GREEN BONDS are the stars of climate finance. These instruments, which channel funds raised towards environmentally friendly projects, raised $271bn in 2019, according to BloombergNEF, a consultancy. That is only about 4% of total bond issuance worldwide, but it easily makes green bonds the most popular form of eco-friendly debt. Covid-19 has only slightly slowed the rise. On September 2nd Germany issued green paper for the first time. The European Commission is mulling using them to fund just under a third of its ?50bn ($888bn) stimulus package.
绿色债券是气候融资的明星。咨询公司BloombergNEF的数据显示，这些融资工具作为融资渠道，将筹集的资金用于绿色环保项目，并在在2019年筹集了2710亿美元。这个数额虽然只占全球债券发行总量的4%左右，却让绿色债券轻而易举地成为最受欢迎的环保债券。新冠疫情只是略微减缓了绿色债券的增长速度。9月2日，德国首次发由绿皮书。欧盟委员会正考虑利用绿色债券为7500亿欧元经济刺激计划提供近三分之一的资金。
Yet a new study by the Bank for International Settlements, a club of central banks, raises questions about the purpose of green bonds. Researchers looked at 200-odd large firms that issued them in 2015-18. They found that firms that issue the most tend to be cleaner in the first place—ie, they produce the least carbon for a given amount of revenue. Over 70% of issuers have a carbon intensity equivalent to a consumer-staples firm, such as Procter & Gamble, or lower. Large polluters rarely issue such bonds for fear of being accused of greenwashing, and because the bonds would be excluded from green funds.然而，由各国中央银行组成的国际清算银行的一项新研究对绿色债券的目的提出了疑问。研究人员调查了2015年至2018年发行绿色债券的200多家大型企业，发现，绿色债券发行量最多的企业往往是最为节能的，也就是说，在一定的收入水平下，他们排放的碳数量最少。超过70%的债券发行企业的碳排放强度相当于日用消费品企业(如宝洁)，甚至还更少。大型污染企业很少发行此类债券，因为它们担心被指责为“洗绿”，同时这些企业的债券将被排除在绿色基金之外。
Another finding was that green-bond issuance did not seem to lead to decarbonisation. In the years after issuance, the average carbon intensity oscillates wildly, but the changes are not statistically significant. Moreover, though some issuers claim that tapping the green-bond market lowers their cost of borrowing, data from the IMF suggest a discount is rare (see chart).另一发现是绿色债券的发行似乎不会必 然实现去碳化。在绿色债券发行后的几年里，平均碳浓度波动剧烈，但统计的碳排放变化并不显著。此外，尽管一些债券发行企业声称开发绿色债券市场降低了他们的借贷成本，但来自国际货币基金组织的数据显示发行价的减少情况几乎没有(见图表)。
If green bonds cut neither costs nor carbon directly, then what are they for? Proponents still see benefits. Some green bonds fund worthy projects that do not reduce carbon footprints, such as improving water management. This is the case for at least a fifth of the stock of green bonds by value, reckons HSBC, a bank. Moreover, many bonds are used to refinance genuinely green projects. So the reduction in carbon dioxide may have happened before issuance, argues Sean Kidney of the Climate Bond Initiative, a non-profit group.如果绿色债券既不直接削减成本，也不直接削减碳排放量，那么它们还有什么用呢?支持者仍然看到了好处。一些绿色债券资助那些虽然不减少碳足迹却很有价值的项目，如改善水资源管理的项目。据汇丰银行估计，至少有五分之一的绿色债券处于这种状况。此外，许多绿色债券用于给真正的绿色项目再融资。非营利组织“气候债券倡议”的Sean Kidney认为，在绿色债券发行之前，二氧化碳的就可能在减少了。
For issuers, one advantage is reputational. Issuing a green bond sends virtuous signals to regulators. Chris Kaminker of Lombard Odier, a bank, argues that the green label may also attract a wider pool of lenders than conventional bonds.对发行者来说，一个优势是声誉。发行绿色债券会向监管机构发出良性信号。Lombard Odier银行的Chris Kaminker认为，与传统债券相比，绿色标签可能会吸引更广泛的贷款机构。
Green bonds can also make life easier for institutional investors pressed by clients to become more climate-conscious. They could invest directly in green projects, which often take the form of infrastructure. But a failed project may default on its repayments to direct investors. Green-bondholders face less risk; the issuer must pay even if the project fails. Issuers also typically disclose the details of projects, such as their size and location. Such morsels are otherwise hard to come by.绿色债券还可以让机构投资者的日子好过一些，因为他们受到客户的压力，要求他们更加注重气候变化。他们可以直接投资于绿色项目，而这些项目通常是在基础设施领域。不过，一个失败的项目可能造成对直接投资者的还款爆雷。绿色债券持有者面临的风险较小;即使投资的项目失败了，发行企业也必须还款。发行企业通常还会披露项目的细节，比如规模和地点。除此之外，这些绿色债券很难买到。
Investors seeking to encourage decarbonisation could turn to newer instruments. Big polluters can use the proceeds of “transition” bonds to decarbonise. In March Cadent Gas, a British firm, raised a ?00m note to reduce leakages from its pipeline, among other things. “Sustainability-linked” bonds tie interest payments to the achievement of a target. The first of these was issued by Enel, an Italian electricity firm, last year, and is linked to increasing the share of renewables in its generation capacity.寻求鼓励去碳化的投资者可能会转向更新的投资工具。污染大户可以将“转型”债券的收益用于去碳化。例如，今年三月，英国Cadent Gas筹集了5亿欧元资金以减少管道泄漏事故。“与可持续发展挂钩”的债券将利息支付与目标的实现挂钩。去年，意大利电力公司Enel发布了第 一个计划，旨在提高可再生能源在其发电能力中的份额。
So far there have only been a handful of issuances of these newer sorts of bonds. Expanding the market will take time, as investors become familiar with them. For now, climate-conscious investors may have to stick with green bonds—and doing less good for the planet than they may have claimed to their clients.到目前为止，这些最 新型的债券发行数量还不多。扩大市场将需要时间，投资者在逐渐熟悉它们。目前，有气候意识的投资者可能得坚持支持绿色债券——而他们对地球的贡献可能没有对客户宣扬的那么大。
