Energy is the important material base for the human society survival and development. Fossil energy has been the main body of human energy utilization since the industrial revolution in the 1760s. With the technological breakthroughs in wind, light, water and nuclear power generation in the 20th century, new energy (broadly defined as non-fossil energy) has risen rapidly, and its pro-portion in the primary energy has been increasing continuously. Since 2000, world energy consumption has grown at an average annual rate of 2.1%. Specifically, the consumption of coal, crude oil and natural gas has been rising at an average annual rate of 2.5%, 1.2% and 2.6%, respectively. Nuclear energy has a negative growth rate of 0.18%, and new energy has a growth rate of 13.4%, far outpacing the other energy sources. The primary energy consumption in the world continues to grow, but the growth rate is slowing down, showing a general trend of: (1) The variety of energy sources has been diversified. New energy sources like wind energy, solar energy etc. have been widely developed, with an average annual growth of 21% and 50%, respectively in the past 10 years. (2) Clean utilization of traditional energy sources, including coal-based oil and gas generation, underground coal gasification, ultra-low emissions of coal power, the oil quality has been improved continuously. (3) Scale increase of clean energy, such as natural gas and new energy, has risen from 21% in 1965 to 40% in 2019. (4) Electrification of terminal energy consumption. The electrification rate increased from 15% in 2000 to 20% in 2019, and is expected to reach 36% in 2040. (5) Intelligent management of energy system, intelligent energy system will be constructed to realize multi-energy complementation, multi-network integration, two-way response and collaborative configuration. From the perspective of future energy development trend, energy used will shift from high carbon to low carbon and finally no carbon sources, and new energy will gradually enter the prime of development.

Nowadays, the world is undergoing the period of simultaneous development of fossil energy and new energy. China's energy and resource is characterized by "unlimited new energy, rich in coal but insufficient in oil and gas", which determines the transformation of China's energy production structure from current "one large and three small" dominated by coal to "three small and one large" dominated by new energy in the future, so as to achieve "energy independence" and carbon neutral by relying on new energy. Energy researchers shoulder the mission of finding more fossil energy and developing and utilizing more new energy. The energy resources in China presents the characteristics of “infinite new energy, rich coal but insufficient oil and gas”, which determines that the energy production structure in China will shift from the current structure dominated by coal to the one dominated by new energy in the future, and will rely on new energy sources to achieve "energy independence" and carbon neutrality. Fossil energy sources such as coal, oil and natural gas are the products of the interaction and co-evolution between organisms and the Earth's environment, reflecting the geobiological process of three stages from biological primary productivity to sedimentary organic matter and then to burial organic matter^[1]. In geological history, controlled by many geological events, such as the breakup of the supercontinent, the increase of atmospheric oxygen content, the global ice age, volcanic activity, sea level variation, and the ocean hypoxia, the ecosystem has experienced the evolution represented by one life explosion and five mass extinctions. The Cambrian life explosion enriched the diversity of biological species, and the mass extinctions basically or completely broke the original ecological balance of the biosphere^[2], bring about the origination and prosperity of subsequent species, and thus providing the material basis for the formation of fossil energy. More than 90% of oil and gas resources were formed in the Phanerozoic Eon, which accounts for only 10% of the Earth's evolutionary history. Therefore, starting from the biological events in the evolution of the Earth, we have sorted out the spatial and temporal relationship between the origination, prosperity and extinction of organisms and the organic-rich strata, to provide a forward perspective based on the co-evolution of organisms and the Earth for the study of fossil energy. In this context, based on the interaction and co-evolution of "Earth, energy and human", it is necessary to open up an interdisciplinary study on fossil and new energy including resources, technologies and energy development strategies, so as to provide scientific guidance for high-quality energy development under the background of a habitable Earth and carbon neutral.

The coupling effect of tectonic and volcanic activity, sea level fluctuation, abrupt climate change, atmospheric oxidation, water hypoxia, and biological extinction in geological history controls the origination, prosperity and extinction of organisms, and directly or indirectly affects the formation and distribution of organic-rich strata (Table 1). Among these factors, oxidation events, glacial- interglacial cycles, volcanic events, etc., are closely related to the deposition of organic-rich strata.

