An ice age is a long period of reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and greenhouse periods, during which there are no glaciers on the planet. Earth is currently in the Quaternary glaciation, known in popular terminology as the Ice Age.[1] Individual pulses of cold climate within an ice age are termed "glacial periods" (or, alternatively, "glacials", "glaciations", "glacial stages", "stadials", "stades", or colloquially, "ice ages"), and intermittent warm periods within an ice age are called "interglacials" or "interstadials", with both climatic pulses part of the Quaternary or other periods in Earth's history.[2]
In the terminology of glaciology, ice age implies the presence of extensive ice sheets in both northern and southern hemispheres.[3] By this definition, we are in an interglacial period—the Holocene. The amount of heat trapping gases emitted into Earth's oceans and atmosphere are predicted to prevent the next glacial period, which otherwise would begin in around 50,000 years, and likely more glacial cycles.[4][5]
https://en.wikipedia.org/wiki/Ice_age
The causes of ice ages are not fully understood for either the large-scale ice age periods or the smaller ebb and flow of glacial–interglacial periods within an ice age. The consensus is that several factors are important: atmospheric composition, such as the concentrations of carbon dioxide and methane (the specific levels of the previously mentioned gases are now able to be seen with the new ice core samples from EPICA Dome C in Antarctica over the past 800,000 years); changes in the earth's orbit around the Sun known as Milankovitch cycles; the motion of tectonic plates resulting in changes in the relative location and amount of continental and oceanic crust on the earth's surface, which affect wind and ocean currents; variations in solar output; the orbital dynamics of the Earth–Moon system; the impact of relatively large meteorites and volcanism including eruptions of supervolcanoes.[48][citation needed]
Some of these factors influence each other. For example, changes in Earth's atmospheric composition (especially the concentrations of greenhouse gases) may alter the climate, while climate change itself can change the atmospheric composition (for example by changing the rate at which weathering removes CO
2).
2).
Maureen Raymo, William Ruddiman and others propose that the Tibetan and Colorado Plateaus are immense CO
2 "scrubbers" with a capacity to remove enough CO
2 from the global atmosphere to be a significant causal factor of the 40 million year Cenozoic Cooling trend. They further claim that approximately half of their uplift (and CO
2 "scrubbing" capacity) occurred in the past 10 million years.[49][50]
https://en.wikipedia.org/wiki/Ice_age#Causes2 "scrubbers" with a capacity to remove enough CO
2 from the global atmosphere to be a significant causal factor of the 40 million year Cenozoic Cooling trend. They further claim that approximately half of their uplift (and CO
2 "scrubbing" capacity) occurred in the past 10 million years.[49][50]
The Quaternary glaciation, also known as the Pleistocene glaciation, is an alternating series of glacial and interglacial periods during the Quaternary period that began 2.58 Ma (million years ago), and is ongoing.[1][2][3] Although geologists describe the entire time period as an "ice age", in popular culture the term "ice age" is usually associated with just the most recent glacial period during the Pleistocene.[4] Since the planet Earth still has ice sheets, geologists consider the Quaternary glaciation to be ongoing, with the Earth now experiencing an interglacial period.
https://en.wikipedia.org/wiki/Quaternary_glaciation
The Last Glacial Period (LGP) occurred from the end of the Eemian to the end of the Younger Dryas, encompassing the period c. 115,000 – c. 11,700 years ago. This most recent glacial period is part of a larger pattern of glacial and interglacial periods known as the Quaternary glaciation extending from c. 2,588,000 years ago to present.
https://en.wikipedia.org/wiki/Last_Glacial_Period
冰河時期（Ice Age），又稱「冰河期」，是指地球大氣和地表長期低溫導致極地和山地冰蓋大幅擴展甚至覆蓋整個大陸的時期。冰河時期內部又分為幾次冰期（glacial period、glacials或glaciations）與間冰期（interglacials）。
從冰河學的角度，南北半球出現大範圍冰蓋的時期即可視作冰河時期。[1]鑑於格陵蘭和南北極大範圍冰蓋的存在，當今的地球仍處在始於260萬年前更新世的第四紀冰河時期的一次間冰期中，且尚無跡象表明地球正在走出這次冰河時期。
冰期（glacial period），又稱亞冰期，是指在一個「冰河時期」（其時間跨度是幾千萬年甚至2、3億年）之中，一段持續的全球低溫、大陸冰蓋大幅度向赤道延伸的時期。而間冰期是指兩次冰期之間，全球溫度較高，大陸冰蓋大幅度消融退縮的時期。冰期與間冰期的時間尺度是數十萬年。一個冰河時期由冰期、間冰期交替反覆旋迴。目前地球處於第四紀冰河時期，50萬年來出現了5次冰期，每次冰期平均持續7萬多年，而每次間冰期平均持續2萬多年。目前處於1.1萬年前開始的間冰期，這也是全新世的開始.
