The history of tea
The story of tea begins in China. According to legend, in 2737 BC, the Chinese emperor Shen
Nung was sitting beneath a tree while his servant boiled drinking water, when some leaves
from the tree blew into the water. Shen Nung, a renowned herbalist, decided to try the
infusion that his servant had accidentally created. The tree was a Camellia sinensis, and the
resulting drink was what we now call tea. It is impossible to know whether there is any truth
in this story. But tea drinking certainly became established in China many centuries before it
had even been heard of in the West. Containers for tea have been found in tombs dating from
the Han Dynasty (206 BC—220 AD) but it was under the Tang Dynasty (618—906 AD), that
tea became firmly established as the national drink of China.
It became such a favourite that during the late eighth century a writer called Lu Yu wrote the
first book entirely about tea, the Ch’a Ching, or Tea Classic. It was shortly after this that tea
was first introduced to Japan, by Japanese Buddhist monks who had travelled to China to
study. Tea received almost instant imperial sponsorship and spread rapidly from the royal
court and monasteries to the other sections of Japanese society.
So at this stage in the history of tea, Europe was rather lagging behind. In the latter half of the
sixteenth century there are the first brief mentions of tea as a drink among Europeans. These
are mostly from Portuguese who were living in the East as traders and missionaries. But
although some of these individuals may have brought back samples of tea to their native
country, it was not the Portuguese who were the first to ship back tea as a commercial import.
This was done by the Dutch, who in the last years of the sixteenth century began to encroach
on Portuguese trading routes in the East. By the turn of the century they had established a
trading post on the island of Java, and it was via Java that in 1606 the first consignment of tea
was shipped from China to Holland. Tea soon became a fashionable drink among the Dutch,
and from there spread to other countries in continental western Europe, but because of its
high price it remained a drink for the wealthy.
Britain, always a little suspicious of continental trends, had yet to become the nation of tea
drinkers that it is today. Starting in 1600, the British East India Company had a monopoly on
importing goods from outside Europe, and it is likely that sailors on these ships brought tea
home as gifts. The first coffee house had been established in London in 1652, and tea was
still somewhat unfamiliar to most readers, so it is fair to assume that the drink was still
something of a curiosity. Gradually, it became a popular drink in coffee houses, which were
as many locations for the transaction of business as they were for relaxation or pleasure. They
were though the preserve of middle- and upper-class men; women drank tea in their own
homes, and as yet tea was still too expensive to be widespread among the working classes. In
part, its high price was due to a punitive system of taxation.
One unforeseen consequence of the taxation of tea, particularly of smuggled tea to avoid
taxation—smuggling and adulteration. By the eighteenth century many Britons wanted to
drink tea but could not afford the high prices, and their enthusiasm for the drink was matched
by the enthusiasm of criminal gangs to smuggle it in. What began as a small time illegal
trade, selling a few pounds of tea to personal contacts, developed by the late eighteenth
century into an astonishing organised crime network, perhaps importing as much as 7 million
lbs annually, compared to a legal import of 5 million lbs! Worse for the drinkers was that
taxation also encouraged the adulteration of tea, particularly of smuggled tea which was not
quality controlled through customs and excise. Leaves from other plants, or leaves which had
already been brewed and then dried, were added to tea leaves. By 1784, the government
realised that enough was enough, and that heavy taxation was creating more problems than it
was words. The new Prime Minister, William Pitt the Younger, slashed the tax from 119 per
cent to 12.5 per cent. Suddenly legal tea was affordable, and smuggling stopped virtually
overnight.
Another great impetus to tea drinking resulted from the end of the East India Company’s
monopoly on trade with China, in 1834. Before that date, China was the country of origin of
the vast majority of the tea imported to Britain, but the end of its monopoly stimulated the
East India Company to consider growing tea outside China. India had always been the centre
of the Company’s operations, which led to the increased cultivation of tea in India, beginning
in Assam. There were a few false starts, including the destruction by cattle of one of the
earliest tea nurseries, but by 1888 British tea imports from India were for the first time
greater than those from China.
The end of the East India Company’s monopoly on trade with China also had another result,
which was more dramatic though less important in the long term: it ushered in the era of the
tea clippers. While the Company had had the monopoly on trade, there was no rush to bring
the tea from China to Britain, but after 1834 the tea trade became a virtual free for all.
Individual merchants and sea captains with their own ships raced to bring home the tea and
make the most money, using fast new clippers which had sleek lines, tall masts and huge
sails. In particular there was a competition between British and American merchants, leading
to the famous clipper races of the 1860s. But these races soon came to an end with the
opening of the Suez Canal, which made the trade routes to China viable for steamships for
the first time.
Biodiversity
A. It seems biodiversity has become a buzzword beloved of politicians, conservationists,
protesters and scientists alike. But what exactly is it? The Convention on Biological
Diversity, an international agreement to conserve and share the planet’s biological riches,
provides a good working definition: biodiversity comprises every form of life, from the
smallest microbe to the largest animal or plant, the genes that give them their specific
characteristics and the ecosystems of which they are apart.
