Query: The trend in CO2 at Mauna Loa is practically identical to the global trend because CO2 mixes well throughout the atmosphere.

Relevant passages:
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 .

Greenhouse gas <=SEP=> A greenhouse gas ( abbrev . GHG ) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range . This process is the fundamental cause of the greenhouse effect . The primary greenhouse gases in Earth 's atmosphere are water vapor , carbon dioxide , methane , nitrous oxide , and ozone . Without greenhouse gases , the average temperature of Earth 's surface would be about -18 ° C , rather than the present average of 15 ° C . In the Solar System , the atmospheres of Venus , Mars and Titan also contain gases that cause a greenhouse effect .   Human activities since the beginning of the Industrial Revolution ( taken as the year 1750 ) have produced a 40 % increase in the atmospheric concentration of carbon dioxide , from 280 ppm in 1750 to 406 ppm in early 2017 . This increase has occurred despite the uptake of a large portion of the emissions by various natural `` sinks '' involved in the carbon cycle . Anthropogenic carbon dioxide emissions ( i.e. , emissions produced by human activities ) come from combustion of fossil fuels , principally coal , oil , and natural gas , along with deforestation , soil erosion and animal agriculture .   It has been estimated that if greenhouse gas emissions continue at the present rate , Earth 's surface temperature could exceed historical values as early as 2047 , with potentially harmful effects on ecosystems , biodiversity and the livelihoods of people worldwide . Recent estimates suggest that on the current emissions trajectory the Earth could pass a threshold of 2 ° C global warming , which the United Nations ' IPCC designated as the upper limit to avoid `` dangerous '' global warming , by 2036 .

Carbon dioxide in Earth's atmosphere <=SEP=> Carbon dioxide is an important trace gas in Earth 's atmosphere . Currently it constitutes about 0.041 % ( equal to 410 parts per million ; ppm ) by volume of the atmosphere . Despite its relatively small concentration is a potent greenhouse gas and plays a vital role in regulating Earth 's surface temperature through radiative forcing and the greenhouse effect . Reconstructions show that concentrations of in the atmosphere have varied , ranging from as high as 7,000 ppm during the Cambrian period about 500 million years ago to as low as 180 ppm during the Quaternary glaciation of the last two million years .   Carbon dioxide is an integral part of the carbon cycle , a biogeochemical cycle in which carbon is exchanged between the Earth 's oceans , soil , rocks and the biosphere . Plants and other photoautotrophs use solar energy to produce carbohydrate from atmospheric carbon dioxide and water by photosynthesis . Almost all other organisms depend on carbohydrate derived from photosynthesis as their primary source of energy and carbon compounds .   The current episode of global warming is attributed to increasing emissions of and other greenhouse gases into Earth 's atmosphere . The global annual mean concentration of in the atmosphere has increased by more than 40 % since the start of the Industrial Revolution , from 280 ppm , the level it had for the last 10,000 years leading up to the mid-18th century , to 399 ppm as of 2015 . The present concentration is the highest in at least the past 800,000 years and likely the highest in the past 20 million years . The increase has been caused by anthropogenic sources , particularly the burning of fossil fuels and deforestation . The daily average concentration of atmospheric CO2 at Mauna Loa Observatory first exceeded 400 ppm on 10 May 2013 . It is currently rising at a rate of approximately 2 ppm/year and accelerating . An estimated 30 -- 40 % of the released by humans into the atmosphere dissolves into oceans , rivers and lakes , which contributes to ocean acidification .

Ecosystem ecology <=SEP=> Ecosystem ecology is the integrated study of living ( biotic ) and non-living ( abiotic ) components of ecosystems and their interactions within an ecosystem framework . This science examines how ecosystems work and relates this to their components such as chemicals , bedrock , soil , plants , and animals .   Ecosystem ecology examines physical and biological structures and examines how these ecosystem characteristics interact with each other . Ultimately , this helps us understand how to maintain high quality water and economically viable commodity production . A major focus of ecosystem ecology is on functional processes , ecological mechanisms that maintain the structure and services produced by ecosystems . These include primary productivity ( production of biomass ) , decomposition , and trophic interactions .   Studies of ecosystem function have greatly improved human understanding of sustainable production of forage , fiber , fuel , and provision of water . Functional processes are mediated by regional-to-local level climate , disturbance , and management . Thus ecosystem ecology provides a powerful framework for identifying ecological mechanisms that interact with global environmental problems , especially global warming and degradation of surface water .   This example demonstrates several important aspects of ecosystems :  Ecosystem boundaries are often nebulous and may fluctuate in time  Organisms within ecosystems are dependent on ecosystem level biological and physical processes  Adjacent ecosystems closely interact and often are interdependent for maintenance of community structure and functional processes that maintain productivity and biodiversity   These characteristics also introduce practical problems into natural resource management . Who will manage which ecosystem ? Will timber cutting in the forest degrade recreational fishing in the stream ? These questions are difficult for land managers to address while the boundary between ecosystems remains unclear ; even though decisions in one ecosystem will affect the other . We need better understanding of the interactions and interdependencies of these ecosystems and the processes that maintain them before we can begin to address these questions .   Ecosystem ecology is an inherently interdisciplinary field of study . An individual ecosystem is composed of populations of organisms , interacting within communities , and contributing to the cycling of nutrients and the flow of energy . The ecosystem is the principal unit of study in ecosystem ecology .   Population , community , and physiological ecology provide many of the underlying biological mechanisms influencing ecosystems and the processes they maintain . Flowing of energy and cycling of matter at the ecosystem level are often examined in ecosystem ecology , but , as a whole , this science is defined more by subject matter than by scale . Ecosystem ecology approaches organisms and abiotic pools of energy and nutrients as an integrated system which distinguishes it from associated sciences such as biogeochemistry .   Biogeochemistry and hydrology focus on several fundamental ecosystem processes such as biologically mediated chemical cycling of nutrients and physical-biological cycling of water . Ecosystem ecology forms the mechanistic basis for regional or global processes encompassed by landscape-to-regional hydrology , global biogeochemistry , and earth system science .