There is a new paper out in the Journal of Climate which some have hailed as proof that the global mean sea level is not influenced by human activity. However, this is exactly the opposite of what the study authors explain are the real results.
The following guest post is a briefing note by the Climate Science Rapid Response Team:
There is a new paper out in the Journal of Climate which some have hailed as proof that the global mean sea level is not influenced by human activity. However, this is exactly the opposite of what the study authors explain are the real results.
The study finds sea level rise is still continuing at a steady rate. Study author Dr. John Church has stated via email correspondence, “I would argue that there is an unhealthy focus on one single statistic — an acceleration number — and insufficient focus on the temporal history of sea level change.”
Dr. Church further explained that the reason for a relatively steady rate of rise is partially due to the large rate of CO2-induced warming throughout the century. Melting glaciers contributed extensively to sea level rise in the first half of the century, but in more recent years there is less ice left to melt. This contributes to a steady rather than accelerating sea level rise.
The study also found that thermal expansion of the seas should be reflected more strongly in climate models.
Over all, Dr. Church stated that the results “increase our confidence in models of sea level change and thus increase our confidence in the projections for the 21st century.”
With a complete reading of the paper, it becomes apparent that acceleration is only one part of the larger picture. The planet is rapidly warming and the seas are rising. These researchers are refining our understanding of which factors are driving that rise, and in what proportions.