Query: Scientists have long known about the anomalous ‘warming hole‘ in the North Atlantic Ocean, an area immune to warming of Earth’s oceans.

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Climate <=SEP=> Climate is the statistics of weather , usually over a 30-year interval . It is measured by assessing the patterns of variation in temperature , humidity , atmospheric pressure , wind , precipitation , atmospheric particle count and other meteorological variables in a given region over long periods of time . Climate differs from weather , in that weather only describes the short-term conditions of these variables in a given region .   A region 's climate is generated by the climate system , which has five components : atmosphere , hydrosphere , cryosphere , lithosphere , and biosphere .   The climate of a location is affected by its latitude , terrain , and altitude , as well as nearby water bodies and their currents . Climates can be classified according to the average and the typical ranges of different variables , most commonly temperature and precipitation . The most commonly used classification scheme was the Köppen climate classification . The Thornthwaite system , in use since 1948 , incorporates evapotranspiration along with temperature and precipitation information and is used in studying biological diversity and how climate change affects it . The Bergeron and Spatial Synoptic Classification systems focus on the origin of air masses that define the climate of a region .   Paleoclimatology is the study of ancient climates . Since direct observations of climate are not available before the 19th century , paleoclimates are inferred from proxy variables that include non-biotic evidence such as sediments found in lake beds and ice cores , and biotic evidence such as tree rings and coral . Climate models are mathematical models of past , present and future climates . Climate change may occur over long and short timescales from a variety of factors ; recent warming is discussed in global warming . Global warming results in redistributions . For example , `` a 3 ° C change in mean annual temperature corresponds to a shift in isotherms of approximately 300 -- 400 km in latitude ( in the temperate zone ) or 500 m in elevation . Therefore , species are expected to move upwards in elevation or towards the poles in latitude in response to shifting climate zones '' .

Cretaceous <=SEP=> The Cretaceous ( -LSB- pronkrᵻˈteɪʃəs -RSB- , ) is a geologic period and system that spans 79 million years from the end of the Jurassic Period million years ago ( Mya ) to the beginning of the Paleogene Period Mya . It is the last period of the Mesozoic Era . The Cretaceous Period is usually abbreviated K , for its German translation Kreide ( chalk ) .   The Cretaceous was a period with a relatively warm climate , resulting in high eustatic sea levels that created numerous shallow inland seas . These oceans and seas were populated with now-extinct marine reptiles , ammonites and rudists , while dinosaurs continued to dominate on land . During this time , new groups of mammals and birds , as well as flowering plants , appeared . The Cretaceous ended with a large mass extinction , the Cretaceous -- Paleogene extinction event , in which many groups , including non-avian dinosaurs , pterosaurs and large marine reptiles died out . The end of the Cretaceous is defined by the abrupt Cretaceous -- Paleogene boundary ( K -- Pg boundary ) , a geologic signature associated with the mass extinction which lies between the Mesozoic and Cenozoic eras .

Atlantic Ocean <=SEP=> The Atlantic Ocean is the second largest of the world 's oceans with a total area of about 106,460,000 km2 . It covers approximately 20 percent of the Earth 's surface and about 29 percent of its water surface area . It separates the `` Old World '' from the `` New World '' .   The Atlantic Ocean occupies an elongated , S-shaped basin extending longitudinally between Eurasia and Africa to the east , and the Americas to the west . As one component of the interconnected global ocean , it is connected in the north to the Arctic Ocean , to the Pacific Ocean in the southwest , the Indian Ocean in the southeast , and the Southern Ocean in the south ( other definitions describe the Atlantic as extending southward to Antarctica ) . The Equatorial Counter Current subdivides it into the North Atlantic Ocean and South Atlantic Ocean at about 8 ° N.   Scientific explorations of the Atlantic include the Challenger expedition , the German Meteor expedition , Columbia University 's Lamont-Doherty Earth Observatory and the United States Navy Hydrographic Office .

Little Ice Age <=SEP=> The Little Ice Age ( LIA ) was a period of cooling that occurred after the Medieval Warm Period . Although it was not a true ice age , the term was introduced into scientific literature by François E. Matthes in 1939 . It has been conventionally defined as a period extending from the 16th to the 19th centuries , but some experts prefer an alternative timespan from about 1300 to about 1850 . Climatologists and historians working with local records no longer expect to agree on either the start or end dates of the period , which varied according to local conditions .   The NASA Earth Observatory notes three particularly cold intervals : one beginning about 1650 , another about 1770 , and the last in 1850 , all separated by intervals of slight warming . The Intergovernmental Panel on Climate Change Third Assessment Report considered the timing and areas affected by the Little Ice Age suggested largely-independent regional climate changes rather than a globally-synchronous increased glaciation . At most , there was modest cooling of the Northern Hemisphere during the period .   Several causes have been proposed : cyclical lows in solar radiation , heightened volcanic activity , changes in the ocean circulation , variations in Earth 's orbit and axial tilt ( orbital forcing ) , inherent variability in global climate , and decreases in the human population .