The origination of organisms has a close relationship with the oxygen content of the Earth system. The prosperity of photosynthetic organisms is controlled by the great oxidation events, which further affects the accumulation of organic matter. The Paleoproterozoic and Neoproterozoic oxidation events corresponded to the evolutions of prokaryotes to eukaryotes and unicellular organisms to multicellular organisms^[3-4], suggesting that biological evolution is closely related with oxygen content. Oxygen is the basis for the survival of eukaryotes, and increase of oxygen content is a prerequisite for the Cambrian life explosion. In the early Paleoproterozoic (2.35-2.45 Ga), the first "great oxidation event" occurred, and the atmospheric oxygen content increased from less than 0.1% of atmospheric oxygen content nowadays to 1%-15%^[5]. After that (about 18.0-0.8 Ga), the oxygen content of the Earth was relatively stable^[6-7]. The second "great oxidation event" took place in the middle and late Neoproterozoic (0.54-0.85 Ga). Around 0.52 Ga, atmospheric oxygen content rose substantially to the Phanerozoic level. As a result, early metazoans appeared, leading to the Cambrian "life explosion"^[8]. Atmospheric oxygen content has a close relationship with the type of hydrocarbon generating parent material. Anaerobic photosynthetic bacteria only developed under the condition of less than 0.1% of atmospheric oxygen content nowadays, while cyanobacteria flourished between 0.1% and 10.0%. When the oxygen content increased to 10%-100% of atmospheric oxygen content nowadays, algae increased in diversity and eukaryotic algae began to flourish. Terrestrial plants began to flourish on a large scale when oxygen content further rose to 100%-150% of atmospheric oxygen content nowadays^[6,9]. Atmospheric oxygenation controls the changes in the types of organisms, and further affects the deposition of organic-rich strata.

The prosperity of marine organisms is influenced by increased input of terrigenous debris, active nutrient circulation, and warm and suitable climate after Glacial Age, which are conducive to the accumulation of organic carbon sources. The terrestrial rocks in the Glacial Age would be destroyed by the formation and migration of glaciers, and the terrigenous input flux to ocean would increase after the Glacial Age. During the interglacial period, a large amount of nutrient released by glaciers melt and retreat would enter the ocean with the erosion of glacial meltwater, providing nutrients for algae blooms^[25]. Large-scale deep-sea deposits of evaporite and phosphorite during the interglacial period reflect that large quantities of oxidants brought by ascending ocean currents or terrigenous input participated in the recycling of organic matter. During this process, the re-release of organophosphorus would strengthen the circulation of nutrients and lead to the prosperity of organisms in the ocean^[25]. After the Glacial Age, the warm and humid climate would strengthen weathering, subsequently, a large amount of terrigenous debris and fresh water injected into the ocean, the shallow sea area could form a warm, low-salt, high-CO₂ and nutrient-rich environment in a relatively short period of time, which was conducive to the flourishing of low planktonic algae^[26]. A large set of organic-rich strata developed in the Upper Yangtze region of China after the Glacial Age, including the Cambrian Niutitang and Qiongzhusi Formations, which record the abundance of organisms and enrichment of organic matter in the interglacial period.

