Frequently Asked questions:
Q: When you burn the fuel from kelp, doesn’t that increase the CO2 in the atmosphere?
A: The carbon in the kelp is absorbed CO2 from the ocean surface waters over the ninety-day harvest cycle. That CO2 in the ocean was recently absorbed from the atmosphere. So when kelp-derived fuel is burned, the CO2 emitted replaces only CO2 that was absorbed by the farms a few months previously, making a carbon-neutral cycle. (For further explanation, see discussion below on the Water Cycle, the Carbon Cycle and Fossil Carbon.)
Q: Is there a way for ocean farming to sequester CO2 out of the atmosphere?
A: Once ocean farming of kelp has replaced all fossil-fuels, then we might want to process additional kelp into bio-oil. The oil can be injected into old petroleum wells for future use if needed. This is important because it extracts the nutrients from the kelp before it is sequestered. We cannot afford to take nutrients out of the nutrient cycle by sequestering them.
Discussion
Water Cycle:
Consider the water cycle often taught as part of grade school curriculum. The sun evaporates water out of the ocean into the clouds and clouds drift over the land. The clouds then rain over the mountains and fields. The water eventually makes its way downstream and back into the ocean where it is once again evaporated, and the water cycle continues.
Carbon Cycle (see Fossil Carbon below):
The carbon cycle is a similar cycle to the water cycle. The carbon is absorbed by plants and trees from the atmosphere. If people (consider the early pioneers) cut down the trees and burned them for heat, the carbon is released into the atmosphere where it is absorbed by the trees again. Eventually those new trees might be cut down again for heat. Or the trees may live a full life, die of natural causes and decompose. The carbon escapes into the atmosphere where it is later re-absorbed by younger plants and trees. Either way, whether the trees are deliberately burned or they slowly rot, these are both examples of carbon continuing through the cycle.
In our kelp example, the carbon will be absorbed from the ocean by kelp on the ocean farms. The kelp can be turned into fuel. When the fuel is burned, the carbon is released into the atmosphere, then re-absorbed into the ocean and by the kelp on the farms. The carbon stays in the carbon cycle. Thus the kelp fuel is carbon-neutral.
Fossil Carbon:
Fossil carbon comes from deep sources and includes oil and coal taken out of geologic formations. When oil or coal is burned, it is not carbon-neutral, because the carbon is newly introduced to the current geologic period. When fossil carbon is burned, it increases the amount of carbon in the atmosphere and overwhelms the ability of the modern environment to absorb it. This excess CO2 absorbs infrared and warms the planet. Our oceans have been absorbing excessive fossil carbon for many years, which has been making the oceans more acidic. This makes is difficult to form shells and some species have been severely damaged. Until society stops burning fossil fuels, the problem will get worse.