Story highlights Global sea level is on the rise at an increasing rate, according to a new study

By the end of the century, it could rise another 2 feet

(CNN) Sea level rise is happening now, and the rate at which it is rising is increasing every year, according to a study released Monday in the Proceedings of the National Academy of Sciences.

Researchers, led by University of Colorado-Boulder professor of aerospace engineering sciences Steve Nerem, used satellite data dating to 1993 to observe the levels of the world's oceans.

Changes in sea level observed between 1992 and 2014. Orange/red colors represent higher sea levels, while blue colors show where sea levels are lower.

Using satellite data rather than tide-gauge data that is normally used to measure sea levels allows for more precise estimates of global sea level, since it provides measurements of the open ocean.

The team observed a total rise in the ocean of 7 centimeters (2.8 inches) in 25 years of data, which aligns with the generally accepted current rate of sea level rise of about 3 millimeters (0.1 inches) per year.

But that rate is not constant.

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