B. In October, the World Conservation Union (also known as the IUCN) published its
updated Red List of Threatened Species, a roll call of 11,167 creatures facing extinction –
121 more than when the list was last published in 2000. But the new figures almost certainly
underestimate the crisis. Some 1.2 million species of animal and 270,000 species of plant
have been classified, but the well-being of only a fraction has been assessed. The resources
are simply not available. The IUCN reports that 5714 plants are threatened, for example, but
admits that only 4 per cent of known plants has been assessed. And, of course, there are
thousands of species that we have yet to discover. Many of these could also be facing
extinction.
C. It is important to develop a picture of the diversity of life on Earth now so that
comparisons can be made in the future and trends identified. But it isn’t necessary to observe
every single type of organism in an area to get a snapshot of the health of the ecosystem. In
many habitats, there are species that are particularly susceptible to shifting conditions, and
these can be used as indicator species.
D. In the media, it is usually large, charismatic animals such as pandas, elephants, tigers and
whales that get all the attention when a loss of biodiversity is discussed. However, animals or
plants far lower down the food chain are often the ones vital for preserving habitats – in the
process saving the skins of those more glamorous species. They are known as keystone
species.
E. By studying the complex feeding relationships within habitats, species can be identified
that have a particularly important impact on the environment. For example, the members of
the fig family are the staple food for hundreds of different species in many different
countries, so important that scientists sometimes call figs “jungle burgers”. A whole range of
animals, from tiny insects to birds and large mammals, feed on everything from the tree’s
bark and leaves to its flowers and fruits. Many fig species have very specific pollinators.
There are several dozen species of the fig tree in Costa Rica, and a different type of wasp has
evolved to pollinate each one. Chris Lyle of the Natural History Museum in London – who is
also involved in the Global Taxonomy Initiative of the Convention on Biological Diversity –
points out that if fig trees are affected by global warming, pollution, disease or any other
catastrophe, the loss of biodiversity will be enormous.
F. Similarly, sea otters play a major role in the survival of giant kelp forests along the coasts
of California and Alaska. These “marine rainforests” provide a home for a wide range of
other species. The kelp itself is the main food of purple and red sea urchins and in turn, the
urchins are eaten by predators, particularly sea otters. They detach an urchin from the seabed
then float to the surface and lie on their backs with the urchin shell on their tummy, smashing
it open with a stone before eating the contents. Urchins that are not eaten tend to spend their
time in rock crevices to avoid the predators. This allows the kelp to grow – and it can grow
many centimetres in a day. As the forests form, bits of kelp break off and fall to the bottom to
provide food for the urchins in their crevices. The sea otters thrive hunting for sea urchins in
the kelp, and many other fish and invertebrates live among the fronds. The problems start
when the sea otter population declines. As large predators they are vulnerable – their numbers
are relatively small to disease or human hunters can wipe them out. The result is that the sea
urchin population grows unchecked and they roam the seafloor eating young kelp fronds.
This tends to keep the kelp very short and stops forests developing, which has a huge impact
on biodiversity.
G. Conversely, keystone species can also make dangerous alien species: they can wreak
havoc if they end up in the wrong ecosystem. The cactus moths, whose caterpillar is a
voracious eater of prickly pear was introduced to Australia to control the rampant cacti. It was
so successful that someone thought it would be a good idea to introduce it to Caribbean
islands that had the same problem. It solved the cactus menace, but unfortunately, some of the
moths have now reached the US mainland – borne on winds and in tourists’ luggage – where
they are devastating the native cactus populations of Florida.
H. Organisations like the Convention on Biological Diversity work with groups such as the
UN and with governments and scientists to raise awareness and fund research. A number of
major international meetings – including the World Summit on Sustainable Development in
Johannesburg this year – have set targets for governments around the world to slow the loss
of biodiversity. And the CITES meeting in Santiago last month added several more names to
its list of endangered species for which trade is controlled. Of course, these agreements will
prove of limited value if some countries refuse to implement them.
I. There is cause for optimism, however. There seems to be a growing understanding of the
need for sustainable agriculture and sustainable tourism to conserve biodiversity. Problems
such as illegal logging are being tackled through sustainable forestry programmes, with the
emphasis on minimising the use of rainforest hardwoods in the developed world and on
rigorous replanting of whatever trees are harvested. CITES is playing its part by controlling
trade in wood from endangered tree species. In the same way, farming experts encourage
sustainable farming techniques that minimise environmental damage and avoid
monoculture."