Biological prosperity benefits from the nutrients provided by volcanic events. The improvement of productivity by volcanic activity is mainly reflected in the following aspects: (1) Volcanic ash is rich in nutrients such as Fe, P, N, Si, Mn, which can promote the bloom of algae and other organisms and eventually improve primary productivity^[27-28]. (2) The volcanic ash is likely to react with gases such as SO₂, HCl and HF to form salt films such as sulfide and halide, which dissolve quickly in water and significantly improve the nutrient level of seawater^[29]. (3) Volcanic ash blocks sunlight from the ocean surface, causing death of organisms in the euphotic zone and enhancing burial and preservation of organic matter^[30]. (4) Volcanic ash can form clay minerals such as montmorillonite and chlorite in seawater, and the combination of clay minerals and organic matter is conducive to the adsorption, deposition and enrichment of organic matter^[31]. In 2003, the eruption of Anatahan Volcano significantly improved the surface productivity of the Pacific Ocean, and there was about 4800 km² of algae developing^[32]. In 2008, the eruption of Kasatochi Volcano triggered a phytoplankton bloom of about (1.5-2.0)×10⁶ km² in the northeast Pacific Ocean^[33]. Volcanic ash has been found in the shale of Cretaceous Qingshankou Formation and Nenjiang Formation in Songliao Basin, Triassic Yanchang Formation in Ordos Basin, Permian Lucaogou Formation in the Santanghu Basin. The Triassic Chang 7 member in in southern Ordos Basin has multiple sets of tuff and tuffaceous interbeds, which are regarded as important conditions for the development of high-quality source rock of the Chang 7 member.

Biological extinction is usually accompanied by deposition of a large amount of organic carbon, redox condition change, volcanic activity and other factors jointly control the enrichment of organic matter. The influencing factors mainly include the redox conditions at the bottom of the water body and the surface productivity of the water body, of which high primary productivity is the prerequisite for the formation of massive organic matter, and the bottom anoxic water is the basis for the preservation of organic matter^[34]. Factors such as volcanic activity, tectonic movement, sea level rise and fall associated with the extinction event will significantly affect the changes in primary productivity and redox conditions. Upper Ordovician Wufeng Formationa-Silurian Longmaxi Formation black shale deposits are closely related to the mass extinction at the end of Ordovician^[35]. The mass extinction at the end of Ordovician was accompanied by the gradual warming of global climate and the rapid rise of sea level, and sulfide anoxic water developed at the bottom of the marine shelf, which provided good conditions for the preservation of organic matter. At the same time, due to the decrease of predators, planktons such as algae and other organisms multiplied in large numbers, which greatly improved the primary productivity of the marine surface with high content of nutrient elements such as Ba, P and Zn. Therefore, a large amount of organic matter was generated, providing material basis for the development of organic-rich black shale^[34]. At the same time, multiple volcanic eruptions occurred during the mass extinction period, which not only provided abundant nutrients to the ocean, but also prevented light and exacerbated the hypoxic environment on the seafloor, promoting the deposition of organic matter^[35].

A number of major biological events occurred in the evolution history of the Earth, including one life explosion and five mass extinctions. These events have profound impact on the evolution of Earth ecosystem^[2,36] (Table 2). During this evolution, the origination, prosperity and extinction of organisms were controlled by many factors, and were closely related to the content fluctuation of organic carbon sources in the geological history. They significantly affected the formation and preservation of organic matter, and finally controlled the formation of organic-rich strata (Fig. 1). Through the analysis of the relationship between the six major biological events and the associated environmental background and ecosystem changes, the interaction and cooperative evolutions of organisms and Earth environment were examined to search the distribution laws of organic-rich strata under the background of the evolution of Earth system.

The Cambrian life explosion triggered a series of ecological effects, forming a marine ecosystem dominated by metazoans. It was the first explosive flourish of metazoan in a short geological period (at 514-541 Ma) with at least 20 metazoans and 6 extinct biogroups. A large number of biogroups occurred, including Chengjiang, Qingjiang, Meishucun, Niutitang etc. The Cambrian life explosion was stimulated by many environmental factors, but the interaction mechanisms among these factors need to be further revealed^[37]. In the Cambrian period, seafloor hydrothermal activities and upwelling ocean currents brought necessary trace elements of organisms for mass reproduction, significantly improving the primary productivity, and thus providing a material basis for the enrichment of organic matter (Fig. 1). Meanwhile, the anoxic water on the ocean bottom provided advantage conditions for the preservation of organic matter, which was conducive to the formation of shale with high organic carbon abundance. The Cambrian Qiongzhusi and Niutitang Formations in the Yangtze Plateau have 50-600 m thick black shale strata developing, with a distribution area of more than 90×10⁴ km², TOC contents from 0.5% to 9.0%, and R_o values between 1% and 5% (over-mature stage), these shale strata are important shale gas exploration targets in Southern China^[38]. The Cambrian organic-rich shale strata are widespread in many regions in the world, such as Alum shale in Europe, Arthur shale in Australia, and Olenyok oil shale in Russia etc.

