350ppm is the concentration of CO₂ in the atmosphere where climate change is no longer out of control. The last time our atmosphere was below 350ppm was in the 1980s. It takes decades to feel the effects of extra CO₂ and the planet has warmed just over 2ºF because of this. We're currently over 420ppm, locking in another +2ºF of warming and thus triggering the first major climate tipping points. Carbon dioxide removal is a time traveling pursuit, and forests, soils, rocks, and oceans are our carbon flux capacitors. "Now, we need your help to get back to the year 1985!"
