為什么氣候變化對窮國影響比較大？

Right, as the world goes, is only in question between equals in power, while the strong do what they can and the weak suffer what they must.” This sentence from the History of the Peloponnesian War by Thucydides is the philosophy of Donald Trump’s administration. Thus, two of his advisers, HR McMaster and Gary Cohn, wrote in May that: “The world is not a ‘global community’ but an arena where nations, non-governmental actors and businesses engage and compete for advantage.” This amoral perspective has serious implications. In no area are global spillovers more significant and co-operation more vital than climate. The failure to act ensures that the poor would indeed suffer.

“當今世界通行的規(guī)則是，正義的基礎(chǔ)是雙方實力對等;同時我們也知道，強者可以做他們能夠做的一切，而弱者只能忍受他們必須忍受的一切。”修昔底德(Thucydides)所著的《伯羅奔尼撒戰(zhàn)爭史》(History of the Peloponnesian War)中的這句話，可以說是唐納德•特朗普(Donald Trump)政府的哲學。因此，他的兩名顧問，赫伯特•雷蒙德•麥克馬斯特(HR McMaster)和加里•科恩(Gary Cohn)，曾在5月寫道：“當今世界不是一個‘全球社會’，而是各個國家、非政府行為體和企業(yè)打交道并爭奪優(yōu)勢的競技場。”這個視角把道德拋在一邊，具有嚴重的潛在影響。而在所有領(lǐng)域里，氣候領(lǐng)域的全球溢出效應(yīng)是最顯著的，該領(lǐng)域的合作也是最關(guān)鍵的。未能采取行動意味著窮國將深受其害。

This is the conclusion of a chapter on the economic impact of weather shocks, in the International Monetary Fund’s latest World Economic Outlook. The largest negative impacts of the shocks being made more frequent by global warming are on tropical countries. Nearly all low-income countries are tropical. Yet these countries are the least able to protect themselves. Thus they are innocent victims of changes for which they bear no responsibility.

這是國際貨幣基金組織(IMF)最新發(fā)布的《世界經(jīng)濟展望》(World Economic Outlook)中有關(guān)天氣沖擊的經(jīng)濟影響一章的結(jié)論。全球變暖引發(fā)了更高頻度的沖擊，受到最大負面影響的是熱帶國家。幾乎所有低收入國家都在熱帶，這些國家的自我保護能力也是最低的，于是它們成了自身沒有任何責任的變化的無辜受害者。

In assessing these risks, one has to start from the proposition that anthropogenic global warming is a reality. The intellectual industry devoted to denying this is well-funded and noisy. But its arguments are highly unconvincing. The underlying physics are undeniable. Furthermore, the empirical connection between rising concentrations of greenhouse gases and temperature is unambiguous. If little or no action is taken, average temperatures could rise by 4°C, or more, above pre-industrial levels by the end of the century. Aware of the lengthy lead times needed if effective action is to be taken, both to mitigate climate change and adapt to it (where inescapable), rational people would act now.

人們在評估這些風險時，必須從這樣一個命題出發(fā)：人為全球變暖是一個事實。致力于否認這一點的知識產(chǎn)業(yè)不但資金充足，且聲勢浩大。但其論據(jù)極其缺乏說服力。人為全球變暖的物理機制是不可否認的。此外，溫室氣體濃度上升和氣溫上升之間存在明確的實證聯(lián)系。若不采取或僅采取少量行動，到本世紀末平均氣溫可能會比工業(yè)化之前水平高出4攝氏度，甚至更多。深知即使采取有效行動后還需要漫長時間——無論是緩解氣候變化還是(在氣候變化不可避免的情況下)適應(yīng)它——才能看到效果，理性的人現(xiàn)在就會采取行動。

The main obstacles to such action are three. First, specific economic interests, notably in the fossil fuel industry, are understandably opposed to action and, not infrequently, to the science that suggests it is necessary. Second, free-marketeers, who despise both governments and environmentalists, reject the science, because of its (to them) detestable policy implications. Third, few wish to inconvenience themselves, let alone threaten their standard of living, for the sake of the future, or people in poorer countries.

氣候行動主要有三大障礙。首先，可想而知一些特定經(jīng)濟利益——尤其是化石燃料行業(yè)——是反對氣候行動的，且往往反對提出氣候行動有必要的科學。其次，既鄙視政府又鄙視環(huán)保人士的自由市場論者不接受科學家的結(jié)論，原因是其可憎的政策影響(對他們而言)。第三，沒多少人愿意為了未來或貧窮國家的人民而給自己添麻煩，更不用說危及自己的生活水平。

So what is the evidence of the impact on the poorest of failure to act? The IMF authors start from our knowledge that higher temperatures make a range of weather-related disasters more likely because there will be more energy in the weather system. Such effects will include a greater frequency of — and greater damage done by — cyclones, floods, heatwaves and wildfires.

