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人民必須知道之事:民主政制下的能源政策

2018/11/23 — 14:48

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【文:Wade Allison 博士,牛津大學物理榮休教授】

English original text is beneath the translation. 

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廣告

聯合國跨政府氣候變化委員會 (IPCC) 上周發佈的報告(按:指 8/10/2018 發表的《 IPCC 全球升溫 1.5°C 特別報告》),重申了一個已經對許多人來說已經非常明確的事情:碳燃燒時代必須終結,我們的生活方式必須改變。。因此,我們正面對著一個歷史性抉擇:

  • 無視問題,期望他人在災難巨變來臨時自行做好準備;
  • 主動瞭解可能的替代方案,並且積極避免可能危及我們與下一代的狀況發生

經驗顯示,第一個選項是不切實際,且注定失敗的。在民主體制之內,無論怎樣困難也好,第二個選項是任何有能力的人都該作出的選擇。那現時有甚麼替代方案,而又該怎樣讓人簡單明白地瞭解這些方案呢?

廣告

讓我們先探究原則性的問題,把數字留到後面。

人類透過勇敢地控制火,而獲得了在地球上的生存優勢,這是其他動物從來沒有做到的。在前工業時代,人類所獲得的能量,都是源自太陽,透過風力、水力和植物生長間接取得。不過,(太陽能)供應的這幾種形式都有限制、微弱且斷斷續續。工業革命透過化石燃料取代了這些能源形式,而且蒸氣的力量讓人類的生活品質大幅改進,讓地球可以支撐的人口規模量大幅增長。而, IPCC  現在告訴我們這個想法其實有誤,燃燒各種含碳燃料——煤、油、天然氣或植物等——對現在人口量和我們期望的生活方式來說是不永續的。

那有甚麼選擇?我們或可選擇跟隨美國總統川普(按:港譯特朗普)的想法,否定 IPCC 提出的科學證據,但只有少數人會準備這樣做。

更普遍的作法,是重新起用前工業時代的能源,現稱再生能源。無疑,現代科技可在佔地   廣大的地方採集這些能源,但這些能源的供給來源仍一如既往地貧弱。要取代一個大型化石燃料電廠,需要佔地數百平方英哩的以百計大型風力發電機或密密麻麻的太陽能板。

另外也可在大型河流上建設水壩,不過這一方面會對生態造成傷害,另一方面又需大量遷移當地社區人口。類似的傷害已在尼羅河、長江、底格里斯河和湄公河出現,而合適河道本身也少,水資源本身也相當珍貴。這些「再生能源」會破壞環境,難以稱得上為「綠色」能源。

更嚴重地,再生能源間歇性這個老生常談的問題仍未解決:它們無法隨時隨地提供現代經濟需要的能源。部份意見認為,此情況可以根據「米高伯原則 (Micawber Principles) 」,期望最後「自然會有東西出現」來解決問題,但很明顯科學上就是有界限存在,例如由周期元素表上的元素,乃至電池科技發展。

科學其實早已提供另一能源:核能。核能最初由科學家亨利·貝克勒爾 (Henri Becquerel) 及瑪麗·居禮 (Marie Curie) 所提出,而且已被深入研究超過一世紀;現時已被部份人接受,但許多人仍然對其感恐懼。

同樣一公斤燃料相比起燃煤,核能產生接近 100 萬倍的能量,而且可以在任何時候與幾乎任何地點提供能量。核電廠既堅固佔地又小,只需小至 15 公頃土地,即可產生近 10 億瓦 (1GW) 輸出。那核能的安全性和對環境的影響呢?「看看車諾比(港譯:切爾諾貝爾)發生甚麼事吧!」是常會聽到的反應。

這宗 1986 年 4 月發生的意外,破壞烏克蘭大片土地,導致當地大量民眾撤離,但真造成大量破壞嗎?近年在當地拍下的野生動物照片記錄到在當地生活的生物正欣欣向榮,茁壯成長。雖然當地帶有輻射性,但總比之前有人類影響來得好。動物一定知道一些我們不知道的事情。華生可能會這樣說:「但牠們甚麼都不知道啊。」。福爾摩斯可能會這樣回應:「的確,但我們所知的也可能是錯的。」

