Ocean & Climate
The neglected climate ally
Oceans are the 500-lb gorilla in the climate discussion and get precious little air time considering. Everyone knows that oceans cover two thirds of the surface of the earth. Fewer people know that the oceans have taken up a third of our carbon emissions and over 90% of the additional heat that has been trapped by anthropogenic warming. Landlubbers that we are, we have paid much less attention to the problems of over-exploitation of ocean resources and it hasn’t been until very recently that people have begun to think of oceans as providing an opportunity set. Whilst still nascent, we are at least seeing the emergence of some funds specifically focussed on the commercial and sustainability opportunities around oceans - the pioneering AquaSpark, Mirova Sustainable Oceans Fund, S2G Seafood Fund, SWEN Blue Ocean Partners, and Oceans14. I’ll take a closer look next week at some ocean-based climate solutions.
For this week’s Notes, I tuned into Peter de Menocal, director of Woods Hole Oceanographic Institute on Columbia Energy Exchange and Dr Ayana Elizabeth Johnson, founder of Urban Ocean Lab on the Vox podcast.
Oceans contain 40 times the amount of carbon as the atmosphere
Oceans take up about a third of carbon emissions, but fully 93% of the increase of heat energy (due to water’s much higher specific heat capacity - it takes more energy to warm 1kg of water 1 degree than 1kg air)
The oceans absorb carbon by reacting to form carbonic acid (H2CO3), which is gradually moved from the surface down to the deep ocean on the ocean conveyor belt, where it can stay for a long time - water tested on the sea floor shows carbon absorbed from the atmosphere from around 2000 years ago
Oceans aren’t just important for marine life and several hundreds of millions of people directly dependent on fishing; they are responsible for global patterns of weather, precipitation, strength of storms born at sea and regional temperatures [writing from a temperate, high-latitude location in Ireland thanks to Gulf Stream]
Climate change creates a number of inter-related ocean challenges:
Warming - causes coral bleaching, but also contributes to changing currents
Acidification - through the absorption of carbon dioxide to form carbonic acid, makes it more difficult for crustaceans to form shells and disorientating for other marine life. The PH of the ocean has already changed measurably.
Sea rise - through two vectors - melting ice shelf / glaciers and thermal expansion (just getting bigger as it warms)
Changing currents - with warming and reduced salinity with glacier melt, decreases the density of the water and imperils the big ocean conveyor belt that takes water down from the surface at the poles
Deep ocean currents supply upwelling of nutrient-rich cold water on which vital parts of the marine ecosystem depend - e.g. anchovy fisheries in Peru
We still have a lot to learn about the ocean and its mechanisms - we can’t tell to within a 100% margin of error how much carbon passes through a given ocean layer and we’ve only mapped 20% of the ocean floor in any detail.
One of the most important efforts to understand the state of the oceans is the Argo project, which now has almost 400 buoys that pogo through the various depths of the ocean taking measurements along the way and transmitting data at the surface. (Also check Saildrone.)