The prospect of natural gas hydrate(NGH)under the vision of Peak Carbon Dioxide Emissions in China

To achieve the goals of Peak Carbon Dioxide Emissions and Carbon Neutrality,China's energy system will continue to accelerate the transition to a clean and low-carbon one.As the cleanest fossil fuel,natural gas is regarded as an inevitable choice for China to build a clean,safe,efficient,and low-carbon energy system and fulfill the goal of“double carbon”.However,the domestic conventional natural gas supply remains rigid while the stimulation of unconventional natural gas is still limited.If we have a firm grip on the principal line of“understanding the ocean–developing resources–ensuring security”to realize the large-scale development of 85 trillion square meters of NGH in the South China Sea,then we could not only greatly reduce China‘s foreign dependence on natural gas,but also guarantee the safety of China‘s natural gas multi-path supply and safeguard the sovereignty of the South China Sea.Thus,the goal of Peak Carbon Dioxide Emissions and Carbon Neutrality can be achieved in no time.

Change trend of natural gas hydrates in permafrost on the Qinghai-Tibet Plateau(1960-2050)under the background of global warming and their impacts on carbon emissions

Global warming and the response to it have become a topic of concern in today’s society and are also a research focus in the global scientific community.As the world’s third pole,the global warming amplifier,and the starting region of China’s climate change,the Qinghai-Tibet Plateau is extremely sensitive to climate change.The permafrost on the Qinghai-Tibet Plateau is rich in natural gas hydrates(NGHs)resources.Under the background of global warming,whether the NGHs will be disassociated and enter the atmosphere as the air temperature rises has become a major concern of both the public and the scientific community.Given this,this study reviewed the trend of global warming and accordingly summarized the characteristics of the temperature increase in the Qinghai-Tibet Plateau.Based on this as well as the distribution characteristics of the NGHs in the permafrost on the Qinghai-Tibet Plateau,this study investigated the changes in the response of the NGHs to global warming,aiming to clarify the impacts of global warming on the NGHs in the permafrost of the plateau.A noticeable response to global warming has been observed in the Qinghai-Tibet Plateau.Over the past decades,the increase in the mean annual air temperature of the plateau was increasingly high and more recently.Specifically,the mean annual air temperature of the plateau changed at a rate of approximately 0.308-0.420℃/10a and increased by approximately 1.54-2.10℃in the past decades.Moreover,the annual mean ground temperature of the shallow permafrost on the plateau increased by approximately 1.155-1.575℃and the permafrost area decreased by approximately 0.34×10^(6)km^(2) from about 1.4×10^(6)km^(2) to 1.06×10^(6)km^(2) in the past decades.As indicated by simulated calculation results,the thickness of the NGH-bearing permafrost on the Qinghai-Tibet Plateau has decreased by 29-39 m in the past 50 years,with the equivalent of(1.69-2.27)×10^(10)-(1.12-1.51)×10^(12)m^(3) of methane(CH_(4))being released due to NGHs dissociation.It is predicted that the thickness of the NGH-bearing permafrost will decrease by 23 m and 27 m,and dissociated and released NGHs will be the equivalent of(1.34-88.8)×10^(10)m^(3) and(1.57-104)×10^(10)m^(3)of CH_(4),respectively by 2030 and 2050.Considering the positive feedback mechanism of NGHs on global warming and the fact that CH_(4) has a higher greenhouse effect than carbon dioxide,the NGHs in the permafrost on the Qinghai-Tibet Plateau will emit more CH_(4) into the atmosphere,which is an important trend of NGHs under the background of global warming.Therefore,the NGHs are destructive as a time bomb and may lead to a waste of efforts that mankind has made in carbon emission reduction and carbon neutrality.Accordingly,this study suggests that human beings should make more efforts to conduct the exploration and exploitation of the NGHs in the permafrost of the Qinghai-Tibet Plateau,accelerate research on the techniques and equipment for NGHs extraction,storage,and transportation,and exploit the permafrost-associated NGHs while thawing them.The purpose is to reduce carbon emissions into the atmosphere and mitigate the atmospheric greenhouse effect,thus contributing to the global goal of peak carbon dioxide emissions and carbon neutrality.

