The environmental effects of bitcoin are significant. Bitcoin mining, the process by which bitcoins are created and transactions are finalized, is energy-consuming and results in carbon emissions, as about half of the electricity used is generated through fossil fuels. [1] Moreover, bitcoins are mined on specialized computer hardware with a short lifespan, resulting in electronic waste. [2] The amount of e-waste generated by bitcoin mining is comparable to that generated by the Netherlands. [2] Scholars argue that bitcoin mining could support renewable energy development by utilizing surplus electricity from wind and solar. [3] Bitcoin's environmental impact has attracted the attention of regulators, leading to incentives or restrictions in various jurisdictions. [4]
Bitcoin mining is a highly electricity-intensive proof-of-work process. [1] [5] Miners run dedicated software to compete against each other and be the first to solve the current 10 minute block, yielding them a reward in bitcoins. [6] A transition to the proof-of-stake protocol, which has better energy efficiency, has been described as a sustainable alternative to bitcoin's scheme and as a potential solution to its environmental issues. [5] Bitcoin advocates oppose such a change, arguing that proof of work is needed to secure the network. [7]
Bitcoin mining's distribution makes it difficult for researchers to identify the location of miners and electricity use. It is therefore difficult to translate energy consumption into carbon emissions. [8] As of 2022 [update] , a non-peer-reviewed study by the Cambridge Centre for Alternative Finance (CCAF) estimated that bitcoin consumed 95.5 TWh (344 PJ ) annually, representing 0.4% of the world's electricity consumption, ranking bitcoin mining between Belgium and the Netherlands in terms of electricity consumption. [8] A 2022 non-peer-reviewed commentary published in Joule estimated that bitcoin mining resulted in annual carbon emission of 65 Mt CO2, representing 0.2% of global emissions, which is comparable to the level of emissions of Greece. [9] A 2024 systematic review criticized the underlying assumptions of these estimates, arguing that the authors relied on old and partial data. [10]
Until 2021, most bitcoin mining was done in China. [6] Chinese miners relied on cheap coal power in Xinjiang and Inner Mongolia during late autumn, winter and spring, migrating to regions with overcapacities in low-cost hydropower (like Sichuan and Yunnan) between May and October. [9] After China banned bitcoin mining in June 2021, its mining operations moved to other countries. [6] By August 2021, mining was concentrated in the U.S. (35%), Kazakhstan (18%), and Russia (11%) instead. [11] A study in Scientific Reports found that from 2016 to 2021, each US dollar worth of mined bitcoin caused 35 cents worth of climate damage, compared to 95 for coal, 41 for gasoline, 33 for beef, and 4 for gold mining. [12] The shift from coal resources in China to coal resources in Kazakhstan increased bitcoin's carbon footprint, as Kazakhstani coal plants use hard coal, which has the highest carbon content of all coal types. [9] Despite the ban, covert mining operations gradually came back to China, reaching 21% of global hashrate as of 2022 [update] . [13]
Reducing the environmental impact of bitcoin is possible by mining only using clean electricity sources. [14] In 2023, Jamie Coutts, a crypto analyst writing for Bloomberg Terminal said that renewables represented about half of global bitcoin mining sources, [15] while research by the nonprofit tech company WattTime estimated that US miners consumed 54% fossil fuel-generated power. [7] Experts and government authorities, such as the European Securities and Markets Authority and the European Central Bank, have suggested that using renewable energy for mining may limit the availability of clean energy for the general population. [1] [16] [17]
Bitcoin mining representatives argue that their industry creates opportunities for wind and solar companies, [18] leading to a debate on whether bitcoin could be an ESG investment. [19] According to a 2023 ACS Sustainable Chemistry & Engineering paper, directing the surplus electricity from intermittent renewable energy sources such as wind and solar, to bitcoin mining could reduce electricity curtailment, balance the electrical grid, and increase the profitability of renewable energy plants—therefore accelerating the transition to sustainable energy and decreasing bitcoin's carbon footprint. [20] A 2023 review published in Resource and Energy Economics also concluded that bitcoin mining could increase renewable capacity but that it might increase carbon emissions and that mining bitcoin to provide demand response largely mitigated its environmental impact. [21] Two studies from 2023 and 2024 led by Fengqi You concluded that mining bitcoin off-grid during the precommercial phase (when a wind or solar farm is generating electricity but not yet integrated into the grid) could bring additional profits and therefore support renewable energy development and mitigate climate change. [3] [22] Another 2024 study by Fengqi You published in the Proceedings of the National Academy of Sciences of the United States of America showed that pairing green hydrogen infrastructure with Bitcoin mining can accelerate the deployment of solar and wind power capacities. [23] [24] Bitcoin mining may also incentivize the recommissioning of fossil fuel plants. [25] For instance, Greenidge Generation, a closed coal-fired power plant in New York State, was converted into natural gas in 2017 and started mining bitcoin in 2020 to monetize off-peak periods. [20] Such impact is difficult to quantify directly. [25]
