A部分

Palm oil is an edible oil derived from the fruit of the African oil palm tree, and is currently the most consumed vegetable oil in the world. It’s almost certainly in the soap we wash with in the morning, the sandwich we have for lunch, and the biscuits we snack on during the day. Why is palm oil so attractive for manufacturers? Primarily because its unique properties – such as remaining solid at room temperature – make it an ideal ingredient for long-term preservation, allowing many packaged foods on supermarket shelves to have ‘best before’ dates of months, even years, into the future.

B部分

Many farmers have seized the opportunity to maximise the planting of oil palm trees. Between 1990 and 2012, the global land area devoted to growing oil palm trees grew from 6 to 17 million hectares, now accounting for around ten percent of total cropland in the entire world. From a mere two million tonnes of palm oil being produced annually globally 50 years ago, there are now around 60 million tonnes produced every single year, a figure looking likely to double or even triple by the middle of the century.

C部分

However, there are multiple reasons why conservationists cite the rapid spread of oil palm plantations as a major concern. There are countless news stories of deforestation, habitat destruction and dwindling species populations, all as a direct result of land clearing to establish oil palm tree monoculture on an industrial scale, particularly in Malaysia and Indonesia. Endangered species – most famously the Sumatran orangutan, but also rhinos, elephants, tigers, and numerous other fauna – have suffered from the unstoppable spread of oil palm plantations.

D部分

‘Palm oil is surely one of the greatest threats to global biodiversity,’ declares Dr Farnon Ellwood of the University of the West of England, Bristol. ‘Palm oil is replacing rainforest, and rainforest is where all the species are. That’s a problem.’ This has led to some radical questions among environmentalists, such as whether consumers should try to boycott palm oil entirely.

Meanwhile Bhavani Shankar, Professor at London’s School of Oriental and African Studies, argues, ‘It’s easy to say that palm oil is the enemy and we should be against it. It makes for a more dramatic story, and it’s very intuitive. But given the complexity of the argument, I think a much more nuanced story is closer to the truth.’

E部分

One response to the boycott movement has been the argument for the vital role palm oil plays in lifting many millions of people in the developing world out of poverty. Is it desirable to have palm oil boycotted, replaced, eliminated from the global supply chain, given how many low-income people in developing countries depend on it for their livelihoods? How best to strike a utilitarian balance between these competing factors has become a serious bone of contention.

F部分

Even the deforestation argument isn’t as straightforward as it seems. Oil palm plantations produce at least four and potentially up to ten times more oil per hectare than soybean, rapeseed, sunflower or other competing oils. That immensely high yield – which is predominantly what makes it so profitable – is potentially also an ecological benefit. If ten times more palm oil can be produced from a patch of land than any competing oil, then ten times more land would need to be cleared in order to produce the same volume of oil from that competitor.

As for the question of carbon emissions, the issue really depends on what oil palm trees are replacing. Crops vary in the degree to which they sequester carbon – in other words, the amount of carbon they capture from the atmosphere and store within the plant. The more carbon a plant sequesters, the more it reduces the effect of climate change. As Shankar explains: ‘[Palm oil production] actually sequesters more carbon in some ways than other alternatives. […] Of course, if you’re cutting down virgin forest it’s terrible – that’s what’s happening in Indonesia and Malaysia, it’s been allowed to get out of hand. But if it’s replacing rice, for example, it might actually sequester more carbon.’

G部分

The industry is now regulated by a group called the Roundtable on Sustainable Palm Oil (RSPO), consisting of palm growers, retailers, product manufacturers, and other interested parties. Over the past decade or so, an agreement has gradually been reached regarding standards that producers of palm oil have to meet in order for their product to be regarded as officially ‘sustainable’. The RSPO insists upon no virgin forest clearing, transparency and regular assessment of carbon stocks, among other criteria. Only once these requirements are fully satisfied is the oil allowed to be sold as certified sustainable palm oil (CSPO). Recent figures show that the RSPO now certifies around 12 million tonnes of palm oil annually, equivalent to roughly 21 percent of the world’s total palm oil production.

H部分

There is even hope that oil palm plantations might not need to be such sterile monocultures, or ‘green deserts’, as Ellwood describes them. New research at Ellwood’s lab hints at one plant which might make all the difference. The bird’s nest fern  grows on trees in an epiphytic fashion (meaning it’s dependent on the tree only for support, not for nutrients), and is native to many tropical regions, where as a keystone species it performs a vital ecological role. Ellwood believes that reintroducing the bird’s nest fern into oil palm plantations could potentially allow these areas to recover their biodiversity, providing a home for all manner of species, from fungi and bacteria, to invertebrates such as insects, amphibians, reptiles and even mammals.

