Parts per million (ppm) is how the concentration of carbon dioxide in the atmosphere is quantified. While this concentration was at 280 ppm CO2 before the industrial era, it has now exceeded 410 ppm CO2. According to renowned climatologist James Hansen, going above 350 ppm CO2 for an extended period of time makes the risk of run-away climate change Run-Away Climate ChangeRun-away climate change is already possible under current levels of global warming. However, beyond certain tipping points, namely the 1.5-2°C…Read on اقرأ المزيد towards a hothouse Earth more likely. This would mean a global temperature rise of 8 °C, sea level rise Sea Level RiseThe two main reasons for sea level rise are thermal expansion of the ocean (the increase in water volume due…Read on اقرأ المزيد of up to 60m, and complete melting of polar ice.