[能源議題] 相同發電量下. 各種能源的人命風險

一. 各種能源在相同發電量下的致死風險比較

參考自
http://www.forbes.com/sites/jamesconca/2012/06/10/energys-deathprint-a-price-always-paid/

大家都聽過各種能源的碳足跡, 排碳量最大的能源就是燃煤. 平均每一度電排900克的CO2. 兒風力和核能則是排碳最低的能源. 平均每度電15克. 而且這排碳主要是來自建設時所使用的混凝土. 鋼鐵. 以及鈾燃料的開採提煉. 生質能則被認為是吸排碳平衡的一種能源.

而各項能源的致死風險數據 - 每一度電會導致多少人命犧牲. 此數據很類似碳足跡. 煤是最嚴重的. 而風力與核能是最輕微的. 數據統計主要來自WHO, CDC. NAS的相關研究, 化石燃料與生質燃料對健康的不利影響. 事實上. WHO已經警告. 在發展中國家直接燃燒生質燃料已經成為全球性的健康問題.

以下是產生每兆度電力. 各項能源所造成的死亡人數
(包含直接致死以及由流行病學估算其影響)

Energy Source               Mortality Rate (deaths/trillionkWhr)
燃煤-世界平均            170,000    (提供全球50%的電力 )
燃煤-中國                    280,000    (提供中國75%的電力 )
燃煤-美國                      15,000    (提供44% 的電力)
石油                                36,000    (36%能源, 8%電力)
天然氣                              4,000    (提供全球20% 的電力)
生質燃料                        24,000    (提供全球21% 的能源)
太陽能 (rooftop)                  440    (< 1% global electricity)
風力                                     150    (~ 1% global electricity)
水力-世界平均                 1,400    (提供全球15% 的電力)
核能-世界平均                      90    
(提供全球17% 的電力. 包含車諾比及福島核災)

二. 燃煤和天然氣的危害更甚於核能

參考自
http://climate.nasa.gov/news/903
http://pubs.acs.org/doi/pdf/10.1021/es3051197

人為因素導致的空氣污染及全球氣候變遷. 燃燒化石燃料是主要因素. 要緩解這兩項大問題. 大量使用低碳能源 - 如核能和再生能源. 是一個有效率的方法

圖一: 以核能替代化石燃料所能避免的累積死亡總數. (Cumulative prevent deaths).
上方的圖表是以美國研究資料. 1971-2009的數據. 標示平均值和根據歷史事件所得到的基線
中間和下方的圖表則是以IAEA的數據對2010-2050的推算
中間為高規格核能供應
下圖為低規格核能供應
粗柱體是天然氣. 細線則是燃煤. 單位是百萬人

Figure 2. Mean net deaths prevented annually by nuclear power between 1971-2009 for various countries/regions. Ranges not shown but are a factor of ~4 higher and lower than the mean values.
各個不同國家區域裡. 自1971-2009. 使用核能替代化石燃料所減少的死亡數字

Using historical electricity production data and mortality and emission factors from the peer-reviewed scientific literature, we found that despite the three major nuclear accidents the world has experienced, nuclear power prevented an average of over 1.8 million net deaths worldwide between 1971-2009 (see Fig. 1). This amounts to at least hundreds and more likely thousands of times more deaths than it caused. An average of 76,000 deaths per year were avoided annually between 2000-2009 (see Fig. 2), with a range of 19,000-300,000 per year.
根據歷史發電數據. 致死率. 氣體排放因素. 我們發現如果不計算三大核災事故. 在1971-2009之間. 使用核能能減少平均180萬的死亡人數. 而實際數字可能是這個的百倍甚至千倍. 在2000-2009之間. 每年可以減少19000-300000的死亡人數

Likewise, we calculated that nuclear power prevented an average of 64 gigatonnes of CO₂-equivalent (GtCO₂-eq) net GHG emissions globally between 1971-2009 (see Fig. 3). This is about 15 times more emissions than it caused. It is equivalent to the past 35 years of CO₂ emissions from coal burning in the U.S. or 17 years in China (ref. 3) — i.e., historical nuclear energy production has prevented the building of hundreds of large coal-fired power plants.
同樣的我們計算. 在1971-2009之間. 使用核能可以減少640億頓的溫室效應氣體. 這個量大約是美國35年燃煤所排放溫室氣體的總和. 或是中國7年燃煤所排放溫室氣體的總和. 歷史上的核能發電已經減少了相當上百座的大型燃煤發電排碳