那么有什么證據(jù)能表明，不采取氣候行動會對貧窮國家造成沖擊呢?IMF的作者們從我們已經(jīng)掌握的知識出發(fā)，即氣溫升高會增加一系列天氣災(zāi)害的可能性，因為天氣系統(tǒng)里將積蓄更多能量。后果將包括更高頻度且破壞力更大的颶風、洪水、熱浪和野火。

Furthermore, the increased frequency of extreme events will also do relatively more damage to the poorest countries. This is so for two reasons: these countries are located in the regions of the world most likely to be adversely affected; and they are least able to protect themselves against, or manage, the impact. For the median low-income developing country, with an average temperature of 25°C, the effect of a 1°C increase in temperature is to lower that year’s growth by 1.2 percentage points.

此外，極端天氣災(zāi)害頻發(fā)對貧窮國家的損害也相對較大。這緣于兩個原因：這些國家位于全球最可能受到不利影響的地區(qū);而且它們抵御或應(yīng)對災(zāi)害沖擊的能力也是最差的。對于典型的低收入發(fā)展中國家，若平均氣溫為25攝氏度，那么氣溫每升高1攝氏度就會導(dǎo)致當年經(jīng)濟增長下降1.2個百分點。

Moreover, the impact is long-lasting. These costs come from the adverse effects of heat on productivity, agricultural output, health and even conflict. Extreme heat is costly. Adaptation to extreme weather remains very hard for poor countries. We have witnessed this autumn the far more damaging impact of huge storms on poorer countries, such as those in the Caribbean, than on the much wealthier US.

而且天氣災(zāi)害的影響是持久的。其代價來自高溫對生產(chǎn)率、農(nóng)業(yè)產(chǎn)出、健康甚至沖突的不利影響。極端高溫的損害尤其大。貧窮國家仍然很難適應(yīng)極端天氣。今年秋天，我們見證了大風暴對較貧窮的國家——如加勒比地區(qū)國家——造成的破壞遠遠超過對富得多的美國的破壞。

It is possible for well-managed nations to reduce these adverse impacts. Countries with superior infrastructure, better-regulated capital markets, flexible exchange rates and more accountable and democratic institutions recover faster economically from the adverse impact of temperature shocks than others. Hot regions in high-income countries also cope better than those in poorer ones. All this supports the view that the poorest countries are likely to be the most damaged by rising temperatures. The populations of such countries are more vulnerable because they are closer to subsistence.

管理有方的國家是可以減少這些不利影響的。對于那些基礎(chǔ)設(shè)施優(yōu)越、資本市場規(guī)范、匯率有彈性且機構(gòu)比較負責和民主的國家，其經(jīng)濟從氣溫沖擊的不利影響中恢復(fù)過來的速度要快于其他國家。炎熱地區(qū)高收入國家的應(yīng)對能力也比窮國更好。這一切都支持一個觀點：最貧窮的國家可能受到氣溫上升的最嚴重傷害。這些國家的百姓更脆弱，因為他們更接近貧困線。

With the temperature increases projected by 2100 under unmitigated climate change, annual real incomes per head of a representative low-income country would be 9 per cent lower than they would otherwise be. This would impose large costs on their vulnerable groups. Moreover, such a forecast ignores the risks and uncertainties around any such estimates. A planet 4°C warmer than the pre-industrial average would be so different from the one we are now used to that the implications are in significant part unknowable.

根據(jù)未受緩解的氣候變化下到2100年的升溫預(yù)測，典型低收入國家的人均實際收入將比原本應(yīng)有水平低9%，這將給其弱勢群體帶來巨大損失。而且，該預(yù)測還沒有考慮圍繞此類估測的風險和不確定性。一個氣溫比工業(yè)化之前平均水平高出4攝氏度的地球，將與我們習以為常的地球如此不同，以至于有很大一部分影響是不可知的。

The IMF’s analysis has a number of serious implications. First and most important, low-income countries need to develop quickly to be better able to cope with weather shocks. Second, their development needs to be consistent with mitigating the rise in global temperatures. Third, we need rapid improvements in the relevant technologies and their swift dissemination. Fourth, we also need to help poor countries adapt to the changes in climate already sure to happen. Fifth, we need to develop insurance against weather-related shocks to poor countries. Finally, a moral case also exists for compensating losers from the costs of the unmitigated climate changes being imposed by richer countries.

IMF的分析有一些重要含意。首先最重要的是，低收入國家需要迅速發(fā)展，以更好地應(yīng)對天氣沖擊。第二，它們的發(fā)展需要與緩解全球氣溫上升的目標一致。第三，我們需要快速改進相關(guān)科技，并加快它們的普及。第四，我們還需要幫助窮國適應(yīng)已經(jīng)肯定會發(fā)生的氣候變化。第五，我們需要開發(fā)保險以保護窮國免受天氣相關(guān)災(zāi)害沖擊。最后還有一個道德方面的考量，要補償那些因富國造成的未受緩解的氣候變化而付出代價的輸家。

We should not let the urgent stop us from thinking about the important. The linked challenges of climate and development will shape humanity’s future.

我們不應(yīng)該讓緊急的事阻止自己去思考重要的事。相互關(guān)聯(lián)的氣候與發(fā)展挑戰(zhàn)將塑造人類的未來。