evidence: By 2100, we could see as little as 8 inches of additional sea level rise, or over 6 feet—based partly on how much we continue to pollute the climate, and partly on how the oceans respond to climate change that's already baked in. [...] An important question is how much climate-warming greenhouse gas we continue to put in the atmosphere. In the rosiest possible future, global average sea level will rise another 20 to 50 centimeters (8 to 20 inches) by the year 2100. Minchew says the low end of that range would require humanity to achieve negative greenhouse gas emissions—in other words, not only stopping new emissions but also removing some excess greenhouse gases already in the atmosphere. The higher end, 50 cm, would occur if we did not meaningfully manage to cut our emissions, but still avoided a spike in sea levels from the collapse of major ice sheets or glaciers.