The Ocean Engine: The Finale

It is now time to wrap up and conclude this blog. As stated, the aim of this blog was to explore past changes in ocean circulation; past, present and future. At the beginning of this blog, we sought to define the ocean’s role in the climate system. In particular, I stressed through the concept of the conveyor belt that whilst analogies are good for framing our imagination of ocean circulation, it is important to reconcile that the ocean is a complex mechanical engine in reality. Furthermore, this blog also reviewed techniques in palaeooceanography, to understand how past changes in ocean circulations are reconstructed. Upon reflection, given more time, I feel I could have perhaps added a few more detailed post attached to this topic as it is of crucial importance to understand past changes in ocean circulation.

This blog then explored paleaoclimatological evidence for past changes in ocean circulation. In particular, several episodic were analysed in relation to abrupt climate change; The Younger Dryas, 8.2 ka event and the Late Cretaceous. In this respect, I did narrow my research stand of the “ocean circulation” with respect to the North Atlantic circulation. However, this strand of blog posts could be nicely conceptualised by the posts I did on millennial-scale climate change. I found this strand of research particularly fascinating, given the complexity of feedback processes revealed from ice core studies such as the bipolar seesaw mechanism.

In this respect though, I feel I potentially could have explored two more strands of research in The Ocean Engine; notably the Southern Ocean and the El-Nino southern oscillation, both key are important components of the ocean system in relation to the past and present components. However, I feel that my definition of The Ocean Engine evolved over the course of this blog to run along the following theme; despite popular views advocated in films or by climate skeptics, ocean circulation is a complex science in reality. Thus through focusing on the North Atlantic thermohaline circulation, this blog sought to disentangle the myths attached to this component of the climate system by adopting a palaeo-approach and trying to understanding potential future impacts associated with anthropogenic climate change.

One of the key take-home messages from this blog is that by adopting a palaeo perspective, this can provide a critical position to interrogate questions surrounding climate change. The study of paleoclimatology differs somewhat in ideology to that of modelling, as emphasised in various posts. This divergence is a crucial point to convey a very key message; that anthropogenic climate change puts our understanding of the earth’s climate system to the limit, and we are currently at a stage to make fairly accurate predictions at the impacts but a significant distance away from the goal of quantification. I exemplified this point nicely in the last post, through the concept of noise, which I feel is useful analogy to help explain why uncertainty exists in climate change science; a crucial ingredient to any debate on climate change.

It has been an absolute pleasure writing this blog, and it has enriched my understanding of ocean circulation in relation to debates on climate change. To conclude, whilst we only are beginning to understand the components of The Ocean Engine, we do not understand its interior mechanics and complexities as of yet. Arguably, there are surprises in store as our understanding of the system develops and this warrants the seed for further research!