The mass extinction taking place at the turn between Ordovician and Silurian was closely associated with many controlling factors including climate change, glacier development and sea level eustacy, leading to the extinction of about 61% biological genuses and 86% biological species. The mass extinction can be divided into two stages. The first stage occurred from Late Cady to early Hernant, whereas the second stage took place in the late Hernant^[2,58]. The timing of the first stage matches well with the beginning of the Hernant Glacial Age^[2]. During this stage, the climate turned cold sharply, and the sea level fell rapidly. Meanwhile, the ocean water was rich in oxygen, and the deep ocean currents were active^[59]. The second stage started at the beginning of Late Hernant. During this stage, the global climate turned warm rapidly, so Gondwana ice sheet melted, the sea level rose rapidly, and the shallow water on the seafloor was anoxic with stagnation of the ocean current cycle, resulting in large-scale extinction of cold water organisms^[60]. The frequent transformation between greenhouse and icehouse caused by changes in paleotemperature is the most important controlling factor for this mass extinction^[36]. At the turn between Ordovician and Silurian, a large number of graptolites flourished, and black shale with rich organic matters widely deposited in the world, forming the most important shale gas exploration strata in Southern China. Worldwide, the black shales formed at the turn between Ordovician and Silurian are widely distributed, including Llandovery shale in Europe, Godwyer shale in Australia, and Tannezuft shale in Africa. The 300 m thick black shale in the Silurian Wufeng-Longmaxi Formation in Southern China is abundant in shale gas. The “sweet spot” layer is located at the bottom of the Longmaxi Formation, with a thickness of 10-60 m, TOC values from 0.4% to 9.6%, R_o values between 2.3% and 3.8% (indicating overmature dry gas stage). This set of shale gives rise to a large number of shale gas provinces, including Weiyuan area, Changning-Zhaotong area and Fuling area. These shale gas provinces had annual shale gas production of 154×10⁸ m³ in 2019, making Wufeng- Longmaxi Formation shale in southern China the second largest shale gas production province in the world^[34].

The mass extinction at the turn between the Frasnian and Famennian (F-F) period of the Late Devonian led to the die-off of at least 75% of the species, and the community structure changed significantly, profoundly changing the evolution of life on Earth. Large-scale volcanism on Russian platform and Siberian plate at the Late Devonian might be the inducing factor of dramatic changes in climate environment, which led to the rapid cooling of global climate in F-F period, hypoxia in shallow sea area, frequent sea level fluctuation, etc., triggering the mass extinction of organisms in F-F period^[42]. During this period, the sea water was obviously stratified, and the hypoxic water diffused to shallow water areas, leading to the hypoxia of the continental shelf, increase of buried organic carbon, resulting in the decrease of atmospheric CO₂ partial pressure and the rapid cooling of the global climate. Many evidences show that global hypoxia occurs in F-F period, including enrichment of framboid pyrite^[61-62], abnormal abundance of redox sensitive elements (U, Mo, V, Ce, etc.)^[63], negative excursion of U isotope (²³⁸U/²³⁵U value)^[64], two significant positive excursions of carbon isotope, and anomaly of sulfur isotope^[60]. The flourish and extinction of organisms in F-F period provided abundant material basis for the deposition of organic matter. The environmental conditions such as sea level rise and anoxic events were favorable for the burial and preservation of sedimentary organic matter. In the Late Devonian, a large number of organic-rich shales, such as the Bakken, Marcellus and Woodford shales in North America, the Frasnian shale in Africa, and the Rudov Bed shale in Europe, developed worldwide, making the Late Devonian to Early Carboniferous one of the six major hydrocarbon accumulation periods in the world^[65]. Marine Bakken Shale in Willis Basin, USA, is one of the earliest industrial shale oil and gas production area in North America, where the Bakken shale at the burial depths of 2590 to 3200 m has an oil bearing area of 7×10⁴ km², TOC values from 11% to 20%, mainly type II kerogen, R_o values of 0.7%-1.0%, and an average oil saturation of 68%. From the Late Silurian to the Early and Middle Devonian, herbaceous psilophytes extended to the land, forming coal lines or thin coal seams. In the Late Devonian, psilophytes basically disappeared, while new plant types dominated by lycophylla, cuneifolia, seed ferns, etc., proliferated rapidly, and more xylophytas appeared, giving rise to thin layers or lentiform distributed humus coal systems^[66].

