Glossary of Terms
Anthropocene: The Anthropocene is a relatively new term, having just become widespread in the past twenty years, and point to the world we live in today. Its chief characteristic is that it is understood as the time when human activity came to be the single most powerful and influential force in the earth's environment - that, when the collective activities of human beings came to substantially alter Earth’s surface, atmosphere, oceans, and systems of nutrient cycling. A growing group of scientists argue that the Anthropocene is a new epoch, following the Holocene (11,700 years ago to the present). Pointing to global economies, and most notably the growth of nuclear technology, most researchers mark the period after the Second World War (1945) as the beginning of this new era. The word Anthropocene is derived from Greek and means the “recent age of man.”
Anthropogenic: Scientists use the word “anthropogenic” in referring to environmental change caused or influenced by people, either directly or indirectly. "Anthropo-" comes from Greek, and means having to do with humanity, and "–genic" also comes from Greek and refers to creation. Public debate focuses on whether environmental changes are natural or from human activity. Often, both causes are at work, or one cannot be ruled out. Scientists gather evidence and debate that evidence to derive what is likely. Conpare "naturogenic" - having natural causes. Source: USGA
Dendrochronology: sometimes simply referred to as "tree-ring dating" - the science of dating and interpreting past climate events and trends based on the analysis of tree rings. Tree rings are effective indicators of annual climate, especially of rainfall. It's also one of the most practical and precise "proxy" measures available for histrorical climatology.
El Niño a climate pattern that describes the unusual warming of surface waters in the eastern tropical Pacific Ocean. El Niño is the “warm phase” of a larger phenomenon called the El Niño-Southern Oscillation (ENSO). La Niña, the “cool phase” of ENSO, is a pattern that describes the unusual cooling of the region’s surface waters. El Niño and La Niña are considered the ocean part of ENSO, while the Southern Oscillation is its atmospheric changes. El Niño has an impact on ocean temperatures, the speed and strength of ocean currents, the health of coastal fisheries, and local weather from Australia to South America and beyond. El Niño events occur irregularly at two- to seven-year intervals. However, El Niño is not a regular cycle, or predictable in the sense that ocean tides are. It also produces widespread and sometimes severe changes in the climate. Convection above warmer surface waters bring increased precipitation. Rainfall increases drastically in Ecuador and northern Peru, and it brings droughts to Indonesia and Australia and has major impacts on the length and severity of winter in North America. It is a good example, of cyclical, natural variations in climate that have been known and identified for 100s of years.
Fordism is a term used to describe the stage of economic development characteristic of most 20th-century Western societies. It is used specifically to describe the system of mass production that was pioneered in the early 20th century by the Ford Motor Company, but also more broadly the typical postwar mode of economic growth and its associated political and social order in advanced capitalism. It highlights mass production, standardized production techniques (assembly lines, and coordinated these with mass consumption and state support for large-scale businesses. From a climate history perspective, it highlights the fantastic growth of fossil-fuel dependent production and consumption, enabling the still unending growth of energy consumption and carbon emissions.
Four-field system a manner of rotating crops developed in the English Revolution. While crop rotation had been practiced for centuries it was rarely systemised. The four field system saw farm roughly drawn into quarters with most fields planted in five or six key crops/usages: barley, wheat, turnips and most importantly clover. Turnips were used largely as fodder for livestock, and thus creating high quality manure. Clover fixed nitrogen in soils. Thus, by moving thouhg the four field over the year, soil nutrition was much better maintained and food production increased.
Green Revolution: Is what we might call the most recent "agricultural revolution". It represents the great increase in production of food grains (especially wheat and rice) that resulted in large part from the introduction into developing countries of new, high-yielding varieties, beginning in the mid-20th century. Its early dramatic successes were in Mexico and the Indian subcontinent, and later China and other parts of east Asia. The new varieties require large amounts of chemical fertilizers and pesticides to produce their high yields, raising concerns about cost, potentially harmful environmental effects, and longer-term sustainability. Poor farmers, unable to afford the fertilizers and pesticides, have often reaped even lower yields with these grains than with the older strains, which were better adapted to local conditions and had some resistance to pests and diseases. Many researchers note the parallels between growth of food production under these conditions with the production techniques of Fordism.
Globalization: Globalization describes the growing interdependence of the world’s economies, cultures, and populations, brought about by cross-border trade in goods and services, technology, and flows of investment, people, and information. Countries have built economic partnerships to facilitate these movements over many centuries. But the term gained popularity after the Cold War in the early 1990s, as these cooperative arrangements expanded dramatically, and increasingly shaped everyday modern life. From a climate perspective, it draws our attention to increased production and trade, particularly sophisticated transportation methods of goods and manufacturing via complex international supply chains and ever higher requirements for fossil-fuel based trade and production.
Haber-Bosch process: method of directly synthesizing ammonia from hydrogen and nitrogen, developed by the German physical chemist Fritz Haber. He received the Nobel Prize for Chemistry in 1918 for this method, which made the manufacture of ammonia economically feasible. The method was translated into a large-scale process using a catalyst and high-pressure methods by Carl Bosch, an industrial chemist who won a Nobel Prize in 1931 jointly with Friedrich Bergius for high-pressure studies. Haber-Bosch was the first industrial chemical process to use high temperature and pressure to produce a chemical reaction. For commercial production, the reaction is carried out at pressures ranging from 200 to 400 atmospheres and at temperatures ranging from 400° to 650° C (750° to 1200° F). The Haber-Bosch process is the most economical for the fixation of nitrogen and with modifications continues in use as one of the basic processes of the chemical industry in the world. Modern fertilisers, and thus modern agriculture, are a direct outcome of this process.
