bloomberg