The largest mass extinction event since the Phanerozoic happened at the turn of the Permian and Triassic periods. In this event, about 90% of marine and 70% of terrestrial organisms died off, changing the surface ecosystem dramatically. This mass extinction took place at the important geological transition period from Paleozoic to Mesozoic, when the Earth underwent major environmental events such as supercontinent convergence, super volcanic eruption, sea level fluctuations, ocean hypoxia, and temperature fluctuations^[67]. Factors triggering the mass extinction factors included an asteroid impact, volcanic eruption, fall of sea level, ocean hypoxia, high temperature and acidification events, etc.^[36]. Among them, the Siberian igneous rocks developed with a large amount of CO₂ release, frequent wildfires on land, ocean circulation stagnation, ocean acidification and hypoxia, a dramatic rise in temperature have strong correlation with this mass extinction^[2,68]. From the Carboniferous to the Permian to the Triassic, the Earth underwent a transition from icehouse to greenhouse climate, and the replacement and migration of Marine and terrestrial plants^[69]. Consequently, Permian has become one of the most important organic-rich strata in the world. By the end of 2018, the Permian Basin in the United States had recoverable oil and gas reserves of 119×10⁸ t and 8.5×10¹² m³ respectively proved^[24]. During this period, South and North China were located in the Paleo-Tethys island ocean system, and a complete set of Permian strata were deposited. The Upper Permian Longtan Formation in Sichuan Basin has organic-rich shale more than 40 m thick. With moderate thermal evolution degree, and good gas-bearing property, this set of shale has substantial exploration and development potential. The eastern margin of Ordos Basin in North China has organic-rich coal measures and transitional shales developing in Permian. The lower member of Shanxi Formation tested stable gas production, showing huge exploration and development potential. The Carboniferous to Permian was the first large coal accumulation period in the world, when the swamp forest dominated by lycopods was the main coal forming environment.

The mass extinction at the turn between the Triassic and Jurassic wiped out about 52% of genera and 76% of species in marine ecosystems, reflecting the response of ecosystems to climate change in the context of greenhouse climate. A series of major global tectonic and climate changes took place in the Late Triassic, including the breakup of Pangaea, the closure of the Paleo-Tetthys Ocean, the volcanic eruption of the Middle Atlantic, and the Carnian moist event, etc.^[70-71]. Atmospheric CO₂ content in the Late Triassic reached the highest level in the Mesozoic^[45], while O₂ content was at the lowest level^[72]. This period witnessed complex and variable palaeo-environment, sharp sea level fluctuations, and frequent palaeo-tectonic activities^[73]. Frequent volcanic activities led to the increase of CO₂ and CH₄ concentration, subsequently, the strong greenhouse effect caused frequent occurrence of extreme climate, which destroyed the terrestrial ecosystem, and then led to the strengthening of water cycle and surface weathering, sharp increase of terrestrial input, and finally the collapse of the marine ecosystem^[74]. Before and after the extinction, extreme climate events occurred frequently, and the anoxic event resulted in environmental conditions conducive for the deposition of widely distributed organic-rich black shale. During the Late Triassic, the greenhouse climate represented by that in the Carney period occurred, and organic-rich black shales were widely deposited in the Palaeo-Tethys continental shelf area, including the Montney shale in Canada, the Emm shale in Europe, and the Kockatea shale in Australia.