A部分
棕榈油是从非洲棕榈树果实中提取的食用油，目前是全球消费量最大的植物油。它几乎肯定存在于我们早上用来洗手的肥皂、中午吃的三明治和白天吃的饼干中。为什么棕榈油对制造商如此有吸引力？主要是因为它独特的特性，比如在室温下保持固态，使其成为长期保存的理想成分，使得许多超市货架上的包装食品可以在未来数月甚至数年内拥有“最佳食用日期”。

B部分
许多农民抓住机会最大程度地种植油棕树。从1990年到2012年，全球种植油棕树的土地面积从600万公顷增长到1700万公顷，现占全球耕地总面积的约10%。50年前，全球年产棕榈油仅为200万吨，现在每年产量约为6000万吨，预计到本世纪中叶这个数字可能会翻倍甚至翻三倍。

C部分
然而，保护主义者们列举了多个原因，认为棕榈油植园的迅速扩张是一个重大问题。有无数新闻报道称，由于为了建立工业规模的油棕树单一种植园而进行的土地清理，导致森林砍伐、栖息地破坏和物种数量减少。濒危物种，尤其是苏门答腊猩猩，以及犀牛、大象、老虎和其他许多动物，都因油棕植园的不可阻挡的扩张而受到了影响。

D部分
英国西英格兰大学布里斯托尔分校的法诺恩·埃尔伍德博士宣称：“棕榈油无疑是全球生物多样性面临的最大威胁之一。棕榈油正在取代热带雨林，而热带雨林是物种的栖息地。这是一个问题。”这引发了环保主义者们一些激进的问题，比如消费者是否应该尝试完全抵制棕榈油。

与此同时，伦敦东方与非洲研究学院的教授巴瓦尼·尚卡尔认为：“说棕榈油是敌人，我们应该反对它，这样会更有戏剧性，更直观。但考虑到问题的复杂性，我认为更接近真相的是一个更细致入微的故事。”

E部分
抵制运动的一个回应是，棕榈油在帮助数百万发展中国家的低收入人口摆脱贫困方面发挥了重要作用。鉴于多少发展中国家的低收入人口依赖棕榈油谋生，抵制、替代或从全球供应链中消除棕榈油是否可取？如何在这些竞争因素之间取得最佳效益成为一个严重的争议点。

F部分
即使是森林砍伐的论点也没有看起来那么简单。与大豆、油菜籽、葵花籽或其他竞争油相比，油棕植园每公顷至少可以生产四倍甚至十倍的油。这种极高的产量（主要是使其如此有利可图的原因）也可能是生态效益。如果用于竞争对手相同数量的油，就需要清理十倍的土地。

至于碳排放问题，实际情况取决于油棕树取代的是什么作物。作物在固定碳的程度上有所不同，也就是从大气中吸收的碳量和储存在植物内部的碳量。植物固定的碳越多，就越能减少气候变化的影响。正如尚卡尔所解释的：“（棕榈油生产）实际上在某些方面比其他替代品固定更多的碳。……当然，如果你砍伐原始森林，那是可怕的，印度尼西亚和马来西亚正在发生的就是这种情况，情况已经失控。但如果它取代的是稻米，它可能实际上固定了更多的碳。”

G部分
该行业现在由一个名为可持续棕榈油圆桌会议（RSPO）的组织进行监管，该组织由棕榈种植者、零售商、产品制造商和其他相关方组成。在过去的十年左右的时间里，关于棕榈油生产者必须满足的标准逐渐达成了一致，以便让他们的产品被视为正式的“可持续”产品。RSPO坚持不进行原始森林砍伐，要求透明度和定期评估碳储量，以及其他标准。只有在完全满足这些要求之后，油才能被销售为经认证的可持续棕榈油（CSPO）。最近的数据显示，RSPO现在每年认证约1200万吨棕榈油，相当于全球棕榈油总产量的约21%。

H部分
甚至有希望油棕植园不再成为如埃尔伍德所形容的“绿色沙漠”或单一种植园。埃尔伍德实验室的新研究暗示可能会有一种植物可以改变一切。鸟巢蕨以附生的方式生长在树上（意味着它只依赖于树木提供支持，而不依赖于养分），并且是许多热带地区的特有种，作为关键物种它发挥着重要的生态作用。埃尔伍德认为，重新引入鸟巢蕨到油棕植园可能使这些地区恢复生物多样性，为各种物种提供家园，包括真菌、细菌、无脊椎动物如昆虫、两栖动物、爬行动物甚至哺乳动物。