December 8, 2012 Tea feels heat from global warming
Tea is the most widely consumed daily beverage in the world. It has a fascinating history that dates back almost 4,800 years; and it too is feeling the effects of a rising, temperature-trapping greenhouse gases.
According to Chinese legend, in 2737 B.C. Emperor Shen Nung was resting under a wild tea tree when a slight breeze caused a few leaves to drift into his cup of boiling water. He found the warm drink both refreshing and invigorating. Tea was discovered.
Interestingly, tea was first used as a medicine. It wasn’t until the 4th and 5th century that tea became a very popular drink throughout China. An entire industry grew around tea. Tea merchants became wealthy. Potters, silversmiths, traders and goldsmiths started to manufacture expensive and elegant pots and cups denoting the wealth and status of their owners.
The Tang Dynasty 618-906 A.D. was known as “The Golden Age of Tea.” Tea leaves were pressed into bricks and orange peels, cloves, ginger and peppermint were added as flavorings.
During the Song Dynasty 960-1279 A.D. growers discovered how to preserve tea leaves by first fermenting them in air until they turned a copper red color and then halting the natural decomposition by baking them.
Japanese records show that in 729 A.D. Emperor Shomu served 100 Buddhist monks, Chinese tea. It wasn’t until 803 A.D. that the first tea seeds were brought from China to Japan. Emperor Saga enjoyed tea so much that he ordered it to be cultivated in five provinces. Tea drinking in Japan is a ceremony. It embraces harmony, respect, purity and tranquility.
Early in the 17th century the Dutch and Portuguese first brought tea to Europe. Portuguese boats from Macao – Mainland China – and Dutch tall-ships from the island of Java carried silks, brocades, spices and tea. Tea soon became very popular in Great Britain and Russia.
In 1618 A.D. Chinese tea was given as a gift to Tsar Alexis. Two hundred and fifty camels each carrying a load of 551 pounds (250 kilograms) trekked from China to the border of Usk Kayakhta. The arduous journey took about 18 months. Tea was traded for Russian furs. And by 1796 Russians were consuming 6,000 camel loads of tea a year. The completion of the Trans-Siberian Railway in 1903 enabled Chinese tea, silks and porcelain to reach Russia in just over one week.
Tea arrived in Britain in 1658 and was very expensive. Tea was consumed by ladies at home and men drank it at coffee houses. Edward Lloyd – founder of Lloyds of London Insurance – started Edward Lloyd’s Coffeehouse. In 1706 Thomas Twining, founder of the famous tea company, opened Tom’s Coffeehouse outside the old city walls of London.
Tea was expensive in England because Charles II taxed it. Britain had an insatiable demand for tea. It grew from 92,594 pounds (42,000 kilograms) in 1701 to 17,636,979 pounds (8 million kilograms) by 1791.
The British East India Company grew opium in Bengal and from 1800 to 1839 traded it to China for tea. In 1840 Britain declared war on China and tea supplies from that nation were cut off.
Britain sourced northern India, Upper Assam first and then Ceylon, now Sri Lanka, to supply its demand for tea. And in 1870 British grocery mogul Thomas Lipton bought a half a dozen plantations in Ceylon and produced and marketed his own tea using the slogan “Direct from the Tea Gardens to the Tea Pot.”
British consumption rose from 28,660,092 pounds (13 million kilograms) in 1801 to 275,577,809 pounds (125 million kilograms) in 1901 and most of the imports came from India and Ceylon.
Tea comes from an evergreen plant in the Camellia family. There are three varieties of tea from China, Assam and Cambodia that are used in plantations.
Camellia sinensis thrives in China, Japan and Tibet, it can reach a height of about 13 feet (4 meters) with 2-inch (5-centimeter) long leaves. It tolerates cold temperatures and can live for a hundred years.
Camellia assamica is a fast growing tree, it can get to 56 feet (17 meters) with leaves over 12-inches (30-centimeters) long, but it only lives for 40 years.
Camellia assamica subsp. lasiocalyx is a tall shrub and is mainly used for the production of hybrids.
The best teas are grown at high elevations above 4,921 feet (1500 meters). Slow growth at high elevation promotes flavor.
Green, oolong and black tea all come from the same plant. The processing methods produce six main types – white, green, oolong, black, scented and compressed tea. There are more than 3,000 kinds of tea around the world (www.mightyleaf.com/).
Tea pickers remove the two leaves from the bud of a new shoot. One picker, working an eight-hour day, can collect 100,000 leaves a day.
Tea leaves contain amino acids, carbohydrates, minerals, caffeine and polyphenols. The aroma of black tea contains over 500 chemicals including hydrocarbons, alcohols and acids. The taste of tea comes primarily from polyphenols and caffeine.
All types of tea – green, oolong and black contain caffeine, but in different quantities. An average cup of green tea contains 8.4 milligrams of caffeine, oolong tea has 12.6 milligrams and black tea 25-110 milligrams, whereas an average cup of coffee contains 60 –120 milligrams.
The caffeine from coffee is absorbed quickly into the body by increasing the heart rate and blood circulation and the cardio vascular system. The polyphenols in tea slow down the rate of caffeine absorption and stay in the body longer. That’s why tea is a more refreshing and invigorating beverage than coffee.
Leaves are graded according to their size and uniformity. Smaller or broken leaves yield a stronger, quicker brew, and they are used in tea bags.
Tea has a wide-range of beneficial qualities. Tea leaves contain fluoride which strengthens teeth, and a host of chemicals that fight plaque and prevent gums disease. Green and black teas reduce the risk of lung, colon and skin cancers. Drinking tea also reduces heart disease, stroke and thrombosis.
The caffeine in tea is a gentle stimulant promoting the heart and circulatory system, and it helps keep the walls of the blood vessels soft thereby reducing the risk of arteriosclerosis (hardening of the arteries).
Tea stimulates the digestive juices, cleanses the kidneys and liver, and removes toxins from the body.
Billions of people from around the globe drink tea every day, including 125 million Americans.
Global warming is weakening the taste of tea. In fact growers in tropical Assam state, India’s main tea-growing region, report that rising temperatures have lead to a drop in production of fine black teas. In 2007, Assam produced 564,000 tons of tea yet by 2009 it had slipped to 487,000 tons. The estimates for 2010 productions look to be around 460,000 tons.
Temperatures have risen in the region by 3.6 degrees Fahrenheit during the last 80 years. In addition, there were fewer sunshine days during the monsoonal season, which has increased the number of damp days. In turn, this has created favorable conditions for the tea mosquito bug which attacks fresh shoots of the tea bush.
Global warming is not just impacting tea production but rather its beginning to badly affect the livelihoods of 3 million people in the tea industry across India; most of them already exist at the poverty line.
Text © by Dr Reese Halter 2012. All rights reserved.
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