To compute potential future effects, we started with the projected nuclear energy supply for 2010-2050 from an assessment made by the UN International Atomic Energy Agency that takes into account the effects of the Fukushima accident (ref. 4). We assume that the projected nuclear energy is canceled and replaced entirely by energy from either coal or natural gas. We calculate that this nuclear phaseout scenario leads to an average of 420,000-7 million deaths and 80-240 GtCO₂-eq emissions globally (the high-end values reflect the all coal case; see Figs. 1 and 3). This emissions range corresponds to 16-48% of the "allowable" cumulative CO₂ emissions between 2012-2050 if the world chooses to aim for a target atmospheric CO₂ concentration of 350 ppm by around the end of this century (ref. 5). In other words, projected nuclear power could reduce the CO₂ mitigation burden for meeting this target by as much as 16-48%.
為了計算核能對未來的潛在影響. 我們根據聯合國IAEA對2010-2050所做出的估算(包含福島核災影響). 如果這段期間的核能發電全部取消. 改成燃煤或天然氣. 我們估算這會多出42萬到700萬的死亡人數. 並且將額外製造出800~2400億頓的CO2溫室效應氣體. 這個量相當於佔了2010-2050所允許全球排放量的16~48%

Figure 3. Cumulative net GHG emissions prevented assuming nuclear power replaces fossil fuels. The three panels are ordered the same as in Fig. 1, except that mean values for both the all coal and all gas cases are labeled. Error bars reflect the ranges for the fossil fuel emission factors listed in Table 1 of our paper.
使用核能取代化石燃料所減少的溫室效應排放量. 單位gigatonCO2-eq.

The largest uncertainties and limitations of our analysis stem from the assumed values for impacts per unit electric energy produced. However, we emphasize that our results for both prevented mortality and prevented GHG emissions could be substantial underestimates. This is because (among other reasons) our mortality and emission factors are based on analysis of Europe and the US (respectively), and thus neglect the fact that fatal air pollution and GHG emissions from power plants in developing countries are on average substantially higher per unit energy produced than in developed countries.
我們分析的最大不確定性源於對每單位生產電力能源影響的預設. 我們強調的是. 這個研究結果可能會對防止死亡數和防止溫室氣體排放量大幅低估. 這是因為我們數據是基於對美國和歐洲各國的分析. 而發展中國家的電廠產生的空氣污染和溫室效應氣體. 平均都將大於先進國家

Our findings also have important implications for large-scale "fuel switching" to natural gas from coal or from nuclear. Although natural gas burning emits less fatal pollutants and GHGs than coal burning, it is far deadlier than nuclear power, causing about 40 times more deaths per unit electric energy produced (ref. 2).
我們也發現. 大規模使用天然氣取代煤或核能. 會有重大關聯性. 雖然燃燒天然氣產生的污染和溫室效應氣體都低於燃煤. 但相對於核能它依然危險. 平均每單位電力會造成多出40倍的死亡數字

Also, such fuel switching is practically guaranteed to worsen the climate problem for several reasons. First, carbon capture and storage is an immature technology and is therefore unlikely to constrain the resulting GHG emissions in the necessary time frame. Second, electricity infrastructure generally has a long lifetime (e.g., fossil fuel power plants typically operate for up to ~50 years). Third, potentially usable natural gas resources (especially unconventional ones like shale gas) are enormous, containing many hundreds to thousands of gigatonnes of carbon (based on ref. 6). For perspective, the atmosphere currently contains ~830 GtC, of which ~200 GtC are from industrial-era fossil fuel burning.
並且. 以天然氣燃料為主實際上會加深氣候變遷問題. 其一. 碳捕捉和碳儲存技術尚未成熟. 因此初期並無法限制溫室效應氣體的排放. 其二. 發電廠都有相當長的使用期限(火力發電廠平均壽命約50年). 其三. 潛在可開採使用的天然氣資源(特別是頁岩氣)儲存量大. 包含數千甚至數萬億頓的碳. 現在的大氣中大約有8300億頓的碳. 其中2000億頓的碳是從工業時代開始累積至今


We conclude that nuclear energy — despite posing several challenges, as do all energy sources (ref. 7) — needs to be retained and significantly expanded in order to avoid or minimize the devastating impacts of unabated climate change and air pollution caused by fossil fuel burning.
結論 - 儘管需要面對一些挑戰. 為了避免或減少化石燃料所造成的氣候變遷和空氣汙染,核能是有必要保留下來並且顯著地擴大使用

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