Ishii et al. from Japan’s Environment and Marine Department has analyzed time series observations of many oceanic CO2 parameters measured just off the southern coast of Honshu, Japan. Their measurements, spanning a 14-year period from 1994-2008, consisted of partial pressures of CO2, pH levels, aragonite saturation rates, and calcite saturation rates. The results from Ishii’s analysis shows a moderate trend of increasing pCO2 levels, and decreasing pH levels, aragonite saturation rates, and calcite saturation rates over the 14-year period. The trends discovered in the study all show that ocean acidification is continuing to intensify and particularly threatening calcifying species with the declining aragonite and calcite saturation rates. However, the data show a very significant seasonal pattern where pH and carbonate saturation rates peak during the summer months and dip in the winter months. Ishii et al. attributed this to the lower water temperatures as well as upwelling of CO2 rich waters up to the surface during the winter months.
Journal of Geophysical Research 116, 649-659 (2010)
Industrial fossil fuels and decline in the oceans and lands absorption of gas have caused carbon dioxide to rise higher than expected. Carbon dioxide emissions were 35% higher in 2006, than they were in 1990. In the Proceedings of the National Academy of Sciences, this is a much faster incline than anticipated. Since 2000, carbon dioxide levels have been rising by 1.9 ppm (parts per million) annually.
A chunk of the change is due to economic activity, carbon intensive economies, and fading ocean carbon sinks. The sink reduction can be caused by changes in wind circulation, or by rising ocean temperatures that reduce the ability to absorb carbon dioxide. Burning fossil fuels rose 1.3% per year from 1990-1999, and 3.3% in 2000-2006. However, total greenhouse gases are not increasing as much as carbon dioxide alone.
Global climate models did not do a good job predicting climate changes. It is changing much faster than the predictions stated, and the sea level is rising much faster than previously predicted.
Business and the Environment, ISSN 1052-7206, 12/2007, Volume 18, Issue 12, p. 14
Great Barrier Reef Concerns
Skeptical Science doi:2011
The Great Barrier Reef has survived past climate changes with higher carbon dioxide rates and warmer temperatures than today. Even so, there should be concerns about ocean acidification currently effecting the Great Barrier Reef.
In the past, during glacial periods, sea levels were 100 m lower than they are today. The Great Barrier Reef was left exposed, and after the glaciers melted, the reefs were covered with soil.
The changes during the melting of glaciers, occurred over a span of 10-20,000 years. Today, temperatures change by 5-8 degrees Celsius by 100 ppm, over a time span of less than 100 years. The rate of change is significantly 100-200 times faster than in the past. The northern end is more adjusted to warm temperatures, and animals cannot cross 2500 km within 100 years, or 25 km per year, to the southern end.
Humans depend ecologically, and economically due to tourism, on the Great Barrier Reef. Unfortunately, rapid changes are occurring with very little time to adjust.