Despite the threat of climate change, the world still consumes almost 100 million barrels of oil a day. Most of that goes on transport, burned in cars and trucks and planes. There’s no source of renewable liquid fuels that comes anywhere near that scale, and so the most obvious solution for transport has been electrification and renewable energy.
Ultimately, I suspect that most of the world’s transport will be electric, though we’re a long way off that. The bigger issue is that some things are easier to electrify than others. Electric cars are relatively easy, and we can build better batteries and charging networks to speed that transition. Heavy goods vehicles are more of a challenge, and aviation is the most daunting of them all. So far there is no way to make aviation sustainable, but the industry has every intention of growing regardless. We can encourage people not to fly, but that’s not gone so well on energy efficiency, eating meat or a hundred other elements of ethical living. There is a real need for innovation around greener and cleaner liquid fuels for planes.
Biofuels is one key area of research. Considering that the first commercial flight using biofuels was only 2008, progress has been quite fast. That was a Virgin Atlantic flight using a 20/80 mix of biofuels and conventional jet fuel, and the company has been experimenting ever since. Their latest idea uses a fuel made from waste industrial gases, and it is due to be tested this year.
The big problem with biofuels is that they require land, and we need land for crops. There is a real danger that biofuels could compete for land and crowd out food crops, and this was a known factor in the food price spike in 2008. That year, a third of the maize grown in the US was used for biofuels, while millions of people went hungry and over 20 different countries experienced food riots. It is the poorest that suffer most from rising food prices, and it is the richest who fly: aviation biofuels that use food crops are simply not ethical.
Fortunately, there are other avenues to explore. Advocates of biofuels have been saying this from the beginning, suggesting that food crops were only the first wave of innovation. Biofuels would evolve to use waste materials as part of a circular economy. Eventually we would be able to create them using algae, and we’re on the cusp of those technologies now.
This month the Norwegian environmental agency Bellona released a report into marine biofuels for aviation. There are many advantages to marine production, as I’ve argued before. Farming the oceans frees up land, saves fresh water, and reduces pressure on the soil. Farming seaweed can be integrated with fish production to create food systems that would restore marine biodiversity and create jobs in neglected coastal communities. It’s a huge opportunity, and one that not nearly enough people are talking about.
The sea is a massively under-used resource when it comes to food and energy production, and one of the big advantages is how space-efficient it is. On land, everything grows in one layer on the surface. At sea you can grow seaweed in the whole top 10 metres of water. You can grow 26 tonnes of dried seaweed in a hectare of ocean, compared to 5 tonnes of corn on a hectare of land. It’s also very fast. Bamboo holds the world record for the fastest growing plant on land, but Giant Kelp is twice as fast – under ideal conditions it can grow 50-60 centimetres in a single day.
What’s holding us back from exploiting these opportunities is that ocean farming hasn’t been mechanised the way land farming has. Because the market for seaweed is small and limited to certain food cultures, production is fairly low scale and labour intensive. To really make the most of it, we need the marine equivalent of tractors and combine harvesters. That’s going to need a concerted research and development agenda, international cooperation, and some serious funding.
Norway is leading on this so far – here’s a video from Seaweed Energy Solutions, which is trialing seaweed farming in Norway. Ocean Forest is another company exploring this idea. There are others in Japan, Ireland, and a small project in Scotland. It’s early days yet, but I suspect that fortunes will be made on ocean farming technologies in the coming decades.