Jorge Franganillo / flickr 
https://www.flickr.com/photos/46191841@N00/38546760946/

Jorge Franganillo / flickr
https://www.flickr.com/photos/[email protected]/38546760946/

逃出車諾比的人民當知道自己受輻射影響後,都感到十分恐懼,並且被告知需立即離開他們的家園。這種未曾見過及未加解釋的撒離,導致嚴重精神疾病,以及社會破壞,但最終這麼多撤離的人中只有 43 宗死亡是與核輻射本身有關: 28 位工人,以及15 位甲狀腺癌患者。大部份評論員所指的幾千宗死亡個案,以及無數荒廢土地的情況,從未發生過。

國際原子能機構和世界衛生組織在 2006 年發表報告揭露了這個真相,但未能在結論中指出輻射對健康的影響明顯誇大。結果就是類似人禍(編按:過度誇大)在 2011 年福島核事故中重現。雖然當時未有出現輻射致死個案,但不必要的撤離和恐懼,破壞力如同中世紀詛咒般,導致不少人受苦。福島事故後,全球採取了昂貴的經濟及技術程序,但車諾比的生物帶給我們訊息顯示這些步驟都是不必要的。

我已花了多年時間,了解生命怎樣會被輻射影響,以及人們為何對其產生恐懼。核能是非常強大的能源,即使是比起化學能源亦如是。兩者均是大自然的一部份,亦可被濫用為武器。核爆或會造成局部破壞和火災,但所釋放的輻射並非如同冷戰時鼓勵人們所相信的那種威脅。再者,核電廠也不可能如同核彈般爆炸,核電廠產出的微量廢料,在 60 年內也從未造成死亡個案。

那為甚麼輻射相對無害?由 35 億年前開始,生命已經演化出不同方法適應自然環境下的輻射,以及其他氧化物,特別是免疫系統能抑制癌細胞生長等。文明則沒有類似免疫力應對氣候變遷帶來的影響。人類文明的存亡將取決於社會是否能透過教育和公共衛生資訊的改變,以廣泛接受核能。情況類似人類祖先數千年前控制火一樣。

一個有見識的社會,若能為中弱輻射劑量訂立一個簡單的安全界限。這個簡單的安全界線將可以倍速與節省一半成本地佈建出新一代小型區域核電廠來提供核能,以提供海水淡化、氫氣生產和區域供暖。透過設立簡單的界限也可以因為對核電的廣泛理解,大幅縮減核能在經濟及監理的障礙。

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"Energy in a democracy: people need to know"

The report from the IPCC published last week tells us what is already becoming clear to many, namely that the era of carbon burning should end and that our way of living will change. So we are faced with a historical choice:

  • ignore the problem and expect others to be prepared when extraordinary disasters occur;
  • engage personally in understanding the alternatives and be proactive in preventing conditions overwhelming us and our children.

Experience shows that the first is unrealistic and is bound to fail. In a democracy the second is the choice that everyone who is able should make, however difficult that may seem. What are those alternatives and how may they be simply understood?

Look first at the principles and leave the numbers until later.

Mankind gained ascendency on Earth when he dared to domesticate fire, a step that no other animal ever made. Energy in the pre-industrial period came from the Sun via the wind, water power and the growth of vegetation. However this supply in its various forms was limited, weak and intermittent. The Industrial Revolution replaced these with fossil fuels and steam power bringing a great leap forward in the human condition and the size of population supportable on the Earth. However the IPCC is now telling us that that is not true, the consumption of carbon fuels in any form – coal, oil, gas, vegetation – is not sustainable for the population and lifestyle we expect today.

What are the options? We may join Donald Trump in dismissing the science that the IPCC shows us, but few are ready to do that.

