The researchers began observations of sea level through satellites in 1993. – shortly after the eruption of Mount Pinatubo in the Philippines, which took place two years earlier. On this basis, they estimated that every year the sea level rises by approx. 3 mm. After a careful analysis of the data recognized, however, that the start of the measurements of sea levels more or less at a time when there was a volcanic eruption has led to incorrect conclusions.
Global warming contributes to raising the level of the oceans in different ways: increasing their temperature – and thus the volume, while melting glaciers and snow cover, from which water flows into the oceans. In recent years the rate of warming and melting clearly accelerated. Scientists thought that translate into a corresponding increase in sea levels. Analysis of satellite data, but this is not confirmed.
Scientists predict various natural phenomena, using computer models. They do this based on data collected over decades. So also is the case with the assessment of the state of the seas.
The authors remind that the eruption of the volcano Pinatubo in 1991 . caused a temporary cooling of the globe, which led to falling sea levels. However, in subsequent years the impact of the volcano was not as strong. Unfortunately, estimates of sea level rise is still used old computer models that take into account the still very intense impact of the volcano. As a result, scientists were still convinced that the oceans do not rise as rapidly as it was in reality.
– Large volcanic eruptions can influence the interpretation of the satellite record in estimating changes in sea levels. We need to look carefully at the data, when we consider the effects of climate change – said one of the authors, Steve Nerem from the University of California.
arrangements were made under the guidance of researchers from the National Center for Atmospheric Research in the US.