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Wikipedia card geology geological time periods climate climate based on geological investigation of the evidence (material composition, sedimentary structural features and biological fossils) infer the geological age of the Earth's climate. Also known paleoclimate.

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A brief history of climate change because the history of research methods research history Edit this paragraph in the history of global climate change has long been noticed some traces left behind. China's Shen Kuo Northern Song Dynasty, from the formation and characteristics of fossils in geological time judged the climate changes occurred and the evolution of sea Diego. In 1840, the Swiss Alps mountain JLR Agassiz glaciers deposited under the first time in the history of the Earth's climate clearly there had been glacial climate. Early 20th century, German A. Penck and E. Bruckner published "Alpine glaciation," a book that will Alps mountain is divided into four Quaternary glacial glaciation (later divided into five glacial), For comparison between two glacial interglacial warm. This division was later recognized as Quaternary glacial staging international standards. In other continent, but later found accordingly and paleontological remains of ancient glaciers. China in ancient glacier study, confirmed earlier in the western mountain glaciers, glaciers on the east, and there have been a lot of research. Edit this paragraph in the climate history of billions of years of geological history, the global-scale expansion and shrinking snow-covered interchangeably, sometimes covered with a large area of ​​continental ice sheets and glaciers, cold climate, this period is called the Ice Age (but also said the Great Ice Age); relatively large ice sheets and glaciers to advance to the low-latitude regions, also called the Ice Age. Comparison between two glacial warm period between, glaciers retreat, called interglacials. This time scale fluctuations of heat and cold about 106 to 108 years. Since the Precambrian, more than 90% of the time, the two hemispheres of the polar ice. However, there have been at least three major global glaciation, more accepted are: Precambrian glacial maximum (dating back about 600 million years ago), Carboniferous - Permian glaciation (2-3 million years ago) and Quaternary Great Ice Age (200 to 300 million years ago to 1 to 2 years). Precambrian, there may be another big ice age,Adidas AdiPure FG, but lack of information, yet can not judge. Generally, the temperature of the geological period estimated from the Mesozoic (2.3 ~ 067 million years ago) since it is more reliable. At the time the annual average temperature near the poles of 8 ~ 10 ° C, the equator is 25 ~ 30 ° C. Climate Tertiary Tertiary (dating back 067 million years to 200 to 300 million years) of the main climatic features are: mid-latitudes the temperature gradually decreased (see Figure), about 14 million years ago, the Earth's temperature dropped sharply , first appeared in the Antarctic ice sheet, at 2.5 million years ago,mercurial 2012, the Icelandic mountain glaciers appeared, followed by the Northern Hemisphere high latitudes also formed ice. Quaternary Quaternary climate from about three million years ago started until now. Quaternary glaciers and polar climate in the high latitudes of the mountain glaciers cover as the main feature, also known as the Quaternary glacial maximum. In the Quaternary, the changes in the area covered by glaciers, can be divided into several glacial and interglacial periods. Their ice cover, respectively, accounting for 30% of the land surface and about 10%. But in the major land-based ice age, glaciers are very different degree of development. For example, the European continental ice sheet had reached latitude 48 °, and northern Asia, Siberia smaller ice caps, only reached latitude 60 °. China no large ice sheet, but the western mountains, such as Altai, Tianshan, Qilian Mountain, Yulong, western Sichuan and the Tibetan Plateau, but development of mountain glaciers. As climate change with regional differences and different research methods, divided over different periods of ice. For example: In Europe, the Alps mountain Quaternary glacial maximum was divided into the Danube, Gongzi, Minde, Reese, Wu wooden five glacial; in southwest China's Himalayan region, divided Xixiabangma, Nie Nie male Pull Everest three glacial; in eastern China, Li siguang has carved out Poyang, Aunt, Lushan, Dali four glacial. But the division of the Quaternary Ice Age around China inconclusive, some people think there is no eastern China in the Quaternary glacial activity. Quaternary glacial and interglacial temperature amplitude sea around 6 ° C, which is from the tropical waters of the North Atlantic seabed cores obtained. In addition to higher Arctic waters, other ocean areas were slightly lower than this figure. Interglacial North Atlantic tropical waters more modern high 1 ° C. Temperature fluctuations on the continent, in the ice edge regions such as Europe, about 12 ° C, but at the alpine snow line was 4 ~ 6 ° C. Glacial and interglacial great changes in temperature, causing other climatic factors and changes in physical geography factors: ① rain with changes in the distribution. Glacial ice sheets expand the area of ​​the polar anticyclone enhanced polar high pressure zone to the middle and low latitudes expansion, forcing the planet polar front zone (see Feng, rapids) moved to middle and low latitudes, resulting in low latitudes lower Pressure activity is frequent rainfall, the lake area to expand. For example, Central Asia, North Africa and Central America, North America and western, both in glacial humid regions. But in interglacial, the climate in these areas often very dry. ② snow line lift. Glacial, global general decline in mountain snow line, most mountain snow line dropped from 1000 to 1400 m, the snow line in tropical regions decreased from 700 to 900 m. ③ sea level rise and fall. Glacial water in the Earth's surface, a large part of the formation of a huge ice sheet and stay on land, sea level thus reducing such weapons wood glacial sea about 100 meters lower than modern. In the warmest interglacial periods of the sea, may be higher than 15 to 30 meters of modern, or even more. ④ biome migration. In the glacial glacier expansion, climate zones shift towards lower latitudes; interglacial period, glaciers retreat, polar temperatures, climate zones shift towards high latitudes. And climatic zones