However, scientists have long expected that the story should be even worse than this. Predictions suggest that seas should not only rise, but that the rise should accelerate, meaning that the annual rate of rise should itself increase over time. That’s because the great ice sheets, Greenland and Antarctica, should lose more and more mass, and the heat in the ocean should also increase.
The problem, or even mystery, is that scientists haven’t seen an unambiguous acceleration of sea level rise in a data record that’s considered the best for observing the problem — the one that began with the TOPEX/Poseidon satellite, which launched in late 1992 and carried an instrument, called a radar altimeter, that gives a very precise measurement of sea level around the globe. (It has since been succeeded by other satellites providing similar measurements.) [...]
In a new study in the open-access journal Scientific Reports, however, Fasullo and two colleagues say they have now resolved this problem. It turns out, they say, that sea level rise was artificially masked in the satellite record by the fact that one year before the satellite launched, the Earth experienced a major cooling pulse.
The cause? The 1991 eruption of Mount Pinatubo in the Philippines, which filled the planet’s stratosphere with aerosols that reflected sunlight away from the Earth and actually led to a slight sea level fall in ensuing years as the ocean temporarily cooled.
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