Query: The planet's average surface temperature has risen about 1.62 degrees Fahrenheit (0.9 degrees Celsius) since the late 19th century, a change driven largely by increased carbon dioxide and other human-made emissions into the atmosphere.

Relevant passages:
Earth <=SEP=> Earth ( from Eorðe -LSB- Γαῖα , Gaia -RSB- Terra ) , otherwise known as the World or the Globe , is the third planet from the Sun and the only object in the Universe known to harbor life . It is the densest planet in the Solar System and the largest of the four terrestrial planets .   According to radiometric dating and other sources of evidence , Earth formed about 4.54 billion years ago . Earth 's gravity interacts with other objects in space , especially the Sun and the Moon , Earth 's only natural satellite . During one orbit around the Sun , Earth rotates about its axis over 365 times ; thus , an Earth year is about 365.26 days long . Earth 's axis of rotation is tilted , producing seasonal variations on the planet 's surface . The gravitational interaction between the Earth and Moon causes ocean tides , stabilizes the Earth 's orientation on its axis , and gradually slows its rotation .   Earth 's lithosphere is divided into several rigid tectonic plates that migrate across the surface over periods of many millions of years . About 71 % of Earth 's surface is covered with water , mostly by its oceans . The remaining 29 % is land consisting of continents and islands that together have many lakes , rivers and other sources of water that contribute to the hydrosphere . The majority of Earth 's polar regions are covered in ice , including the Antarctic ice sheet and the sea ice of the Arctic ice pack . Earth 's interior remains active with a solid iron inner core , a liquid outer core that generates the Earth 's magnetic field , and a convecting mantle that drives plate tectonics .   Within the first billion years of Earth 's history , life appeared in the oceans and began to affect the Earth 's atmosphere and surface , leading to the proliferation of aerobic and anaerobic organisms . Some geological evidence indicates that life may have arisen as much as 4.1 billion years ago . Since then , the combination of Earth 's distance from the Sun , physical properties , and geological history have allowed life to evolve and thrive . In the history of the Earth , biodiversity has gone through long periods of expansion , occasionally punctuated by mass extinction events . Over 99 % of all species that ever lived on Earth are extinct . Estimates of the number of species on Earth today vary widely ; most species have not been described . Over 7.4 billion humans live on Earth and depend on its biosphere and minerals for their survival . Humans have developed diverse societies and cultures ; politically , the world has about 200 sovereign states .

Carbon dioxide <=SEP=> Carbon dioxide ( chemical formula ) is a colorless gas with a density about 60 % higher than that of air ( 1.225 g/L ) that is odorless at normally encountered concentrations . Carbon dioxide consists of a carbon atom covalently double bonded to two oxygen atoms . It occurs naturally in Earth 's atmosphere as a trace gas at a concentration of about 0.04 percent ( 400 ppm ) by volume . Natural sources include volcanoes , hot springs and geysers , and it is freed from carbonate rocks by dissolution in water and acids . Because carbon dioxide is soluble in water , it occurs naturally in groundwater , rivers and lakes , ice caps , glaciers and seawater . It is present in deposits of petroleum and natural gas .   As the source of available carbon in the carbon cycle , atmospheric carbon dioxide is the primary carbon source for life on Earth and its concentration in Earth 's pre-industrial atmosphere since late in the Precambrian has been regulated by photosynthetic organisms and geological phenomena . Plants , algae and cyanobacteria use light energy to photosynthesize carbohydrate from carbon dioxide and water , with oxygen produced as a waste product .   Carbon dioxide is produced by all aerobic organisms when they metabolize carbohydrates and lipids to produce energy by respiration . It is returned to water via the gills of fish and to the air via the lungs of air-breathing land animals , including humans . Carbon dioxide is produced during the processes of decay of organic materials and the fermentation of sugars in bread , beer and winemaking . It is produced by combustion of wood and other organic materials and fossil fuels such as coal , peat , petroleum and natural gas .   It is a versatile industrial material , used , for example , as an inert gas in welding and fire extinguishers , as a pressurizing gas in air guns and oil recovery , as a chemical feedstock and in liquid form as a solvent in decaffeination of coffee and supercritical drying . It is added to drinking water and carbonated beverages including beer and sparkling wine to add effervescence . The frozen solid form of , known as `` dry ice '' is used as a refrigerant and as an abrasive in dry-ice blasting .   Carbon dioxide is the most significant long-lived greenhouse gas in Earth 's atmosphere . Since the Industrial Revolution anthropogenic emissions - primarily from use of fossil fuels and deforestation - have rapidly increased its concentration in the atmosphere , leading to global warming . Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid .

Fahrenheit <=SEP=> Fahrenheit is a temperature scale based on one proposed in 1724 by Amsterdam-based physicist Daniel Gabriel Fahrenheit ( 1686 -- 1736 ) , after whom the scale is named . It uses the degree Fahrenheit ( symbol ° F ) as the unit . Several accounts of how he originally defined his scale exist . The lower defining point , 0 ° F , was established as the temperature of a solution of brine made from equal parts of ice and salt . Further limits were established as the melting point of ice ( 32 ° F ) and his best estimate of the average human body temperature ( 96 ° F , about 2.6 ° F less than the modern value due to a later redefinition of the scale ) . The scale is now usually defined by two fixed points : the temperature at which water freezes into ice is defined as 32 ° F , and the boiling point of water is defined to be 212 ° F , a 180 ° F separation , as defined at sea level and standard atmospheric pressure .   By the end of the 20th century , Fahrenheit was used as the official temperature scale only in the United States ( including its unincorporated territories ) , its freely associated states in the Western Pacific ( Palau , the Federated States of Micronesia and the Marshall Islands ) , the Bahamas , Belize , and the Cayman Islands . All other countries in the world now use the Celsius scale , defined since 1954 by absolute zero being − 273.15 ° C and the triple point of water being at 0.01 ° C.

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 .

Scientific consensus on climate change <=SEP=> There is currently a strong scientific consensus that the Earth is warming and that this warming is mainly caused by human activities. This consensus is supported by various studies of scientists' opinions and by position statements of scientific organizations, many of which explicitly agree with the Intergovernmental Panel on Climate Change (IPCC) synthesis reports.  Nearly all actively publishing climate scientists (97–98%) support the consensus on anthropogenic climate change, and the remaining 2% of contrarian studies either cannot be replicated or contain errors.