corresponding, biological communities also will migrate north and south. For example, the Crimea (Reese Ice Age) strata found over arctic fox, arctic deer; in the South Caucasus, from the Ice Age mammoth fossils discovered in strata, these are polar animals. In interglacial, Arctic coastal tiger, musk ox and other thermophilic fauna activity. Postglacial postglacial climatic ten thousand years ago, global temperatures gradually increased, the area covered by glaciers shrink accordingly, sea level rise, the warmer the Earth's climate has entered a period (see historical climate). Edit this paragraph causes of change on various time scales causes of climate change, there are many kinds of hypotheses. To sum up can be divided into the following five kinds: ① Astronomy hypothesis. Astronomical factors that change will cause climate change. As the Yugoslav mathematician M. Milankovitch combines the eccentricity of Earth's orbit, tilt, and precession of the ecliptic astronomical factors such as possible changes to calculate the latitude 45 ° ~ 70 ° zone 60 years since the summer, the amount of radiation curve, and to change the amount of radiation converted into the corresponding latitude. Calculation, with the establishment of the Alps Penck Quaternary temperature change model is very similar. ② atmospheric physics hypothesis. That changes in solar radiation or atmospheric transparency (see atmospheric extinction) changes can be caused by climate change. Since the intensity of solar activity changes, so that the total radiation reaching the earth (including electromagnetic and particle flow energy) change. When the radiation is reduced, the temperature dropped on Earth, there glaciation. Radiation increases, the temperature rises into the interglacial. Another scenario is that because of volcanic obvious resting and activity, and the resulting changes in atmospheric transparency, leading to climate change. For example, a large volcanic eruptions of lava, smoke and various gases in the stratosphere to form dust curtain, affecting the transparency of the atmosphere,nike indoor soccer shoes 2013, the solar radiation reaching the Earth's surface to reduce the temperature decreased. A volcanic eruption can affect the subsequent 10 to 15 years of climate, if the frequent volcanic eruptions, dust curtain cumulative effect may lead to climate cooling trend. ③ geology geography hypothesis. That the pole moves, changes in the distribution of land and sea and tectonic movements, etc., can cause climate change. Which used the argument to explain continental drift climate change, the most attention. This point of view, any local temperature decreases and the accumulation of glaciers, are due to the block of continental drift caused by the higher latitudes. For example Colombo is now located at latitude 7 ° around a tropical climate, but it is located in the Carboniferous near latitude 82 °, so there have been polar climate. Also predicament match times Bergen archipelago, now located at latitude 79 ° near the polar climate, but in the Carboniferous it is located at latitude 24 °, for the tropical climate. Edit this paragraph geological periods of climate research methods research involves finding evidence of paleoclimate evidence and determine the age of (called break-generation technology) in two steps. The former method can be used geology, geography methods and isotopic methods (physical method) and so on. Geology method is based on the biological living conditions, rock formations and sedimentary deposits formation and the relationship between climate, through the formation of fossils and sediments and other characteristics of study to clarify geological periods of time and climate in spatial distribution and changes in the law . For example, the presence of coal, can be inferred for the humid climate; emerge coral reefs, inferred for the warm climate; gypsum, rock salt, dry climate inferred as such. In addition, you can also plant pollen formation (of plants spread out during the breeding period of spores and pollen in general) analysis speculate climate. When the pollen mother left, you spilled on the soil surface, and was buried in layers of soil or peat layer. Since pollen huge number (for example, one year may be spread out beech 400 million pollen), in the case of air separation, can be survived long, so that, according to the pollen parent plant to determine the shape of the species, as speculated ancient vegetation and its corresponding climatic basis. For example, in southern Liaoning China dating back 8,000 to 10,000 years of peat layer, the birch pollen predominate, while birch forest has now retreat to the size of the Mountains and the Changbai Mountain area. Birch is a cold-drought-tolerant plants, indicating that the climate of southern Liaoning then than it is now dry and cold. Isotope method in the 1940s began to develop, in which the oxygen isotope method most widely used. For example, the use of oxygen isotope ratios can be measured in different polar ice sheets formed when the temperature of the ice conditions. -16 Aerobic nature of the oxygen, oxygen -17, -18 three isotopes of oxygen. The ice is formed, the lower the temperature, in which the oxygen and oxygen -16 -18 The higher the ratio, therefore, according to the ratio of oxygen-18 and oxygen -16 changes, then converted into temperature. Analysis of ocean floor globigerina ooze oxygen isotope ratios, we can understand the Quaternary sea surface temperature changes, oxygen isotope method is also used to determine the formation of stalactites and tree ring temperature. The use of carbon-14 and carbon-13 ratio, the temperature can be speculated that the ancient, but not widely applied. Geography method is mainly used to examine a variety of natural and geographical factors of change, such as sea-level rise and fall, rivers and lakes water level changes, the advance and retreat of glaciers and the snow line, such as deserts and tundra and forest boundaries goes to estimate the corresponding climate evolution. Dating evidence for the formation of a variety of techniques to determine the sequence and chronology. Can be divided into relative dating and absolute dating. Relative dating only shows evidence of the formation of the old and new order on time, be divided mainly based on paleontological methods, such as pollen dating, stratigraphic dating and so on. Absolute dating is clear evidence of the formation of the absolute age given, mainly based on the decay products of radioactive isotopes in rocks of the content to be determined.