Commentary on the Contribution to Greenhouse Gas Absorption by the Forestry Sector in Taiwan

In Taiwan, 59% of area (i.e., 2.15 million ha, or 5.3 million acre) is covered by forests, less forested than some developed countries like Sweden (70%), Japan (67 percent) and South Korea (64 percent). More significantly, forest resources contribute to greenhouse gas (GHG) emission reduction and climate change mitigation by removing atmospheric carbon dioxide (CO2) and storing it in biomass and other carbon pools. According to the national GHG inventory, the percentage of contribution to GHG absorption by forestry sector in Taiwan are only about 7.4% based on total GHG emissions (284,514 kilotons of CO2 equivalents) in 2013. On the other hand, the Greenhouse Gas Reduction and Management Act (GGRMA) has been officially promulgated on 1 July 2015. In the paper, the author first described the brief of the GGRMA regarding the role in the Taiwan’s forestry sector. Thereafter, the contribution to GHG absorption by forestry sector in Taiwan was analyzed according to the “2015 Taiwan Greenhouse Gas Inventory“. Finally, some perspectives were addressed to enhance carbon sequestration by the forestry sector in Taiwan.


Introduction
It is well known that global warming could be caused by the emissions of greenhouse gases (GHG) from anthropogenic activities that may be the most significant driver of observed climate change since the mid-20 th century. These GHG compounds contain carbon dioxide (CO 2 ), methane (CH 4 ), nitrous oxide (N 2 O), and fluorinated gases. On the other hand, land use and management will influence a variety of ecosystem processes that affect GHG emissions and absorption, such as photosynthesis and combustion (or forest fire). These processes mainly involve transformations of carbon that is driven by the biological (e.g., activities of plants), thereby acting as atmospheric CO 2 sink, carbon stocks or carbon pools. The key greenhouse gas of concern is carbon dioxide (CO 2 ). CO 2 fluxes between the atmosphere and ecosystems are primarily controlled by uptake through plant photosynthesis. According to the "2006 IPCC Guidelines for National Greenhouse Gas Inventories" [1], CO 2 fluxes in the Forestry and Other Land Use sector can be estimated in the following way. The use of carbon (C) stock changes to estimate CO 2 emissions and removals is based on the fact that changes in ecosystem C stocks are predominately through CO 2 exchange between the land surface and the atmosphere. Hence, the annual increase in total C stocks is equal to net removal (absorption) of CO 2 from the atmosphere, while the loss in total C stocks (e.g., harvested wood products) are equated with net emission of CO 2 .
In Taiwan, nearly 60% of area (i.e., 2.20 million ha, or 5.3 million acre) is covered by forests, according to a government forest resource and land use survey [2]. More than 70% of Taiwan's forests primarily contain hardwood trees (i.e., 1.54 million ha), just more than 14% contain conifers (i.e., 0.30 million ha) and about 8% contain mixed hardwood and conifers (i.e., 0.17 million ha). The remaining forested area contains mostly bamboo (i.e., 0.18 million ha). More significantly, forest resources are useful tools against global warming because they can absorb large quantities of CO 2 from the atmosphere. According to the report by the International Energy Agency [3], Taiwan is a major GHG country. The country's CO 2 emissions from fuel combustion only more than doubled from about 110 million tons in 1990 to 250 million tons in 2014. The amount of CO 2 emission per capita in 2014 is 10.7 tons, as compared to 5.5 CO 2 tons per capita in 1990.
In order to cut GHG emissions significantly in the near future, the Greenhouse Gas Reduction and Management Act (GGRMA) was passed on 15 June 2015 by the Taiwan's congress. The act sets a mandatory reduction target for Taiwan's overall GHG emissions and also provide the way for a carbon cap-and-trade system to be established in Taiwan. In this regard, the forestry sector in Taiwan will play a vital role in the GHG absorption and climate change adaptation.