Bitcoin has been mined via electricity generated through the combustion of associated petroleum gas (APG), which is a methane-rich byproduct of crude oil drilling that is sometimes flared or released into the atmosphere. [26] Methane is a greenhouse gas with a global warming potential 28 to 36 times greater than CO2. [4] By converting more of the methane to CO2 than flaring alone would, using APG generators reduces the APG's contribution to the greenhouse effect, but this practice still harms the environment. [4] In places where flaring is prohibited this practice has allowed more oil drills to operate by offsetting costs, delaying fossil fuel phase-out. [4] Commenting on one pilot project with ExxonMobil, political scientist Paasha Mahdavi noted in 2022 that this process could potentially allow oil companies to report lower emissions by selling gas leaks, shifting responsibility to buyers and avoiding a real reduction commitment. [27]
In a 2023 study published in Ecological Economics , researchers from the International Monetary Fund estimated that the global payment system represented about 0.2% of global electricity consumption, comparable to the consumption of Portugal or Bangladesh. [28] For bitcoin, energy used is estimated around 500 kilowatt-hours per transaction, compared to 0.001 kWh for credit cards (not including consumption from the merchant's bank, which receives the payment). [28] However, bitcoin's energy expenditure is not directly linked to the number of transactions. Layer 2 solutions, like the Lightning Network, and batching, allow bitcoin to process more payments than the number of on-chain transactions suggests. [28] [29] For instance, in 2022, bitcoin processed 100 million transactions per year, representing 250 million payments. [28]
Bitcoins are usually mined on specialized computing hardware, called application-specific integrated circuits, with no alternative use beyond bitcoin mining. [2] Due to the consistent increase of the bitcoin network's hashrate, one 2021 study estimated that mining devices had an average lifespan of 1.3 years until they became unprofitable and had to be replaced, resulting in significant electronic waste. [2] This study estimated bitcoin's annual e-waste to be over 30,000 tonnes (comparable to the small IT equipment waste produced by the Netherlands) and each transaction to result in 272 g (9.6 oz) of e-waste. [2] A 2024 systematic review criticized this estimate and argued, based on market sales and IPO data, that bitcoin mining hardware lifespan was closer to 4–5 years. [30]
According to a 2023 non-peer-reviewed commentary, bitcoin's water footprint reached 1,600 gigalitres (5.7×1010 cu ft) in 2021, due to direct water consumption on site and indirect consumption from electricity generation. [31] The author notes that this water footprint could be mitigated by using immersion cooling and power sources that do not require freshwater such as wind, solar, and thermoelectric power generation with dry cooling. [31]
China's 2021 bitcoin mining ban was partly motivated by its role in illegal coal mining and environmental concerns. [32] [33]
In September 2022, the US Office of Science and Technology Policy highlighted the need for increased transparency about electricity usage, greenhouse gas emissions, and e-waste. [34] In November 2022, the US Environmental Protection Agency confirmed working on the climate impacts of cryptocurrency mining. [35] In the US, New York State banned new fossil fuel mining plants with a two-year moratorium, citing environmental concerns, [4] while Iowa, Kentucky, Montana, Pennsylvania, Rhode Island, Texas, and Wyoming encourage bitcoin mining with tax breaks. [4] [36] Texas incentives aim to cut methane emissions from flared gas using bitcoin mining. [36] In January 2024, the US Energy Information Administration launched a mandatory survey of cryptocurrency miner energy use but suspended it one month later after it was successfully challenged by miners before the United States District Court for the Western District of Texas. [37]
In Canada, due to high demand from the industry and concerned that their renewable electricity could be better used, the provinces Manitoba and British Columbia paused new connections of bitcoin mining facilities to the hydroelectric grid in late 2022 for 18 months while Hydro-Québec increased prices and capped usage for bitcoin miners. [38]
In October 2022, due to the global energy crisis, the European Commission invited member states to lower the electricity consumption of crypto-asset miners and end tax breaks and other incentives benefiting them. [39]
Electric power systems consist of generation plants of different energy sources, transmission networks, and distribution lines. Each of these components can have environmental impacts at multiple stages of their development and use including in their construction, during the generation of electricity, and in their decommissioning and disposal. These impacts can be split into operational impacts and construction impacts. All forms of electricity generation have some form of environmental impact, but coal-fired power is the dirtiest. This page is organized by energy source and includes impacts such as water usage, emissions, local pollution, and wildlife displacement.