The mass extinction in the late Cretaceous was induced by astrophysical impact and volcanic eruption, in which approximately 16% family and 47% genuses of marine organisms perished. The celestial body collision^[75] and large-scale volcanic eruptions^[76] led to increase of CO₂in atmospheric and frequent acid rains, volcanic ash, and deteriorating ecological environment. Consequently, the biological photosynthesis was hindered, and the diversity of marine invertebrates and vertebrates decreased substantially^[77-78]. This extinction event is marked by the iridium-rich clay layer containing impacted quartz, tektite and nickel-rich spinel, with obvious negative excursion of carbon isotope values^[54]. Cretaceous-Paleogene period witnessed dramatic change in climate and environment conditions and accelerated biological replacement rate. The mass extinction corresponded to deposition of organic-rich black shales. The organic-rich strata formed under anoxic environment in the Middle Cretaceous period are the most important hydrocarbon source rocks globally^[79], including the shales in the Cretaceous Quantou-Qingshankou Formations in the Songliao Basin, Eagle Ford shale and Niobrara shale in the US. After this mass extinction, the ecological environment gradually recovered, and new species flourished in the Paleogene. In the depositional period of the second and third members of Paleogene Kongdian Formation in Early Paleogene, the biological species increased rapidly, and black shale deposited in multiple depressions in the Bohai Bay Basin. Among them, the second member of Kongdian Formation in the Cangdong Sag, Huanghua Depression has an average TOC value of 3.26%, mainly type I and type II₁organic matter, the R_o values between 0.50% and 0.92%, and source rocks of 400 m in maximum thickness. The Jurassic and Cretaceous period prior to this mass extinction is the second largest coal forming period in the world, when thick layers of coal seam were deposited in Xinjiang, Northern Shaanxi, Inner Mongolia and Northeast China^[70].

The formation of organic-rich strata is the combined result of multiple factors including biological events, climate events and geological events. It is also the product of the interaction of complex systems in geological history period including atmosphere, hydrosphere, lithosphere, biosphere and astronomical cycle^[80]. The birth and development of Earth system science^[81-82] laid a scientific theoretical foundation for studying the formation rules of organic-rich strata and investigating the relationship between human activities and energy development.

Since the Earth was formed -4.6 Ga, the Sun has been the fundamental driving force for Earth system evolution^[82]. The paleo-ocean formed at -4.4 Ga, where the CH₄, ammonia, CO₂, water vapor and other substances in the primitive atmosphere provided basic conditions for nurturing life. Then prokaryotes appeared around 3.5-3.8 Ga, representing the appearance of life on Earth, which provided the basis for the formation of subsequent fossil energy. Eventually the hominid was born about 6 Ma, starting a new era in energy utilization. With the progress of human society, fuel wood, coal, oil and gas have iteratively become the main energy forms. Currently, we are at a new stage transitioning from fossil energy to new energy^[83] (Fig. 2).

Humans are adapting and reconstructing the environment of the Earth at unprecedented intensity, and its influence is larger than ever before. We now live in the Anthropocene^[84], underlining the central role of human activities in geology and environment. Today, human society has entered the sixth scientific and technological revolution and the fourth industrial revolution. Science and technology have endowed us with more ability to use and transform natural world, and are playing a dominant role in the direction of energy development. The energy used has turned from high carbon energy to low carbon and then carbon-free energy. Now the resource-based "exploiting energy" is gradually replaced by technology-based "creating energy". In the future, it is expected to enter the era of artificial energy represented by artificially controlled nuclear fusion. In the Anthropocene era, it is necessary to establish a systematic energy discipline studying the past and present of the Earth, the formation and evolution of energy, as well as human behavior and ability.

The development of Earth Science has gone through the process from disciplines subdivision to disciplines combination, forming Earth system science^[82]. So does the energy research. Currently, energy studies usually start from the perspective of resource utilization and are divided into more and more detailed disciplines, such as coalfield geology, oil and gas geology, unconventional oil and gas geology, and new energy etc. These disciplines have laid a theoretical foundation for revealing the nature, exploring the evolution law, and guiding the development direction of energy. However, these disciplines usually focus on the formation, evolution, distribution, accumulation and utilization of a single energy type, and have not yet comprehensively considered the interaction and co-evolution of the Earth, energy and human beings on different spatial and temporal scales from the perspective of Earth evolution within the framework of the Earth system.

