Concluding Remarks

This blog is finally coming to an end :-(! In the past three months, I truly learnt a lot and thoroughly enjoyed maintaining this blog, and I hope you enjoy reading it too!

Through looking into the ocean’s acid test challenge from the past through to the present and the future, it is interesting to see how the ocean and marine organisms especially corals and calcifiers respond to the ever-changing environment, especially in the anthropogenic era. The power of paleooceanography has let us explore the ocean’s historical carbonate chemistry, such as the catastrophic Paleocene-Eocene Thermal Maximum (PETM) and predict its ability to buffer the increased acidity caused by rising atmospheric CO2. 

Here are my main findings about the ocean’s acid test:

            1. Ocean acidification is about rate of change

The negative impacts and severity of ocean acidification is not necessarily about the levels of pH but the rate of pH decline. The most worrying fact about this ocean acidification phenomenon is the rate of pH decline in less than 300 years during the Anthropogenic Era, much less than any geological period in the past (normally it takes at least 100,000 years for oceanic pH to recover). 

2. Uncertainty
Uncertainty exists in every aspect of this ocean acidification analysis, from paleo-proxy records, response of marine ecosystems especially marine calcifers, to modelling and ocean iron fertilisation technology. Unfortunately, uncertainty always exists in any scientific analysis and it certainly hinders the accuracy and reliability of future projections. Proxy records of much higher spatial and temporal resolutions are probably needed to produce more accurate projections in the future.

3. Ocean acidification is a very localised problem
As we can see from the PETM event, IPCC Scenario model projections and my recent posts about ocean acidification ‘hotspots’, oceanic pH varies considerably in both global and regional scale. For instance, oceanic pH is generally lower across low latitudes and in coastal regions. This spatial variability is likely to be intensified in the future. 

4. Ocean acidification is subject to very contentious debate

Ocean acidification is not necessarily a detrimental phenomenon according to the ‘norm’. Ocean acidification skeptics have found numerous scientific evidences proofing that our oceans are extreme well buffers and indicating positive effects of ocean acidification to some marine organisms. 

Having researched and investigated around the subject, it has certainly challenged my previous perception about the ocean’s acid test. I remember back in secondary school days, my chemistry teacher has explained to us the negative effects of too much carbonic acid in the oceans. A lot of the media reports tend to convince us about how ‘alarming’ this phenomenon would be. However, through looking into the different scientific evidences from various proxy records and the debates around the subject by many oceanographers, I now understand more about the mechanisms behind the oceanic buffer system and how the ocean has responded to past global environmental changes e.g. the vast amount of carbon input into the deep ocean during PETM. More importantly, I found it very interesting to see the debates and arguments from different scientists (‘pessimistists’ Vs ‘optimistists’) around the same subject matter with new data and scientific evidences. It is truly a constantly changing and evolving subject. Therefore, I believe that paleoceanography is indeed a very powerful tool to increase our understanding about our oceans and it has a tremendous potential to help us in future decision-making on ocean acidification mitigation strategies. 

Last but not the least, back to this blog’s ultimate question: Will we pass the ocean’s acid test? There is indeed no simple answer to this question. If you take the pessimistic point of view, we might not be able to pass based on the already decreasing number of corals and marine calcifiers in the ocean and the failures of international agreement in reducing global CO2 emissions. Or, the optimistic skeptics are right; the oceans are extremely well buffers! Whatever you choose to believe, there are always uncertainties embedded in this subject, in both scientific and political perspectives. More research in the future is probably needed to draw us closer to a definite answer.   

Thank you for reading my blog once again and I wish you all have a great year ahead!