3.3.6 Deforestation and Non Transportation Industrial Use of Halocarbons
Deforestation is responsible for about 10% of the total GHG forcing, mostly due to carbon dioxide emissions from burned trees and from the carbon dioxide that these trees could have removed from the air had they lived to maturity. Unfortunately, deforestation to clear land for agriculture and development continues today at a rapid pace in much of the world, including the Amazon, Indonesia and the boreal forests of Canada and Russia (89). A few projects here and there to protect a limited amount of old growth forest will make little difference in the end.
About half the halocarbon forcing (5%) is due to leaking refrigerants from vehicles already mentioned. The rest (5%) comes from leaking refrigeration units in buildings and from industrial use of these chemicals for other purposes.
3.3.7 Removal of Carbon Dioxide from Ambient Air by Stimulating Phytoplankton Growth or by Protecting/Increasing Existing Forests
Since trees and other green plants remove carbon dioxide from the air and convert it to plant tissue as part of photosynthetic reactions, some have suggested that growing more trees would help solve the global warming problem by lowering the ambient carbon dioxide level. The problem with this solution is that to make a meaningful difference, an area larger than the size of Europe with no present vegetation cover would have to be planted with trees. In addition to the facts that trees require a great deal of water and nutrients to grow to maturity and that the costs of providing each of these would be prohibitive, there is no land available on which to grow these trees or other plants save the deserts, which by their nature are unsuitable for large-scale plant growth (17, 53, 54, 90).
A similar solution which has been proposed is to add iron to areas of the ocean that are iron-deficient to stimulate phytoplankton production and thus remove carbon dioxide from the air via the gradient between the surface of the ocean and the air (17, 52-54, 91, 92). According to proponents of this solution, when the phytoplankton die, they would sink to the bottom of the ocean and the carbon removed from the air would remain there The area targeted is the Southern Ocean, between 30?S and Antarctica.
Calculations and preliminary experiments have shown this may be possible, but other nutrients like nitrogen may prove to be limiting also and if so, would be prohibitively expensive to apply (93). There are also concerns about harmful effects on sea-life from fertilizing the ocean. Finally, not enough carbon may be removed to make any difference (94) and that which is may not sink to the bottom as dead biomass, but recirculate in the upper layers of the ocean, eventually becoming oxidized and releasing its carbon back into the air as carbon dioxide, defeating the purpose of the treatment.
Utilities and other energy companies, in anticipation of future regulation of emissions, have begun using some of the options included in the Kyoto Protocol to offset their emissions by buying small tracts of forests in other countries and guaranteeing that these trees will grow to maturity, thus maximizing the carbon they will store (78). And as previously mentioned, some of the developed countries subject to Kyoto targets, including the U.S., have tried to or have succeeded in being allowed to use their own forests as offsets for fossil fuel emissions.
We believe that these kinds of activities will turn out to be largely ineffective, since they only marginally impact deforestation. They may work on a small-scale, e.g., for a single power company or a single power plant over the long-term and they may work on a large-scale for a short period of time, e.g., for those countries attempting to meet the First Commitment Period targets of Kyoto. But in each case, they fail to solve the long-term climate change problem by not reducing GHG emissions.
