Climate sensitivityClimate sensitivity is a measure of how much Earth's surface will cool or warm after a specified factor causes a change in its climate system, such as how much it will warm for a doubling in the atmospheric carbon dioxide () concentration. In technical terms, climate sensitivity is the average change in global mean surface temperature in response to a radiative forcing, which drives a difference between Earth's incoming and outgoing energy.
VegetationVegetation is an assemblage of plant species and the ground cover they provide. It is a general term, without specific reference to particular taxa, life forms, structure, spatial extent, or any other specific botanical or geographic characteristics. It is broader than the term flora which refers to species composition. Perhaps the closest synonym is plant community, but vegetation can, and often does, refer to a wider range of spatial scales than that term does, including scales as large as the global.
Climate modelNumerical climate models use quantitative methods to simulate the interactions of the important drivers of climate, including atmosphere, oceans, land surface and ice. They are used for a variety of purposes from study of the dynamics of the climate system to projections of future climate. Climate models may also be qualitative (i.e. not numerical) models and also narratives, largely descriptive, of possible futures.
QuaternaryThe Quaternary (kwəˈtɜrnəri,_ˈkwɒtərnɛri ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ago to the present. The Quaternary Period is divided into two epochs: the Pleistocene (2.58 million years ago to 11.7 thousand years ago) and the Holocene (11.7 thousand years ago to today) although a third epoch, the Anthropocene, has been proposed but is not officially recognised by the ICS.
Quaternary extinction eventThe latter half of the Late Pleistocene to the beginning of the Holocene (~50,000-10,000 years Before Present) saw extinctions of numerous predominantly megafaunal species, which resulted in a collapse in faunal density and diversity across the globe. The extinctions during the Late Pleistocene are differentiated from previous extinctions by the widespread absence of ecological succession to replace these extinct megafaunal species, and the regime shift of previously established faunal relationships and habitats as a consequence.
Quaternary scienceQuaternary science is the subfield of geology which studies the Quaternary Period commonly known as the ice age. The Quaternary Period is a time period that started around 2.58 million years ago and continues today. This period is divided into two epochs – the Pleistocene Epoch and the Holocene Epoch. The aim of Quaternary science is to understand everything that happened during the Pleistocene Epoch and the Holocene Epoch to be able to acquire fundamental knowledge about Earth's environment, ecosystem, climate changes, etc.
HoloceneThe Holocene (ˈhɒl.əsiːn,_-oʊ-,ˈhoʊ.lə-,-loʊ-) is the current geological epoch. It began approximately 11,700 years before 2000 CE (11,650 cal years BP, 9700 BCE or 300 HE). It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1. It is considered by some to be an interglacial period within the Pleistocene Epoch, called the Flandrian interglacial.
Tipping points in the climate systemIn climate science, a tipping point is a critical threshold that, when crossed, leads to large and often irreversible changes in the climate system. If tipping points are crossed, they are likely to have severe impacts on human society. Tipping behavior is found across the climate system, in ecosystems, ice sheets, and the circulation of the ocean and atmosphere. Tipping points are often, but not necessarily, abrupt. For example, with average global warming somewhere between and , the Greenland ice sheet passes a tipping point and is doomed, but its melt would take place over millennia.
Quaternary glaciationThe 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. Although geologists describe this entire period up to the present as an "ice age", in popular culture this term usually refers to the most recent glacial period, or to the Pleistocene epoch in general. Since Earth still has polar ice sheets, geologists consider the Quaternary glaciation to be ongoing, though currently in an interglacial period.
North AmericaNorth America is a continent in the Northern Hemisphere almost entirely within the Western Hemisphere. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the west and south by the Pacific Ocean. The region includes Canada, the Caribbean, Central America, Greenland, Mexico, and the United States. North America covers an area of about , representing approximately 16.5% of the Earth's land area and 4.