Brief Description of the GGRMA Regarding the Role in the Taiwan's Forestry Sector
In Taiwan, the GGRMA was officially promulgated on 1 July 2015, providing a legal basis for mitigating GHG emissions, and also stipulating the carbon reduction targets in Taiwan. The Act aims at establishing strategies to reduce and manage GHG emissions, strengthening environmental justice, and the shared responsibility of environmental protection and sustainable development. In this regard, it groups 34 articles into six chapters, including general principles, authority and responsibility of government agencies, emission reduction measures, education and grants, penalty provisions, and supplementary provisions. In addition, the Environmental Protection Administration (EPA) is the central competent authority, which charges it with formulating national climate change guideline and action programs to reduce GHG emissions response. More significantly, long-term national GHG emission reduction goal in Taiwan stipulated by the Act shall be to reduce GHG emissions to no more than 50% of 2005 GHG emission by 2050.
To meet global GHG emission reduction strategy, the central competent authority has formulated "Healthy Forest Carbon Management" as a comprehensive target under the Forestry Act. The policy entails implementation of three management strategies: carbon sequestration, carbon conservation, and carbon substitution. Active ways towards "Healthy Forest Carbon Management" are good forest management and expansion of reforestation. For example, the Taiwan government has actively encouraged "Afforestation in the Flat Area" and "Green Afforestation" projects that targets abandoned farm and lands. In the past two decades (1992-2012), total reforestation area with hardwoods has reached over 120,000 ha. Planting trees will increase absorption of CO 2 from the atmosphere. Regarding the role in the Taiwan's forestry sector, the relevant central government agencies, including the Forestry Bureau and the Taiwan Forestry Research Institute under the Council of Agriculture, be shall promote GHG reduction and climate change adaptation through the following actions: Forest resource management, biodiversity conservation, and strengthening of forests' carbon sequestration. Under the promulgation of the GGRMA, the Forestry Bureau in Taiwan must actively promote reforestation in the near future by providing economic incentives for the farmers. In addition, the GHG offset project operators may request the central competent authority (i.e., EPA) to issue reduction credits representing emission reductions (including carbon sinks) verified by verification bodies. According the definition by the Act, carbon sink means any process or mechanism, which removes a GHG from the atmosphere such as trees and forests.

The Contribution to GHG Absorption by Forestry Sector in Taiwan
According to the 17th Convention of the Parties (COP17) of the United Nations Framework Convention on Climate Change (UNFCCC), the national GHG emissions inventory in Taiwan has been carried out in accordance with the "2006 IPCC Guidelines for National Greenhouse Gas Inventories". Table 1 summarized the annual statistics on total GHG emissions, net GHG emission and GHG absorption by the forestry sector in Taiwan since 1990 [4] is based on It can be seen that total GHG emissions in Taiwan increased from 136, 178 kilotons of CO 2 equivalents in 1990 to 284,514 kilotons of CO 2 equivalents in 2013, which is equivalent to the increase by about 109% at an annual growth rate of 3.0% on average. By contrast, net GHG emissions in Taiwan increased from 116,913 kilotons of CO 2 equivalents in 1990 to 263,445 kilotons of CO 2 equivalents in 2013, with GHG emissions by 125% and an average annual growth rate of 3.2%.
In Taiwan, the main source of GHG absorbed by land use and forestry sector is carbon dioxide (CO 2 ) and the annual carbon stock increase from forestry resources. According to the "2006 IPCC Guidelines for National Greenhouse Gas Inventories", carbon pool stored in forest should include biomass, dead organic matter (including dead wood and litter) and soil organic matter. The contribution to the GHG absorption by the latter two sources was assumed to be ignorable in the "2015 Taiwan Greenhouse Gas Inventory". The GHG emission and absorption by land use and forestry sector for Taiwan from year 1990 to 2013 (mainly consists of CO 2 absorption by forestry resources) is shown in Table 1. Herein, the GHG emissions (year-on-year loss) from existing forests include wood removals (harvest), fuel wood, and disturbance (e.g., typhoon, forest fire, illegal logging, and reclamation). For example, the loss value in 2009 (i.e., 2,753 kilotons of carbon dioxide equivalents) was caused by the Typhoon Morakot, which was the deadliest typhoon to impact Taiwan on August, triggering enormous mudflow, severe flooding and hill slide [5]. On the other hand, the term "other lands turned to forests" means the biomass increase by afforestation and reforestation in the plain area. In 2013, the CO 2 absorption by the forestry sector was 21,069 kilotons of carbon dioxide equivalents, up by 26 kilotons of carbon dioxide equivalents compared to that in 2012 (0.13%). The CO 2 absorption between 1990 and 2013 was increased to about 9.4%, which is equivalent to an average annual growth rate of 0.39%.

Conclusions and Perspectives
Sustainable forest management not only reduces GHG emissions from deforestation and forest degradation, but also provides an adaptation pool for air quality and bio resource activity. Thus, as international concerns about climate change and CO 2 emission mitigation have increased, the central government agency in Taiwan (i.e., the Forestry Bureau) must shift the focus of afforestation and reforestation from helping farmers and stabilizing hill slopes to sequestering carbon by existing forest resources and other plain lands turned to forests.
It is especially of significance that the Greenhouse Gas Reduction and Management Act (GGRMA), promulgated on 1 July 2015, shall provide the legal basis for the Taiwan's GHG reduction target for the year 2050. As the forest resource is only sector for carbon sequestration in the calculation of national GHG inventory, the following perspectives can be drawn below.