“Quotation：will this winter be another warm one or a particularly cold one？Since the winter doesn’t go by,no one can say for sure.”Such words appeared in the December,2007 issue of Natural History. One month later,unexpectedly snow fell widely in southern China,what was worse,it was snowstorm. It seemed these words were a prophecy. Otherwise,why did the editor raise such a question amid the loud voice of global warming. Unfortunately,the editor is not a wizard,because her mastered knowledge tells her that the performance of Global Warming does not necessarily mean“hot”,but it may be“cold”.Moreover,regardless of that the Earth is warming or cooling,the current climate is not too abnormal！

 Next,we extracted some pictures from Natural History,hoping to help understand the disaster,the scientific view of climate,disaster prevention from injury,etc...

 

 

China's Climate Changes in History

 

The Movement of Oranges （contributed picture/overall view）

 In the Tang Dynasty,oranges once have been grown in the palace in the capital city Chang’an（now Xi'an, Shaanxi Province）. After they beared fruit,the emperor distributed oranges to to ministers. Oranges can only withstand the temperature of minus 8 degrees Celsius,now Shannxi is colder and oranges can not adapt to being grown there. In the cold Qing Dynasy,oranges grown in Jiangxi have been frozen to death.

 

 

Icebound River（contributed picture/overall view）

Generally,water freezes at zero degree. However,icebound river happens at lower temperature since the river is liquid or contains some impurities or else. Now southern China and northern China are divided by the dividing line Qingling Mountains-Huai River. Frozen river will not happen in the parts in the south of this line,and Huai River itself does not freeze. However,during the Three-Kingdom Period,Huai River once has frozen which delayed Cao Chao’s plan to chain his navy. 

 

 

Snowfall in Guangzhou（contributed picture/overall view）  

Since the Tang Dynasty, there has had specialized tribute of the tangerine groves and citrus orchard to the imperial court in Jiangxi Province. The cold surges in the year 1654 and 1676 destroyed all the tangerine trees and citus trees. During the interval of 50 years,icebound river has occurred in China’s Taihu Lake,Han River and Huai River for four times,and there times for the Dongting Lake,even Poyang Lake,which is located in the south of China,once has witnessed icebound phenomenon. In the eighteenth year of Guangxu Emperor（1892—893）,the Qiantang River in Hangzhou was completely frozen,and “the frozen river looked like plain”. Heavy snow fell throughtout Guangzhou,and the snow laid one-foot thick in some places. At that time,the frozen period around Beijing was 50 days longer than that at present.

Warming caused Ice Age？

Witten by   Cui Peng,Liu Tingwen

 Living in the times of global warming,we’d better move to northern China？It sounds a good idea. But the scientists who study the climate change will absolutely object it. Since it is getting warmer,it might lead to the coming of Ice Age,when the temperate regions we are living in will be likely to become the world of ice.

    

Warming leads to the cold？It sounds contradictory, but it is true. The crux of the issue lies in an unexpected thing—the salt in seawater of the North Atlantic Ocean. But it is this thing which seems nothing in our daily life that can make New York, Tokyo, Beijing and Shanghai disappear from the earth！

This is not an alarmist. If you know the role of sea salt,you will know its formidablity. On the Earth most of the areas are covered by the sea. Aothough we divided the sea into “four oceans” according to geographical location,in fact they are mutually connected. Among the Pacific Ocean,the Atlantic Ocean and the Indian Oceans,there is an enormous ocean currents circulatory system—Thermohaline Circulation.

If we draw the big circulation on the world map,it looks like the Earth’s artery and vein,whose blood flow is the “heat”— this cycle causes the heat from the hot low-latitude regions to pass to the cold high latitudes,playing an important role of coordinating the“cold and heat”on the Earth. If the blood circulation in our human body is impeded,it will lead to stroke andl imb necrosis. If the temperature cycle of the ocean salt is sluggish,the heat distribution on the Earth will be unven.

Blood circulation in human body relies on the heart beat, while the ocean circulation is connected with the difference of salinity of seawater. The high-salinity water is heavier than the low-salinity water,and the gravity becomes the power to push the seawater to flow. What concerns us is that the salinity of seawater in the North Atlantic Ocean dropped over the past 30 years！The speculated cause is the Arctic glaciers—The glaciers absorb more solar energy due to the increasing carbon dioxide concentration in the atmosphere,leading to quicken the pace of melting.

Scientists drew a concrete analogies：The fresh water is just like an enormous blanket covering on the northern Atlantic Ocean.,hindering the warm current from the south. If this situation continues, one day the entire system may stop cycling,and the current will not be able to carry heat from the tropical zone to the mid and high latitudes,affecting the atmospheric movement,eventually leading to a sharp decline of heat in the North America and the Eurasian Continent and triggering  the arrival of the Little Ice Age！The movie "The Day After Tomorrow" is carried out in accordance with this principle,but the Earth is unlikely to enter the Ice Age in a few days. However, in decades or several hundred years,it is indeed possible.

In January of this year,the snowstorm in southern China is mainly connected with the "La Nina" phenomenon. La Nina phenomenon is also connected with the ocean currents,which is caused by the abnormity of the Pacific Ocean current cycling and the atmospheric circulation. Its mechanism is opposite to the "El Nino". The La Nina phenomenon is that the east wind circulation near the equator regions in the Pacific Ocean becomes stronger,and the temperature of the seawater in the east coast（sea areas around Peru, Ecuador and other countries）drops. However,in the western Pacific region—humid air mass in the Southeast Asian region increases and makes the space above the the East Asian continent favorable for the north-south movement of air mass. For the general role,on the one hand,the vapor-rich air mass from the south increases；on the other hand,the cold air mass from the north easily moves southwards. When the two masses meet together,it will lead to heavy snow and freezing rain in southern China.