Holocene: The Holocene is the period of planetary history from the end of the last Ice Age to the very recent past. The preceding and substantially longer sequence of alternating glacial and interglacial ages is the Pleistocene Epoch. The Holocene is the chronological framework for most of human history. Archaeologists use it as the time standard against which they trace the development of early civilizations.
Ice Age: The last period of sustained deep cold on the planet, one which greatly extended glacial coverage of norther of Europe, Asia and America, and which reduced sea-level and thus coasts far greater than today. What we call "the" Ice Age was the most recent of several Ice Ages geological evidence makes clear have happened over the past two million years. The deep retreat of glaciation also marks the earliest indications of organised human civilisations.
Joules - measure of energy [J], alternatively measured by kilowatts per hour [kW/hr]. Large-scale measures usually indicated in gigajoules [GJ]. An average home might use 100 GJ of energy per year. Smil notes that it requires about 0.1 GJ to make a single kg of glass.
Keeling Curve - a graph based on measurements of the amount of CO2 in the earth's atmosphere. Based on measurements taken at an observatory in Hawaii, it indicates both steady annual rises and seasonal variation. It is the single best indicator of increasing and alarmingly high levels of atmospheric CO2.
Last Glacial Maximum: Very simply, the peak of the last Ice Age. The Last Glacial Maximum (LGM) occurred about 20,000 years ago, during the last phase of the Pleistocene epoch. Measured at the maximum expansion of glacial ice fields into what are now habitable parts of the world. At that time, global sea level was more than 400 feet lower than it is today, and glaciers covered approximately 8 per cent of the earth's surface, as compared with about 3 per cent today.
Little Ice Age: The LIA is the climate interval that occurred from the early 14th century through the mid-19th century, when mountain glaciers expanded at several locations, including the European Alps, New Zealand, Alaska, and the southern Andes, and mean annual temperatures across the Northern Hemisphere declined by 0.8 °C relative to the average temperature between 1000 and 2000 CE. Intense cold period in northern Europe resulted in many of the coldest winters in recorded history, and major reductions in food production. Historians and scientists point to the period 1500–1850, when mountain glaciers expanded to their greatest extent. The Little Ice Age followed the Medieval Warming Period (roughly 900–1300 CE) and preceded the present period of warming that began in the late 19th and early 20th centuries.
Medieval Climate Anomaly: Also known as the Medieval warm period, this period was associated with an unusual temperature rise between roughly between 750 and 1350 AD (the European Middle Ages). The available evidence suggests that at times, some regions experienced temperatures exceeding those recorded during the period between 1960 and 1990. Though predominantly recorded in Europe, south-western North America and in some tropical regions, the Medieval warm period affected both the northern and southern hemispheres. But the temperature increase was not universal, varying across regions of the world, and did not happen simultaneously everywhere. That warmth, combined with new innovations in agriculture, allowed significant expansion of food production in Europe and parts of America, resulting in population growth and urban development in the medieval era.
Megafauna: Megafauna are large animals that roamed the Earth during the Pleistocene, 2.5 million to 11,700 years ago (roughly the end of the last Ice Age). European Megafauna included Woolly Rhinoceroses, Mammoths, Cave Lions and Cave Bears. In North American, Megafauna included Giant Ground Sloths and Sabre-toothed Tigers, and African Megafauna included elephants, giraffes, rhinoceroses and hippopotamuses. Africa's Megafauna is all that remains around today. The extinction of megafauna was probably related to the dramatic changes in temperature followingf the end of the last ice age. But climate historians are also interested in Megafauna in that many see evidence that human hunting may have been responsible for their extinction, marking a very early indication of where human technologies could have profound environmental effects. The combination of naturogenic climate change (that is, naturally occurring change) and anthropogenic effects (in this case, large-scale hunting) best explains the disappearance of the megafauna.
Paleoclimatology is the study of climates (most commonly pre-historic climates) for which direct human measurements are not available. It is highly interdisciplinary relying on expertise from chemists, biologists, archaeologists, and is reliant on advanced technological abilities such as carbon-dating, oxygenation analysis, and pollen dating.
Phytomass - terms commonly used in energy studies to indicate living or recently dead plant matter (biomass from plant sources ) - in energy discussions it usually indicates wood - coal/petroleum are formed from plant/animal sources, but transformed over millions of years.
Proxies: In paleoclimatology, scientists use what is known as proxy data to reconstruct past climate conditions. These proxy data are preserved physical characteristics of the environment that can stand in for direct measurements. Paleoclimatologists gather proxy data from natural recorders of climate variability such as corals, pollen, ice cores, tree rings, caves, packrat middens, ocean and lake sediments, Human produced historical data, such as diaries, account books, images - can also be used to obtain climate data By analyzing records taken from these and other proxy sources, scientists can extend our understanding of climate far beyond the instrumental record.
The 8.2 Climate Event: A 150-year-long colder break in the generally stable temperatures of the Holocene. Global temperatures declined between 2 and 4 °C. A clear indication of volatility, even in consistent climate period.
Renewable energy: The UN defines renewable energy as energy derived from natural sources that are replenished at a higher rate than they are consumed. Sunlight and wind, for example, are such sources that are constantly being replenished. Renewable energy sources are plentiful and all around us. Fossil fuels - coal, oil and gas - on the other hand, are non-renewable resources that take hundreds of millions of years to form. Fossil fuels, when burned to produce energy, cause harmful greenhouse gas emissions, such as carbon dioxide.