日前英國財政大臣Gordon Brown委託前世界銀行首席經濟學家史登（Nicholas Stern）爵士進行關於氣候變化之經濟衝擊的一項研究評估報告指出，目前如不採取行動來緩和氣候變化，則所造成之損害成本將會高出許多；亦即越早行動越有可能減少未來損害的成本，而且如果排放減量政策設計良善，減量成本將處於可控制範圍內，史登估計全世界需投入全球國內生產毛額百分之ㄧ，否則未來將多付出5倍至 20倍以上的代價來彌補。
最近，「不願面對的真相」電影在全球播映，已引發很大的迴響。電影中最令人震驚的內容是：美國前副總統高爾提出北極格陵蘭島上的冰川，在21世紀內可能融解，屆時除許多海島與海岸國家將會淹沒外，美國佛羅里達州會大面積沉淪，而紐約、上海等重要都市也都將會被上升的海水入侵。同時，也提出大量淡水將進入北大西洋，可能使得海洋溫鹽環流受到干擾，全球有可能在快速增溫後進入數百年的小冰河期。這些內容，乃是近數年內幾份國際重要科學期刊論文的重點，更是2007年IPCC（政府間氣候變遷因應小組）發表第4次氣候變遷評估報告中，對於未來全球暖化下，最令人擔憂的衝擊面預估。
台灣位於亞洲大陸與太平洋交界處的海島國家，為受氣候變遷衝擊影響之敏感地區，氣候變遷直接衝擊全島之水文、水資源、農業生產與農業需水量、公共衛生及生態環境等。根據研究分析顯示，近年來台灣地區河川流量均具有極端化之趨勢，亦即豐水期流量增加，而枯水期減少，意即豐枯水期流量的差異變大，而台灣南部登革熱亦有逐漸北移之現象。另外，每年颱風、暴雨是台灣脆弱性環境需面對的問題。我們亟需關心處理的是要如何降低風險和損失，也就是如何降低台灣因氣候變遷的衝擊及做好調適。
根據德國慕尼黑再保險（Munich Re）統計，2005年全球因氣候災害造成的經濟損失約為2,040億美元，約為1998年經濟損失的兩倍。而保險損失同樣高達920億美元，則為歷年之最。其中，颶風卡崔娜(Katrina)所造成的財產損失總計超過1,250億美元及600億美元的保險損失。根據我國保險事業發展中心之統計，台灣的颱風及洪水保險損失由2003年的新台幣2,700萬元增加至2005年的12億6,700萬元新台幣，約增加47倍。
因此，我們可以感受到我們面臨的氣候變遷越來越大，也需要投入更多的氣候變遷預測模擬及調適策略之研擬及推動經費，我們需要更積極地發展與改善氣候變遷預警系統，如颱風預警系統、旱災預警系統、洪水預警系統、土石流預警系統等等，並積極地推動全民防災系統，對於經濟的衝擊和調適，則是我們未來需進一步強化的重點，這是我們長期需努力的方向。
自2005年2月京都議定書正式生效後，世界各國對於如何減緩氣候變遷及溫室氣體減量，已展開熱烈的對話與行動。台灣為因應此一國際環保議題，陸續召開全國能源會議、國家永續發展會議及經濟永續發展會議，就我國能源政策及溫室氣體減量策略進行檢討，並在行政院通過「溫室氣體減量法」草案；台灣將依據聯合國氣候變化綱要公約精神，以有效及最低成本的方式，來防制氣候變遷及推動溫室氣體減量，並追求永續發展。
環保署表示，溫室氣體減量法(草案)之立法原則包括：承擔共同但有差異的責任，以成本有效及最低成本來防制氣候變遷，並追求永續發展。因溫室氣體減量工作非一蹴可及，該法案規範漸進式的推動減量：漸進調整減量能力，如提升能源效率及發展再生能源、進行產業之溫室氣體盤查登錄及查證、溫室氣體排放效能標準管理，再逐步進入總量管制與排放交易制度。法案將作為國內整合決策機制及參與國際合作之橋樑，藉此降低決策的相對不確定性，並透過立法來展現我國推動溫室氣體減量之立場與決心。
環保署強調，台灣國際地位特殊，由於未能成為聯合國會員國，無法簽署聯合國氣候變化綱要公約與京都議定書，但台灣為海島國家，對於氣候變遷所造成的衝擊影響將不可避免，故積極推動溫室氣體減量，絕對是「現在不做，明天會後悔的工作」。
◎ 本文發表於11月3日台灣環保署與英國貿易文化辦事處代表處聯合記者會上。
According to the recent report on the economics of climate change by former World Bank chief economist Sir Nicholas Stern, commissioned by British Chancellor of the Exchequer Gordon Brown, if no action is taken now to mitigate climate change, the costs from the resulting damages would be much higher; therefore, early action could reduce the costs of damages in the future. If emissions reduction policies were well designed, the reduction costs would be manageable. Stern estimates that the world need to spend about 1% of global GDP now, or pay for the costs that would be 5 to 20 times in the future.