The birth of human beings has opened the era of energy utilization. With natural resources existing objectively, human activities must develop and exploit energy. Since industrialization, fossil energy has always been the main resource, providing a sustained driving force for the development of human society. However, resource depletion, environmental pollution, global warming, and energy equity etc. have posed new challenges to energy development and restricted the harmonious survival and development of human beings and the Earth's environment. Energy is an important part of the construction of a "habitable Earth". Based on the development of human society, it is necessary to turn the consideration of energy economy in the past to the consideration of effect of energy to Earth habitability. We must break through the traditional fossil energy category and expand to clean and efficient new energy. Therefore, from the perspective of the evolution of the Earth system, it is necessary to explore the multiple relationships between energy and the Earth, energy and environment, energy and human beings, and carry out comprehensive research on energy science.

Energy has two utilization attributes: one is to obtain energy by transforming naturally forming or artificially developed energy-carrying substances, the other is to obtain material products by using natural resources as raw materials for chemical or industrial production. Therefore, from the perspective of energy acquisition, energy refers to the total of natural substances formed by the evolution of the Earth system or from the space which can be processed and utilized by human beings to obtain energy.

According to occurrence space on the Earth, energy could be divided into underground, surface and extraterrestrial energy, including: (1) traditional fossil energy such as coal, oil and natural gas from shallow biogenic strata and nuclear energy such as uranium and thorium from inorganic origin, as well as geothermal energy and inorganic gas from deep underground fluid action; (2) wind energy, tidal energy and water energy from geological forces in the surface system; (3) solar energy in the system of extraterrestrial bodies.

According to the material composition, it can be divided into carbon energy, hydrogen energy and others. Carbon-based energy refers to the natural resources formed or derived from carbon-based substances that can be converted into energy and release CO₂, usually including coal, oil, natural gas, and biomass energy etc. Hydrogen energy refers to the energy converted from hydrogen-containing materials (such as water energy, and tidal energy, etc.) or directly released by hydrogen nuclear physical reaction (solar energy, and nuclear fusion energy, etc.) or indirectly driven energy (wind energy, and geothermal energy, etc.). Other sources of energy are the energy produced by nuclear fission reactions of materials (such as uranium and thorium) that contain neither carbon nor hydrogen.

The energy science is a discipline that studies the formation and distribution, evaluation and selection, development and utilization, orderly replacement, and development prospects of all kinds of energy resources at the time and space scales based on the evolution of the Earth system. The core of energy science is to study the interaction and co-evolution of the Earth, energy and human beings. The connotation of energy science includes three core contents: (1) The formation of energy under the background of the Earth system and the feedback of energy consumption to the Earth's climate environment, which reflect the relationship between the Earth and energy. (2) The Earth environment breeds human evolution, while human behavior transforms the Earth environment, reflecting the relationship between the Earth and human beings. (3) Human use technology to develop energy, while energy drives human social progress, reflecting the relationship between human and energy. The research purpose of energy science is to reveal the symbiotic distribution relationship between fossil energy and non-fossil new energy, orderly replacement and transformation of carbon and hydrogen energy, and the law of green and harmonious development between energy system and habitable Earth from the perspective of resources.

The research objects of energy science are not completely limited to the fossil energy developed in the ground, but extend to the surface system energy (such as water energy, wind energy, tidal energy, etc.), and extend from carbon energy to hydrogen energy. The research is not completely limited to reveal the biological evolution, organic matter deposition and material cycle related to the formation and distribution of fossil energy in geological history, but reveal the past formation law, present distribution law and future development law of energy from the perspective of Earth evolution history, energy formation history and human development history.

