Subsequently, Iceland is on track for meeting Kyoto's higher targets and their successfulness at carbon sequestration means afforestation and soil conservation are considered feasible techniques within the role of mitigating climate change.
4-5 millions trees were being planted annually by the 1990s and by the 2000, 84 million trees had been planted in total (Lal 2009). The government also increased the budget for afforestation by €6m in 2000 (Sigurdsson and Snorrason 2000) with the sole purpose of improving carbon sequestration.
The following table illustrates Iceland's carbon budget on a yearly basis:
| Process | Quantity (Tg C yr−1) |
|---|---|
| I. Sources | |
| 1. Degassing from volcanoes | 0.33–0.60 |
| 2. Anthropogenic emissions in 1990 | 0.55–0.70 |
| 3. Erosion-induced emissions | 0.01–0.02 |
| Total Sources | 0.94–1.42 |
| II. Sinks | |
| 1. Permanent uptake by Ca+2 and Mg+1 | 0.29 |
| 2. SOC sequestration in restoring eroded soils | 1.0 |
| 3. Above ground biomass C in vegetation | 0.2–0.6 |
| 4. Emission avoidance from erosion control | 0.01–0.02 |
| Total Sink | 1.50–1.9 |
Table 1: Lal 2009.
If estimations are correct, Iceland is now an emissions free nation!
| So how much carbon will changing forestry practices actually remove then? A paper by Nilsson and Schopfhauser (1995) calculated potential changes in the carbon cycle with a large-scale, global afforestation effort. They estimated a total of 345m ha of land is available for planting, but they also ensure their proposal is socially, economically and politically feasible, therefore substantially less land is really available for plantations and agroforestry. Nilsson and Schopfhauser confirmed it would take a very long time in order to fix reasonable amounts of carbon both above and below ground - this is summarized in table 1 below: Year MAI Annual carbon (million m3/yr) fixation (million t/yr) 2015 1122 407 2025 1784 635 2035 2411 864 2045 2734 991 2055 3112 1140 2070 3000 1092 2085 2879 1058 2095 2918 1084 (Source: Nilsson and Schopfhauser 1995) The effects of afforestation would only be significant after 40-50 years, and would stabalise after 60 years (2095), removing 1.5Gt per annum. Unfortunately, the authors conclude this is less than half of the 3.8Gt or carbon which is currently emitted each year, but, could sequester around 30% of anthropogenic emissions. So overall then.. Afforestation is certainly not a short term solution! And not all that effective (at least for half a century), feasible or measurable either. Generally there is no consensus on how much afforestation is required to offset emissions, as shown in the table below:  (Source: Andrasko 1990) There are many constraints; the more difficult probably being social reasons. Planting trees soley to uptake carbon is a difficult concept to apply in practice. Grainger (1991) summarised this by saying "even if environmental quality and economic productivity are both low, those who use the land may be unwilling to convert it to forest". However, environmental constraints also exist, especially when reforesting in the tropics where much of the soil is degraded, and also in terms of climate suitability. Additionally, it is also important to select the correct type of tree (as seen with China) if afforestation programs are to succeed, to ensure survival and long term sustainability. It can be effective, as illustrated by Iceland but this may only be due to their small economy. It could potentially be good coupled with another geoengineering technique(s), as any increase in forest biomass will sequester CO2, but alone could not deliver the means to solve the emissions problem. | |
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