The 4th millennium BC spanned the years 4000 BC to 3001 BC. Some of the major changes in human culture during this time included the beginning of the Bronze Age and the invention of writing, which played a major role in starting recorded history.
Paleoclimatology is the scientific study of climates predating the invention of meteorological instruments, when no direct measurement data were available. As instrumental records only span a tiny part of Earth's history, the reconstruction of ancient climate is important to understand natural variation and the evolution of the current climate.
An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper ones, and an ice core contains ice formed over a range of years. Cores are drilled with hand augers or powered drills; they can reach depths of over two miles (3.2 km), and contain ice up to 800,000 years old.
Willi Dansgaard was a Danish paleoclimatologist. He was Professor Emeritus of Geophysics at the University of Copenhagen and a member of the Royal Danish Academy of Science and Letters, the Royal Swedish Academy of Sciences, the Icelandic Academy of Sciences, and the Danish Geophysical Society.
The Byrd Polar and Climate Research Center (BPCRC) is a polar, alpine, and climate research center at The Ohio State University founded in 1960.
Marie Byrd Land (MBL) is an unclaimed region of Antarctica. With an area of 1,610,000 km2 (620,000 sq mi), it is the largest unclaimed territory on Earth. It was named after the wife of American naval officer Richard E. Byrd, who explored the region in the early 20th century.
The global temperature record shows the fluctuations of the temperature of the atmosphere and the oceans through various spans of time. There are numerous estimates of temperatures since the end of the Pleistocene glaciation, particularly during the current Holocene epoch. Some temperature information is available through geologic evidence, going back millions of years. More recently, information from ice cores covers the period from 800,000 years before the present time until now. A study of the paleoclimate covers the time period from 12,000 years ago to the present. Tree rings and measurements from ice cores can give evidence about the global temperature from 1,000-2,000 years before the present until now. The most detailed information exists since 1850, when methodical thermometer-based records began. Modifications on the Stevenson-type screen were made for uniform instrument measurements around 1880.
The retreat of glaciers since 1850 is well documented and is one of the effects of climate change. The retreat of mountain glaciers, notably in western North America, Asia, the Alps and tropical and subtropical regions of South America, Africa and Indonesia, provide evidence for the rise in global temperatures since the late 19th century. The acceleration of the rate of retreat since 1995 of key outlet glaciers of the Greenland and West Antarctic ice sheets may foreshadow a rise in sea level, which would affect coastal regions. Excluding peripheral glaciers of ice sheets, the total cumulated global glacial losses over the 26-year period from 1993 to 2018 were likely 5500 gigatons, or 210 gigatons per yr.
Furtwangler Glacier is located near the summit of Mount Kilimanjaro in Tanzania. The glacier is named after Walter Furtwängler who, with Siegfried König, formed the fourth party to ascend to the summit of Kilimanjaro in 1912.
Dome Fuji, also called Dome F or Valkyrie Dome, is an Antarctic base located in the eastern part of Queen Maud Land at 77°30′S37°30′E. With an altitude of 3,810 metres (12,500 ft) above sea level, it is the second-highest summit or ice dome of the East Antarctic Ice Sheet and represents an ice divide. Dome F is the site of Dome Fuji Station, a research station operated by Japan.
Richard Blane Alley is an American geologist and Evan Pugh Professor of Geosciences at Pennsylvania State University. He has authored more than 240 refereed scientific publications about the relationships between Earth's cryosphere and global climate change, and is recognized by the Institute for Scientific Information as a "highly cited researcher."
Ellen Mosley-Thompson is a glaciologist and climatologist. She is a Distinguished University Professor at The Ohio State University and director of their Byrd Polar and Climate Research Center. She is known as a pioneer in the use of ice cores from the Polar Regions for paleoclimatic research and is an influential figure in climate science. She is an elected fellow of the American Association for the Advancement of Science, the American Geophysical Union and an elected member of the National Academy of Sciences.
Nerilie Abram is an Australian professor at the ANU Research School of Earth Sciences, Australian National University, Canberra, Australia. Her areas of expertise are in climate change and paleoclimatology, including the climate of Antarctica, the Indian Ocean Dipole, and impacts on the climate of Australia.
The Northern Ice Field is near the summit of Mount Kilimanjaro in Tanzania, on the west slope of the peak. The Northern Ice Field and Eastern Ice Fields were connected to the Southern Ice Field and formed part of a continuous body of glacial ice atop Mount Kilimanjaro when first scientifically examined in 1912. By 1962 the Southern Ice Field separated from the Northern Ice Field and then by 1975 the Eastern Ice Field did as well. In 1912, the glaciated areas atop Mount Kilimanjaro covered 11.40 square kilometres (4.40 sq mi); by 2011 this had been reduced to 1.76 square kilometres (0.68 sq mi), an 85 percent loss. At one time, ice flowing off the Northern Ice Field fed numerous glaciers, including, north to south, the Credner, Drygalski, Great Penck and Little Penck Glaciers.
Amy Leventer is an American Antarctic researcher specialising in micropaleontology, with specific research interests in marine geology, marine biology, and climate change. Leventer has made over a dozen journeys to the Antarctic, which began at the age of 24 and led to the pursuit of her PhD.
Julie Michelle Palais is an American polar glaciologist who has made significant contributions to climate change research studying volcanic fallout in ice cores from both Greenland and Antarctica. For many years, starting in 1990, she played a pivotal role working at the National Science Foundation (NSF) as Program Director of the Antarctic Glaciology Program in the Division of Polar Programs, including many trips to both North and South Polar regions. Both the Palais Glacier and Palais Bluff in Antarctica were named in her honor and she has received many further recognitions for her distinguished career.
Martin J. Siegert is a British glaciologist, a professor at Imperial College London, and co-director of the Grantham Institute - Climate Change and Environment.
The Quelccaya Ice Cap is the second largest glaciated area in the tropics, after Coropuna. Located in the Cordillera Oriental section of the Andes mountains in Peru, the cap covers an area of 42.8 square kilometres (16.5 sq mi) with ice up to 200 metres (660 ft) thick. It is surrounded by tall ice cliffs and a number of outlet glaciers, the largest of which is known as Qori Kalis Glacier; lakes, moraines, peat bogs and wetlands are also present. There is a rich flora and fauna, including birds that nest on the ice cap. Quelccaya is an important source of water, eventually melting and flowing into the Inambari and Vilcanota Rivers.
Jérôme Chappellaz is a French glaciologist, geochemist and paleoclimatologist who is director of the French Polar Institute. A senior researcher at France's National Center for Scientific Research (CNRS), he is a co-founder and chairman of the Ice Memory Foundation.
