Hidden connections: how whales affect the climate

One of the most interesting concepts touched upon by JB MacKinnon in his book The Once and Future World was that the role of animals in regulating planetary systems. George Monbiot has also recently written a fantastic piece on this – the following being a quote from Monbiot’s article Why whale poo matters:

Large carnivores can transform both the populations and the behaviour of large herbivores. In turn this can change the nature and structure of the plant community, which in turn affects processes such as soil erosion, river movements and carbon storage. The availability of nutrients, the physical geography of the land, even the composition of the atmosphere: all now turn out to be affected by animals. Living systems exert far more powerful impacts on the planet and its processes than we suspected.

The example used by both MacKinnon and Monbiot is how the presence of whales, a top-order predator, effects both the abundance of fish and other marine species as well as regulating the climate. The following clip developed by Monbiot and Sustainable Human gives a good overview of this this:

Basically the presence of whales actually increases the number of fish and plankton. Plankton has the ability to capture and storage of carbon from the atmosphere and is hence of interest to scientists looking at ways to mitigate effects of global warming.

In fact a number of geo-engineering “solutions” are being now looked at to mitigate the effects of global warming. These include ideas to spraying sulphates at high altitude to mimic the cooling effect of volcanoes or to use iron fertilisation of oceans to promote plankton growth and thus increase carbon removal from the atmosphere. Yet modelling of a number of these geo-engineering proposals have raised a number of concerns including the fact that all proposals will negatively affect large numbers of people. In contrast as stated in the video above, restoring whales to previous levels of abundance could act as a form of benign geo-engineering which will help reduce levels of carbon in the atmosphere.

Restoring ecosytems is one of the important steps that must be taken if we are to avoid destruction of a human habitable planet. Of course this will not solve the entire problem we face of a civlisation living beyond the means of our home.  Yet working with our planet seems a saner way to try and solve our problems, rather than blindly pumping chemicals into the oceans and atmosphere in the hopes that it will stave off effects of global warming.

Nor should we imagine that wolves and whales and wildebeest and plant plankton and sea otters alone can prevent the climate breakdown that the unchecked consumption of fossil fuels will cause. Annual plant growth cannot match the burning of fossil fuels, which mobilises the stored remains of many centuries of accumulated plant carbon every year. But these first inklings of the unexpected impacts of our destruction should provide yet another reason for treating the living planet gently. Everything is connected. – George Monbiot (Why whale poo matters)