More popular is the alternative of going back to the use of exclusively pre-industrial sources of energy, now called Renewables. It is true that their energy can now be harvested by modern means over vast areas, but the sources are weak as they always were. To replace a large fossil fuel power station requires hundreds of huge windmills over several square miles or a similar area closely plastered with solar panels.

Alternatively large rivers can be dammed generating ecological scars and displacing communities on a grand scale. Much damage has already been done on the Nile, Yangtze, Tigris and Mekong, but the number of suitable rivers is limited and water is itself a precious resource. These Renewables damage the environment and can hardly be described as Green!

But even more serious is the oft-described intermittency of Renewables: they cannot provide energy, anytime and anywhere, as a modern economy needs. Some opinion relies on the Micawber Principle, that in the end “something will turn up”, but there are clear scientific limits, for instance from the Periodic Table of the chemical elements on (to) prospects for battery technology.

But science already offers another source, first revealed by Henri Becquerel and Marie Curie, and fully studied for over a century. Nuclear energy is accepted by some but feared by many.

Compared with coal nuclear power provides nearly a million times the energy per kilogram of fuel, any time and almost anywhere. Plants are robust and compact, requiring as little as 15 hectares for one gigawatt output. And what about their safety and impact on the environment? “Look what happened at Chernobyl” is a frequently voiced reaction.

The accident in April 1986 devastated a large region in Ukraine that had to be evacuated – but did it? Wildlife pictures recorded there in recent years report that animals living in the region are thriving, radioactive but better off now without human interference than they were before. The animals must know something that we do not. “But they know nothing” Doctor Watson might say to this. “Quite so” Sherlock Holmes might reply, “but we may know something that isn't so.”

The evacuees at Chernobyl were terrified when told that they had been irradiated and should leave their homes immediately. This unseen and unexplained condemnation caused severe mental illness and social damage, but only 43 deaths can be linked to the radiation itself – 28 workers and 15 thyroid deaths in the wider population. The thousands of deaths and the waste land expected by most commentators never happened.

The truth was reported by IAEA and WHO in 2006, though stopping short of concluding that the health effects of radiation are significantly over-stated. As a result the human tragedy was repeated at Fukushima in 2011. Although there were no casualties from the radiation, the unnecessary evacuation and the fear, as devastating as a mediaeval curse, caused much human suffering.

Expensive economic and technical steps were taken around the world following the accident. But the message from the animals at Chernobyl shows that those steps were unnecessary.

I have spent many years understanding how life is affected by radiation and how we have come to fear it. Nuclear energy is very powerful, even compared with chemical energy. Both are parts of nature and can be abused to make weapons. A nuclear explosion may cause local destruction and fire, but the release of radiation is not the threat that the Cold War encouraged everybody to believe. Anyway nuclear energy plants cannot explode like bombs and the tiny quantity of waste they produce has never caused a fatality in 60 years.

Why is radiation so relatively harmless? From its beginnings 3,500 million years ago life had to evolve fool-proof ways to survive natural radiation and other oxidative agents, particularly with an immune system to suppress cancerous growth. Civilisation has no such immunity from Climate Change. Its survival will depend on gaining widespread acceptance of nuclear power in society through changes to education and public health, similar to when it domesticated fire all those millennia ago.

An informed society would set a simple safety threshold for low and moderate radiation dose rates. That would halve the time and effort to provide nuclear power from smaller local plants that also offered desalination, hydrogen production and district heating. In this way financial and regulatory obstacles should be dramatically reduced with popular understanding.

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作者簡介:牛津大學實驗粒子物理學榮休教授,鑽研電磁輻射、粒子、核子及醫學物理學多年,曾出版《正確的輻射觀 (Radiation and Reason: the Impact of Science on a Culture of Fear)》及《Nuclear is for Life: A Cultural Revolution》;《正確的輻射觀》已被翻譯成中文,在台灣出版發售。

This article was originally published at Radiation and Reason.

翻譯/Edward Ho 、Alan Chiu,另鳴謝張一中先生協助校對修改

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