The promise of kelp-powered flight
Kelp is fast and relatively easy to grow, and already a vital food in many parts of the world. Martha Henriques asks whether it could also power the aircraft of the future.
From the US, to the UK and India, seaweed cultivation is seeing something of a renaissance.
It's become a livelihood and source of nutrition in parts of the world where it hasn't traditionally been part of the cuisine before, and is a fast-growing source of food production globally, with manifold potential uses in agriculture.
As well as cultivating seaweed for food, restoring degraded natural kelp forests could help restore ecosystems and help to deacidify the oceans. But might it also help people to travel the world too?
Catriona Macleod, deputy head of the Fisheries and Aquaculture Centre at the University of Tasmania's Institute for Marine and Antarctic Studies in Australia, describes seaweed as the "Swiss army knife" of tools to tackle planetary challenges.
One of those challenges is a sustainable source of fuel for aviation. The vast majority of flights are currently powered by fossil fuels, contributing nearly 2.5% of the world's carbon dioxide emissions, and around 3.5% when non-CO2 emissions are considered too. Renewable alternatives such as biofuels from crops on land come with their own sustainability issues, such as massive use of land and water, and harm to biodiversity. Seaweed, meanwhile, requires a fraction of the resources to grow, and has more than a decade of experiments as a fuel behind it.
But for all the enthusiasm about seaweed, it's not a miracle crop. The quantities of it required to fuel long-distance transport would be considerable. And, like anything, too much of it can bring a whole new set of problems and sometimes may even be a source of carbon emissions itself. Scaling up seaweed aquaculture is also a grand challenge in itself, as Macleod notes.
Join me in the third episode of Future Planet's video series New Directions, where we ask what it would take to power planes using seaweed.
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