富國須爲清潔能源做好表率

As the UN conference on sustainable development begins it is the Rich countries that have the most to prove. The last summit in Rio de Janeiro 20 years ago provided the opportunity for countries to sign the UN framework convention on climate change, which should have stabilised global annual emissions of greenhouse gases at 1990 levels, and placed prime responsibility on the industrialised nations, who have done most to pollute the atmosphere, to lead by example.

在聯合國可持續發展大會(UN conference on sustainable development)於里約熱內盧召開之際，最有必要證明自己的是富裕國家。上一次里約峯會是20年前召開的。那次峯會爲各國簽署《聯合國氣候變化框架公約》(UN framework convention on climate change)提供了機會。該公約的目標是把全球溫室氣體年排放量穩定在1990年的水平，並讓工業化國家承擔起主要責任（因爲它們給大氣造成的累計污染最多），爲其他國家作出表率。

But rich countries have not led and annual global emissions have continued to rise. Even taking into account pledges by rich and poor nations for action by 2020, the world appears to be heading for likely global warming of 3°C or more, to a temperature not seen on earth for about 3m years.

但富裕國家卻未能起到表率作用，全球溫室氣體年排放量仍在持續上升。即便把富國和窮國承諾在2020年前實施相應行動這一因素考慮在內，全球氣溫似乎也難以避免會上升3攝氏度或更多，達到約300萬年來地球上未曾出現過的水平。

Having witnessed, for instance, failure by the US and Canada to honour their signatures to the Kyoto protocol, as we approach another summit, poor countries are understandably sceptical of the lofty ambitions expressed by rich nations.

窮國注意到了富國的所作所爲，比如美國和加拿大都未能恪守簽署《京都議定書》(Kyoto protocol)的承諾。因此，在我們召開又一次峯會之際，窮國對富國表述的宏偉抱負感到懷疑，是可以理解的。

It will take more than words to restore the confidence of poor countries. Some richer ones are dragging their feet on tackling climate change, while unfairly criticising the developing world, apparently unaware of the strides that these countries are making in finding a new path. China, India, Mexico, Brazil and other emerging powers have laid out ambitious plans to tackle deforestation and to reduce radically their emissions to output ratios. More importantly, they are implementing those plans.

若想使窮國恢復對減排事業的信心，顯然不能光動嘴。一些富國在應對氣候變化方面行動遲緩，同時還對發展中國家進行了不公正的批評。它們無疑沒有意識到發展中國家在尋找解決氣候變化問題的新途徑上取得了多大的進展。中國、印度、墨西哥、巴西以及其他新興國家，制定了對付濫砍濫伐和大幅降低排放產出比的宏偉計劃。更重要的是，它們正在貫徹這些計劃。

One of the biggest injustices of climate change is that the poorest countries are most exposed and vulnerable to the impacts of climate change even though they have done least to raise atmospheric levels of greenhouse gases. Now they must contend with the brutal arithmetic of a tight budget for global emissions as they try to fight poverty, develop and grow, while managing the enormous risks of climate change.

氣候變化問題中最不公平的一點是，最貧窮國家面臨的威脅最大，也最容易受到氣候變化的影響，儘管它們在導致大氣中溫室氣體含量升高一事上責任最小。現在，它們必須面對嚴厲的全球排放預算給出的苛刻目標，同時還要努力解決貧窮、發展和增長問題，並管控氣候變化帶來的巨大風險。

Rich and poor countries agreed in Cancún in December 2010 that global emissions should be reduced to avoid a rise in global average temperatures of more than 2°C. To have a reasonable chance of this, global average emissions have to be reduced from the present level of about 7 tonnes per capita of carbon-dioxide-equivalent to about 2 tonnes in 2050.

2010年12月，富國和窮國在坎昆一致同意，全球減排的目標應該是避免全球平均氣溫上升2攝氏度以上。如果想實現這一目標，那麼到2050年時，全球平均排放水平必須從當前的人均約7噸二氧化碳當量降到人均2噸左右。

This is a huge challenge as developing countries will be home to 8bn of the projected global population in 2050 of 9bn. Even if the rich countries reduce their emissions to zero by 2030, developing nations would need to hold their emissions to about 5 tonnes per capita by 2030 and 2.5 tonnes by 2050. For comparison, current per capita emissions are 22 tonnes in the US, over 9 tonnes in the EU, about 7 tonnes in China, and 2 tonnes in India.

這是一個巨大的挑戰，因爲到2050年時全球人口預計將達到90億，而發展中國家的人口將達到80億。即便富國到2030年時實現零排放，發展中國家也仍需大幅降低排放水平——到2030年時降到人均5噸左右，到2050年時降到人均2.5噸。作爲比較，目前美國的人均排放量是22噸，歐盟超過9噸，中國約爲7噸，印度爲2噸。

So rich countries not only have to accelerate their actions, but must also support the poor countries as they make the transition to low-carbon economic growth.

因此，富國不僅需要加快自身的行動，還必須支持窮國轉向低碳型經濟增長。

It would be morally unacceptable to try to insist that developing countries drop or scale back plans to fight poverty and raise material standards of living. The developing world is understandably suspicious that this is a hidden agenda. Yet it is a fact that their growth is the biggest source of the rise of emissions. The answer is clear: radical change in emissions per unit of output. This revolution carries many benefits: cleaner, quieter, safer, more energy-secure, and more biologically diverse energy. Rich countries must support this with technology and resources.

有些人堅決要求發展中國家放棄或縮減對抗貧困和提高物質生活水平的計劃，這在道德上是無法令人接受的。發展中國家懷疑這種言論背後有不可告人的目的，也在情理之中。但同樣不可否認的是，發展中國家的經濟增長是溫室氣體排放量上升的最大源泉。解決辦法很明確：徹底降低每單位產出排放量。這種革命會帶來許多益處：能源會變得更清潔、更安靜、更安全、供應更有保障，生物能源的種類也會變得更多。富國必須爲這種革命提供技術和資源上的支持。

The developed world must not attempt to preach to poorer nations. As they deal with the largely self-inflicted damage to their economies, rich countries must show they understand the dangers that arise from hesitation in acting against climate change. They will discover by investing in the low-carbon economy, adopting clear and credible policies, and building new technologies and markets, they will help to create the only truly sustainable growth path for the future, and help find a way out of the depression of their own making.

發達國家不要試圖對較貧窮國家進行說教。富國在應對自身的經濟困境（這種困境在很大程度上是由它們自己造成的）之際，必須向外界表明，它們清楚在應對氣候變化問題上猶豫不決帶來的風險。通過投資低碳型經濟、出臺明確而可信的政策和開發新技術和市場，富國會發現，它們能夠幫助開闢通向未來的唯一真正可持續增長之路，能夠找到辦法走出自己釀成的經濟蕭條。

Nicholas Stern is I.G. Patel Professor of Economics and Government and chair of the Grantham Research Institute at the London School of Economics. Jose Antonio Ocampo is a Professor at Columbia University and former Minister of Finance in Colombia

尼古拉斯•斯特恩(Nicholas Stern)是倫敦政治經濟學院(LSE) IG帕特爾經濟與政府學教授(I.G. Patel Professor of Economics and Government)、格蘭瑟姆研究所(Grantham Research Institute)所長；何塞•安東尼奧•奧坎波(José Antonio Ocampo)是哥倫比亞大學(Columbia University)教授，曾任哥倫比亞財政部長