Sea level rising 60% ahead of forecasts
A new study published in the peer-reviewed journal Environmental Research Letters confirms that sea level has been rising 60% faster than the projections. Led by Stefan Rahmstorm, a world-renown oceanographer from the Potsdam Institute – Germany, the paper “Comparing Climate Projections to Observations up to 2011” is the most recent and thorough analysis of sea level change compared to the climate forecasts. As explained climate change is a complex phenomenon with many variables and potential distorted measurements.
Sea level is widely accepted to be the best indicator of the long term temperature of the planet, since it reflects the status of the two great ice sheets and glaciers. Their size can be tracked rather closely with geological evidence going back thousands, hundreds of thousands and even millions of years. A warmer planet means shrinking ice sheets and glaciers, and rising sea level.
The graph at the right from the paper shows the actual sea level measurements in the top gold squiggly line, with the normalized trend line shown in red. The blue and green lines below were the projections. As can be seen the actual is significantly above all the projections.
This is further confirmation that most climate change projections are conservative.
It should be noted that sea level is a lagging indicator to changes in global average temperature. It can take decades or centuries to see the full effect of a new average global temperature reflected in sea level due to the slow process of melting or building the great ice sheets in the polar regions.