The recent worldwide release of the movie "The Inconvenient Truth" has triggered large response. Former U.S. Vice-President Al Gore raised the shocking scenario of the Greenland ice sheet possibly melting within the 21th Century, not only sinking many island and coastal countries, but also inundating the state of Florida and major cities such as New York and Shanghai. At the same time, large amount of freshwater would enter the North Atlantic Ocean and interfere with the thermohaline circulation, possibly bringing the world into a little Ice Age that would last hundreds of years. These are the focus of some major international scientific journals in recent years, as well as the 2007 Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report, assessing the worrisome impacts of global warming in the future.
Taiwan is an island country situated between the Asian continent and the Pacific Ocean, an area sensitive to the impacts of climate change, directly affecting the hydrology, water resources, agricultural production and water use, public health and ecology of the entire island. Research has shown that in recent years, the average river flow in Taiwan is becoming more extreme, with more flow during wet season and less flow during dry season, and the occurrence of dengue fever in southern Taiwan is gradually moving north. Furthermore, our vulnerable environment faces the problems of typhoons and storms every year. We urgently need to be concerned with how to lower risks and damages, and that is how to reduce the impacts of climate change on Taiwan and to prepare well for adaptation.
According to the statistics of Germany's Munich Re, global economic losses from climate-related disasters totaled about US$204 billion in 2005, twice that of 1998, and insurance losses reached a historical high of US$92 billion. Of the total, Hurricane Katrina caused financial losses of more than US$125 billion and insurance losses of US$60 billion. According to our insurance industry statistics, insurance losses from typhoons and flooding in Taiwan rose from NT$27 million in 2003 to NT$1.267 billion in 2005, an increase of 47 folds.
We can feel more and more climate change and need to spend more on climate change prediction modeling and more budget on adaptation strategies. We need to more aggressively develop and improve climate warning systems, such as typhoon, drought, floods, and landslide warning systems, as well as promote a national disaster prevention system. We need to focus more on economic impacts and adaptation, and this is the direction of our long-term efforts.
Since the entry into force of the Kyoto Protocol in February 2005, countries worldwide have started dialogue and action on mitigating climate change and reducing greenhouse gas emissions. In response this global environmental issue, Taiwan convened the National Energy Conference, National Sustainable Development Conference, and Conference on Sustaining Taiwan’s Economic Development, in order to review our energy policy and greenhouse gas reduction strategies, and the Executive Yuan also passed the draft “Greenhouse Gas Reduction Act”. In accordance with the spirit of the United Nations Framework Convention on Climate Change (UNFCCC), Taiwan will mitigate climate change and reduce greenhouse gases with cost-effective and least-cost methods and pursue sustainable development.
Taiwan EPA indicates that the principles of the draft Greenhouse Gas Reduction Act include: common but differentiated responsibility, preventing climate change with cost-effectiveness, and pursuing sustainable development. Since efforts to reduce greenhouse gases cannot be done in one step, the Act provides gradual promotion of reduction: adjusting reduction potential, such as increasing energy efficiency and developing renewable energy, implement industrial greenhouse gas accounting and reporting, and greenhouse gas efficiency indicator management, then move toward a cap and trade scheme. The Act will serve as a bridge between domestic integrative policy-making mechanism and international cooperation, in order to reduce uncertainty in policy-making, and through the legislation process, to show our position and determination to promote greenhouse gas reduction.
Taiwan EPA emphasizes that due to Taiwan's unique international status, we still are not able to become a member of the United Nations, and thus cannot sign the UNFCCC and the Kyoto Protocol. However, as an island country, Taiwan cannot avoid the impacts of climate change, and if we do not proactively promote greenhouse gas reduction today, we will regret it tomorrow.
