The next question is naturally to analyze the actual carbon capture potential of these biomes: 1. oceans, 2. land surfaces, and 3. forests.

Oceans. With largest surface and mass among the three, world’s oceans are already the largest carbon store on earth (save for the subterranean deep carbon in core, mantle, and crust). Through the process of carbonation, oceans already absorb some 30% of all man-made CO₂ emissions every year. Thus, on surface, increasing ocean’s carbon capture appears attractive.

However, when studying this closer it becomes quickly obvious that ocean’s absorption capacity is limited and we have started to cross their limits. You can already see its negative consequences in ocean acidification from the excess carbonic acid. This impacts all marine life forming shells and skeletons (e.g. corals, mollusks, many planktons) and is already disrupting several oceanic nutrient cycles. Most visible impact is the coral reef bleaching (reduction in carbonate ions hinders development of coral’s calcium carbonate structure). Hence, any technology aimed at increasing CO₂ absorption into oceans has a high likelihood of being harmful and is truly a two-edged sword – particularly if done at scale.

Land Surfaces. The second largest mass and surface area are in the world’s land terrains and topsoil. Unfortunately, they fail badly in the third requirement, efficiency. By its nature soil is quite inert: gas-to-solid exchange is very different from gas-to-liquid exchange. Indeed, all the existing techniques for forcing carbon absorption into terrain are difficult and expensive. (There are some interesting, carbon-related agricultural practices that are quite efficient, but their scale is limited due to lack of suitable arable land.)

Thus land biomes capacity to absorb carbon in topsoil is likely to be low. This is true for tundra, deserts, shrublands and grasslands which cover almost all of the non-forest land biomes.

Forests. This leaves forests and interwoven wetlands as the main viable alternative. They also have very large surface areas and heavy mass, and very fortunately turn out to have an efficient technology for capturing carbon – photosynthesis. Indeed, conceptually forest can be thought as the reverse combustion engine: instead of drawing on existing carbon stocks and emitting CO₂ into atmosphere, forests absorb atmospheric CO₂ and store it in inert, usable, solid cellulose fibres.

In addition to the required physical characteristics, they also have a number of other beneficial features:

Societal benefits. Forests bring many secondary benefits in the form of biodiversity, water management, oxygen generation, environmental improvement, multiuse etc.

Proven, efficient technology. Forests’ technology is established and has been thoroughly tested – photosynthesis has been around for about 3.4 billion years. Similarly silvicultural science, the process of growing and cultivating, is well known and established.

Large scale. Forests cover approximately one quarter of the landmass and already absorb about 15.6 billion tons of the emitted carbon dioxide every year– over half of all fossil-fuel based emissions.  (Unfortunately, due to deforestation, fires, and other disturbances forests also release 8.1 billion tons of carbon dioxide, leaving the net absorption at 20% of all anthropogenic emissions.)

Economic. The process is highly economic. When done correctly achieving tree growth is cheap. Furthermore, on those numerous cases when the resulting cellulose, semi-cellulose and timber fibres can be used in the industry, the cost of carbon capture is actually negative.

Thus, after the foundation had studied a myriad of technological options, large scale carbon capture via forests was found to be by far the most attractive prospect. The next question was then to considered the relative opportunity in each of the three forest biomes: Tropical, Temperate, and Boreal forests.