Energy research focuses on four aspects, including the formation and development of fossil energy, the development and orderly replacement of new energy sources, the exploration and utilization of deep-earth and deep-space energy sources, and the strategy and planning of energy development. Specifically, (1) The formation and development of fossil energy are to study the evolution law of biological remains deposited and buried in the shallow crust in geological history, which reflects the co-evolution of the effect of the earth's environment on organisms and the modification of biological behavior on environment. (2) The development and orderly replacement of new energy studies non-fossil energy such as wind, light, water, geothermal and nuclear energy generated by geological or human forces in the earth surface system, reflecting the interaction between technology of natural resources transformation and energy-driven human activities. (3) The exploration and utilization of deep earth and deep space energy study on the origin, resource potential and effective utilization of deep energy related to the mantle and the Earth core, as well as the exploration of extraterrestrial energy, reflecting the human efforts to explore the deep earth and the deep space. (4) Energy development strategy and planning are to study all kinds of energy utilization planning, transformation development layout and energy structure optimization in the earth system, reflecting the development requirements of building a clean and efficient energy system and constructing a "green home and a habitable Earth" under the constraints of climate change and carbon emission reduction and carbon neutral.

The energy science is of great significance for improving the discipline system, promoting energy development, clarifying the direction of energy transformation, driving the carbon neutral geology research and building a habitable Earth: (1) From the perspective of the evolution of the earth system, it perfects the energy disciplines divided according to single energy types, reveals the law of energy development from systematic evolution angle, and is of great significance for improving the structure of energy disciplines. (2) Following the shift from fossil energy to non-fossil energy, it focuses on the development and utilization of surface, underground and extraterrestrial energy, and will promote the development of energy to low-carbon and clean energy sources. (3) Based on the history of energy utilization, it is pointed out that the energy we used follows a shift trend from high carbon to low carbon and carbon free energy, the common development of fossil energy and new energy should be strengthened, so this discipline is of strategic significance for speeding up the shift of energy type and path. (4) Focusing on deep-time and modern carbon cycle processes, it studies the mechanisms and processes of sedimentology and geochemistry from carbon sources to carbon sinks is of forward-looking significance for promoting the development of carbon neutral geology; (5) Exploring the relationship between the "Earth, energy and human beings" at different time and space scales can guide the sustainable development and utilization of the Earth's energy, the clean and green development and the construction of a habitable Earth.

Major biological events have significant controlling effect on the evolution of the Earth's ecosystem, which further controls the prosperity and extinction of the organism. The two intertwine in complex ways, and evolve in spiral pattern, forming multiple sets of organic-rich strata correspondingly, which contain abundant fossil energy (e.g. hydrocarbon source rocks and coal). The six major biological events happened in geological history only represent the key periods of the biological evolution of the Earth. The origination, prosperity and extinction of organisms are the manifestation forms of biological events. Both life explosion and continuation of species after extinction provide the material basis for the formation of fossil energy, so the formation and distribution of fossil energy are closely related to biological events. The investigation of biological events is the key to revealing the deep time geological processes and the formation of fossil energy. Fossil energy provides not only energy for human activities, but also important raw materials for chemical industry, which will still play an important role in future social development.

From the perspective of the evolution of the Earth system, this paper puts forward the concept of energy science studying the relationships between energy and the Earth, energy and environment, and energy and human. Grounded on the evolution of Earth system, the energy science studies the formation, distribution, evaluation, selection, exploitation and utilization, orderly replacement and development prospects of various energy sources from different time and space scales. The connotations of energy science include: (1) the formation process of energy and the relationship between energy consumption and the climate environment of the Earth under the background of the Earth system; (2) the relationship between earth environment and human beings, the transformation of earth environment by human behavior, and the relationship between the Earth and human beings; (3) Three core contents of the energy utilization and development technology, the promotion of energy to human social progress, and the relationship between human and energy. Energy science research focuses on four aspects: formation and development of fossil energy, development and orderly replacement of new energy, exploration and utilization of energy in deep Earth and deep space, and energy development strategy and planning. The proposal of energy science is of great significance for improving the discipline system, promoting development of energy and carbon neutral, defining the direction of energy development and constructing a habitable Earth.

The proposal of energy science is grounded on the continuous development of Earth ecosystem and science and technology. In different periods of the future, as the main energy type changes, the questions we concern will change accordingly, and the energy science based on Earth, energy and human being will evolve and develop inevitably.