Progress, challenge and significance of building a carbon industry system in the context of carbon neutrality strategy

Carbon dioxide storage and utilization has become an inevitable trend and choice for sustainable development under the background of global climate change and carbon neutrality.Carbon industry which is dominated by CO_(2) capture,utilization and storage/CO_(2) capture and storage(CCUS/CCS)is becoming a new strategic industry under the goal of carbon neutrality.The sustainable development of carbon industry needs to learn from the experiences of global oil and gas industry development.There are three types of“carbon”in the earth system.Black carbon is the CO_(2) that has not been sequestered or used and remains in the atmosphere for a long time;grey carbon is the CO_(2) that has been fixed or permanently sequestered in the geological body,and blue carbon is the CO_(2) that could be converted into products for human use through biological,physical,chemical and other ways.The carbon industry system covers carbon generation,carbon capture,carbon transportation,carbon utilization,carbon sequestration,carbon products,carbon finance,and other businesses.It is a revolutionary industrial field to completely eliminate“black carbon”.The development of carbon industry technical system takes carbon emission reduction,zero carbon,negative carbon and carbon economy as the connotation,and the construction of a low-cost and energy-efficient carbon industry system based on CCUS/CCS are strategic measures to achieve the goal of carbon neutrality and clean energy utilization globally.This will promote the“four 80%s”transformation of China's energy supply,namely,to 2060,the percentage of zero-carbon new energy in the energy consumption will be over 80%and the CO_(2) emission will be decreased by 80%to ensure the carbon emission reduction of total 80×10^(8) t from the percentage of carbon-based fossil energy in the energy consumption of over 80%,and the percentage of CO_(2) emission from energy of over 80%in 2021.The carbon industry in China is facing three challenges,large CO_(2) emissions,high percentage of coal in energy consumption,and poor innovative system.Three strategic measures are proposed accordingly,including:(1)unswervingly develop carbon industrial system and ensure the achievement of carbon neutrality as scheduled by 2060;(2)vigorously develop new energy sources and promote a revolutionary transformation of China’s energy production and consumption structure;(3)accelerate the establishment of scientific and technological innovation system of the whole CO_(2) industry.It is of great significance for continuously optimization of ecological environment and construction of green earth and ecological earth to develop the carbon industry system,utilize clean energy,and achieve the strategic goal of global carbon neutrality.

The role of new energy in carbon neutral

Carbon dioxide is an important medium of the global carbon cycle,and has the dual properties of realizing the conversion of organic matter in the ecosystem and causing the greenhouse effect.The fixed or available carbon dioxide in the atmosphere is defined as"gray carbon",while the carbon dioxide that cannot be fixed or used and remains in the atmosphere is called"black carbon".Carbon neutral is the consensus of human development,but its implementation still faces many challenges in politics,resources,technology,market,and energy structure,etc.It is proposed that carbon replacement,carbon emission reduction,carbon sequestration,and carbon cycle are the four main approaches to achieve carbon neutral,among which carbon replacement is the backbone.New energy has become the leading role of the third energy conversion and will dominate carbon neutral in the future.Nowadays,solar energy,wind energy,hydropower,nuclear energy and hydrogen energy are the main forces of new energy,helping the power sector to achieve low carbon emissions."Green hydrogen"is the reserve force of new energy,helping further reduce carbon emissions in industrial and transportation fields.Artificial carbon conversion technology is a bridge connecting new energy and fossil energy,effectively reducing the carbon emissions of fossil energy.It is predicted that the peak value of China’s carbon dioxide emissions will reach 110×10^(8) t in 2030.The study predicts that China’s carbon emissions will drop to 22×10^(8) t,33×10^(8) t and 44×10^(8) t,respectively,in 2060 according to three scenarios of high,medium,and low levels.To realize carbon neutral in China,seven implementation suggestions have been put forward to build a new"three small and one large"energy structure in China and promote the realization of China’s energy independence strategy.