J. Action at a national level often means investing in public education and awareness. Getting
people like you and me involved can be very effective. Australia and many European
countries are becoming increasingly efficient at recycling much of their domestic waste, for
example, preserving natural resources and reducing the use of fossil fuels. This, in turn, has a
direct effect on biodiversity by minimising pollution, and an indirect effect by reducing the
number of greenhouse gases emitted from incinerators and landfill sites. Preserving
ecosystems intact for future generations to enjoy is obviously important, but biodiversity is
not some kind of optional extra. Variety may be “the spice of life”, but biological variety is
also our life-support system.
Nature works Polylactic acid
A. dozen years ago, scientists at Cargill got the idea of converting lactic acid made from corn
into plastic while examining possible new uses for materials produced from corn wet milling
processes. In the past, several efforts had been made to develop plastics from lactic acid, but
with limited success. Achieving this technological breakthrough didn’t come easily, but in
time the efforts did succeed. A fermentation and distillation process using corn was designed
to create a polymer suitable for a broad variety of applications.
B. As an agricultural based firm, Cargill had taken this product as far as it could by 1997. The
company needed a partner with access to plastics markets and polymerization capabilities,
and began discussions with The Dow Chemical Company. The next step was the formation of
the joint venture that created Cargill Dow LLC. Cargill Dow’s product is the world’s first
commercially available plastic made from annually renewable resources such as corn:
• Nature Works™ PLA is a family of packaging polymers (carbon-based molecules)
made from non-petroleum based resources.
• Ingeo is a family of polymers for fibers made in a similar manner."
C. By applying their unique technology to the processing of natural plant sugars, Cargill Dow
has created a more environmentally friendly material that reaches the consumer in clothes,
cups, packaging and other products. While Cargill Dow is a stand-alone business, it continues
to leverage the agricultural processing, manufacturing and polymer expertise of the two
parent companies in order to bring the best possible products to market.
D. The basic raw materials for PLA are carbon dioxide and water. Growing plants, like corn,
take these building blocks from the atmosphere and the soil. They are combined in the plant
to make carbohydrates (sucrose and starch) through a process driven by photosynthesis. The
process for making Nature Works PLA begins when a renewable resource such as corn is
milled, separating starch from the raw material. Unrefined dextrose, in turn, is processed
from the starch.
E. Cargill Dow turns the unrefined dextrose into lactic acid using a fermentation process
similar to that used by beer and wine producers. This is the same lactic acid that is used as a
food additive and is found in muscle tissue in the human body. Through a special
condensation process, a lactide is formed. This lactide is purified through vacuum distillation
and becomes a polymer (the base for NatureWorks PLA) that is ready for use through a
solvent-free melt process. Development of this new technology allows the company to
“harvest” the carbon that living plants remove from the air through photosynthesis. Carbon is
stored in plant starches, which can be broken down into natural plant sugars. The carbon and
other elements in these natural sugars are then used to make NatureWorks PLA.
F. Nature Works PLA fits all disposal systems and is fully compostable in commercial
composting facilities. With the proper infrastructure, products made from this polymer can be
recycled back to a monomer and re-used as a polymer. Thus, at the end of its life cycle, a
product made from Nature Works PLA can be broken down into its simplest parts so that no
sign of it remains.
G. PLA is now actively competing with traditional materials in packaging and fiber
applications throughout the world; based on the technology’s success and promise, Cargill
Dow is quickly becoming a premier player in the polymers market. This new polymer now
competes head-on with petroleum-based materials like polyester. A wide range of products
that vary in molecular weight and crystallinity can be produced, and the blend of physical
properties of PLA makes it suited for a broad range of fiber and packaging applications. Fiber
and non-woven applications include clothing, fiberfill, blankets and wipes. Packaging
applications include packaging films and food and beverage containers.
H. As Nature Works PLA polymers are more oil- and grease-resistant and provide a better
flavor and aroma barrier than existing petroleum-based polymers, grocery retailers are
increasingly using this packaging for their fresh foods. As companies begin to explore this
family of polymers, more potential applications are being identified. For example, PLA
possess two properties that are particularly useful for drape fabrics and window furnishings.
Their resistance to ultraviolet light is particularly appealing as this reduces the amount of
fading in such fabrics, and their refractive index is low, which means fabrics constructed from
these polymers can be made with deep colors without requiring large amounts of dye. In
addition, sportswear makers have been drawn to the product as it has an inherent ability to
take moisture away from the skin and when blended with cotton and wool, the result is
garments that are lighter and better at absorbing moisture.
I. PLA combines inexpensive large-scale fermentation with chemical processing to produce a
value-added polymer product that improves the environment as well. The source material for
PLA is a natural sugar found in plants such as corn and using such renewable feedstock
presents several environmental benefits. As an alternative to traditional petroleum-based
polymers, the production of PLA uses 20%-50% less fossil fuel and releases a lower amount
of greenhouse gasses than comparable petroleum-based plastic; carbon dioxide in the
atmosphere is removed when the feedstock is grown and is returned to the earth when the
polymer is degraded. Because the company is using raw materials that can be regenerated
year after year, it is both cost-competitive and environmentally responsible.
