Query: "...there is the contention by Wolfgang Knorr of the Department of Earth Sciences at the University of Bristol in England that carbon dioxide levels in the atmosphere are about where they were 160 years ago." (as quoted by Ken Ward Jr.)

Relevant passages:
Ice age <=SEP=> An ice age is a period of long-term reduction in the temperature of Earth 's surface and atmosphere , resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers . Within a long-term ice age , individual pulses of cold climate are termed `` glacial periods '' ( or alternatively `` glacials '' or `` glaciations '' or colloquially as `` ice age '' ) , and intermittent warm periods are called `` interglacials '' . In the terminology of glaciology , ice age implies the presence of extensive ice sheets in both northern and southern hemispheres . By this definition , we are in an interglacial period -- the Holocene -- of the ice age . The ice age began 2.6 million years ago at the start of the Pleistocene epoch , because the Greenland , Arctic , and Antarctic ice sheets still exist .

Botany <=SEP=> Botany , also called plant science ( s ) , plant biology or phytology , is the science of plant life and a branch of biology . A botanist or plant scientist is a scientist who specialises in this field . The term `` botany '' comes from the Ancient Greek word βοτάνη ( botanē ) meaning `` pasture '' , `` grass '' , or `` fodder '' ; βοτάνη is in turn derived from βόσκειν ( boskein ) , `` to feed '' or `` to graze '' . Traditionally , botany has also included the study of fungi and algae by mycologists and phycologists respectively , with the study of these three groups of organisms remaining within the sphere of interest of the International Botanical Congress . Nowadays , botanists ( in the strict sense ) study approximately 410,000 species of land plants of which some 391,000 species are vascular plants ( including ca 369,000 species of flowering plants ) , and ca 20,000 are bryophytes .   Botany originated in prehistory as herbalism with the efforts of early humans to identify -- and later cultivate -- edible , medicinal and poisonous plants , making it one of the oldest branches of science . Medieval physic gardens , often attached to monasteries , contained plants of medical importance . They were forerunners of the first botanical gardens attached to universities , founded from the 1540s onwards . One of the earliest was the Padua botanical garden . These gardens facilitated the academic study of plants . Efforts to catalogue and describe their collections were the beginnings of plant taxonomy , and led in 1753 to the binomial system of Carl Linnaeus that remains in use to this day .   In the 19th and 20th centuries , new techniques were developed for the study of plants , including methods of optical microscopy and live cell imaging , electron microscopy , analysis of chromosome number , plant chemistry and the structure and function of enzymes and other proteins . In the last two decades of the 20th century , botanists exploited the techniques of molecular genetic analysis , including genomics and proteomics and DNA sequences to classify plants more accurately .   Modern botany is a broad , multidisciplinary subject with inputs from most other areas of science and technology . Research topics include the study of plant structure , growth and differentiation , reproduction , biochemistry and primary metabolism , chemical products , development , diseases , evolutionary relationships , systematics , and plant taxonomy . Dominant themes in 21st century plant science are molecular genetics and epigenetics , which are the mechanisms and control of gene expression during differentiation of plant cells and tissues . Botanical research has diverse applications in providing staple foods , materials such as timber , oil , rubber , fibre and drugs , in modern horticulture , agriculture and forestry , plant propagation , breeding and genetic modification , in the synthesis of chemicals and raw materials for construction and energy production , in environmental management , and the maintenance of biodiversity .

Eocene <=SEP=> The Eocene ( -LSB- pronˈiːəˌsiːn , _ ˈiːoʊ - -RSB- ) Epoch , lasting from , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era . The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch . The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C . The end is set at a major extinction event called the Grande Coupure ( the `` Great Break '' in continuity ) or the Eocene -- Oligocene extinction event , which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay . As with other geologic periods , the strata that define the start and end of the epoch are well identified , though their exact dates are slightly uncertain .   The name Eocene comes from the Ancient Greek ἠώς ( ēṓs , `` dawn '' ) and καινός ( kainós , `` new '' ) and refers to the `` dawn '' of modern ( ` new ' ) fauna that appeared during the epoch .