氣候變遷對海島國家海域疆界影響之研究

政府間氣候變化專門委員會(IPCC)在2007年出版的第四次科學評估報告當中首次證實全球暖化的原因有九成是由於人類活動導致人為溫室氣體濃度增加所致，各大洲都已受到顯著的人為暖化影響，而氣候劇烈的改變對人類有著決定性的影響：全球暖化、乾旱、洪水、海平面上升、糧食危機與極端氣候，這些都正在加速發生當中。其中，氣候變遷造成的海平面上升問題為本文關注的重點。許多沿海國家與海島國家由於海岸侵蝕、淡水遭汙染以及國土被淹沒使得家園逐漸不適宜居住，導致環境難民等問題。　　海平面快速上升之下將造成低潮線的移動，根據《聯合國海洋法公約》，基線為一沿海國往外推算出海洋區域並獲得海洋權利的基礎，由於現行的《聯合國海洋法公約》並未明文規定基線的永久性，未來若是任何沿海國家因為氣候變遷造成低潮線的後退，致使海域疆界遭受影響時，原海域疆界應該維持或是根據當時的低潮線重新劃定海域疆界等問題國際社會尚未有明確共識，本文討論的重點將為分析歸納海域疆界維持與變動之優缺點，並且思考在未來可行的海域疆界「永久化」方式。　　海域疆界最易受到顯著影響的國家為低地海島國，因此在個案研究對象上本論文選擇兩個首當其衝的海島國家：位於印度洋之馬爾地夫共和國與位於太平洋之吉里巴斯共和國，藉著此二案例國家來說明最易受海平面上升影響的海島國家目前的環境狀況與歸納未來之因應政策。

關鍵字

氣候變遷；海平面上升；海域疆界；基線；海島國家

並列摘要

The Fourth Assessment Report: 2007 Climate Change of the Intergovernmental Panel on Climate Change (IPCC) first confirmed that 90% of climate change is caused by human activity. Climate change affects our environment different ways: global warming, drought, flood, rising sea level, food security and extreme weather. Among them, rising sea level and the problems it triggers are the main focus of this study. Lots of climate refugees have lost their homes owing to the coastal erosion, fresh water supply issues and land inundation. According to the United Nations Convention on the Law of the Sea, two kinds of baseline system are included. One is the normal baselines which are the low-water lines along the coast, and the other ones are straight baselines which mean baseline is the low-water line along the coast. Measured from baselines, every state can establish areas, obtain rights and jurisdiction. Nevertheless, the UNCLOS doesn’t explain if the baselines are permanent, which results in potential conflicts and disputes. This thesis is focused on analyzing the advantages and disadvantages of redrawing or maintaining maritime boundaries. Also, this research reconsiders the principle of making baselines under the situation of sea level raising and the possibility to freeze the boundaries. This study is particularly focused on island states and the livelihood of people in those states. Thus, the case studies are on two island countries: Maldives and Kiribati. By analyzing and introducing their governments’ strategies and adaptations, one of the purposes of this research is to find a way to deal with matters raised from climate change.