CO2 Levels and Sea Level Rise

A brief look at where we have been, where we are now, and where we’re going

A picture of Greenland melt streams. Sea Level is rising with accelerated melting -NASA

A picture of Greenland melt streams. Sea Level is rising with accelerated melting – NASA

The last time there was this much CO2 in the atmosphere (>400ppm) was 3 million years ago. Back then, temperatures were 2°C to 3°C (3.6°Fto 5.4°F) higher than pre-industrial temps. Sea levels were 50-80 feet (15-25 meters) higher than they are today.

Sea levels have risen 8 inches since 1880 due to melting land ice and warmer oceans which causes water to expand (90% of global warming goes into the ocean). 8 inches may not sound huge, but sea level rise started accelerating in the ’90’s. NOAA estimates we’ll have an additional 1 to 8 feet* (.3 to 2.5 meters) of sea level rise by 2100. Estimates used to be lower, but experts have been significantly increasing them as they learn more about how ice melts at the poles. All eyes are on Antarctica and Greenland which hold 220 feet of potential sea level rise at bay in their ice.

*1-8 feet is a global average. The East coast of the US is expected to get levels far higher than this average (some models estimate 25% to 100% higher…the experts don’t really know yet).

sea level rise - populations are vulnerable - Miami

Photo of South Beach, Miami. Many coastal communities are vulnerable to rising seas.

Let’s start minimizing our emissions ASAP, shall we?


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