Energy is sustainable if it "meets the needs of the present without compromising the ability of future generations to meet their own needs." Definitions of sustainable energy usually look at its effects on the environment, the economy and society. These impacts range from greenhouse gas emissions and air pollution to energy poverty and toxic waste. Renewable energy sources such as wind, hydro, solar, and geothermal energy can cause environmental damage, but are generally far more sustainable than fossil fuel sources.
Proof of work (PoW) is a form of cryptographic proof in which one party proves to others that a certain amount of a specific computational effort has been expended. Verifiers can subsequently confirm this expenditure with minimal effort on their part. The concept was invented by Moni Naor and Cynthia Dwork in 1993 as a way to deter denial-of-service attacks and other service abuses such as spam on a network by requiring some work from a service requester, usually meaning processing time by a computer. The term "proof of work" was first coined and formalized in a 1999 paper by Markus Jakobsson and Ari Juels. The concept was adapted to digital tokens by Hal Finney in 2004 through the idea of "reusable proof of work" using the 160-bit secure hash algorithm 1 (SHA-1).
Climate change mitigation (or decarbonisation) is action to limit the greenhouse gases in the atmosphere that cause climate change. Climate change mitigation actions include conserving energy and replacing fossil fuels with clean energy sources. Secondary mitigation strategies include changes to land use and removing carbon dioxide (CO2) from the atmosphere. Current climate change mitigation policies are insufficient as they would still result in global warming of about 2.7 °C by 2100, significantly above the 2015 Paris Agreement's goal of limiting global warming to below 2 °C.
A carbon footprint (or greenhouse gas footprint) is a calculated value or index that makes it possible to compare the total amount of greenhouse gases that an activity, product, company or country adds to the atmosphere. Carbon footprints are usually reported in tonnes of emissions (CO2-equivalent) per unit of comparison. Such units can be for example tonnes CO2-eq per year, per kilogram of protein for consumption, per kilometer travelled, per piece of clothing and so forth. A product's carbon footprint includes the emissions for the entire life cycle. These run from the production along the supply chain to its final consumption and disposal.
A low-carbon economy (LCE) is an economy which absorbs as much greenhouse gas as it emits. Greenhouse gas (GHG) emissions due to human activity are the dominant cause of observed climate change since the mid-20th century. There are many proven approaches for moving to a low-carbon economy, such as encouraging renewable energy transition, energy conservation, electrification of transportation, and carbon capture and storage. An example are zero-carbon cities.
Greenhouse gas (GHG) emissions from human activities intensify the greenhouse effect. This contributes to climate change. Carbon dioxide, from burning fossil fuels such as coal, oil, and natural gas, is one of the most important factors in causing climate change. The largest emitters are China followed by the United States. The United States has higher emissions per capita. The main producers fueling the emissions globally are large oil and gas companies. Emissions from human activities have increased atmospheric carbon dioxide by about 50% over pre-industrial levels. The growing levels of emissions have varied, but have been consistent among all greenhouse gases. Emissions in the 2010s averaged 56 billion tons a year, higher than any decade before. Total cumulative emissions from 1870 to 2022 were 703 GtC, of which 484±20 GtC from fossil fuels and industry, and 219±60 GtC from land use change. Land-use change, such as deforestation, caused about 31% of cumulative emissions over 1870–2022, coal 32%, oil 24%, and gas 10%.
A coal-fired power station or coal power plant is a thermal power station which burns coal to generate electricity. Worldwide there are over 2,400 coal-fired power stations, totaling over 2,130 gigawatts capacity. They generate about a third of the world's electricity, but cause many illnesses and the most early deaths, mainly from air pollution. World installed capacity doubled from 2000 to 2023 and increased 2% in 2023.
Fossil fuel phase-out is the gradual reduction of the use and production of fossil fuels to zero, to reduce deaths and illness from air pollution, limit climate change, and strengthen energy independence. It is part of the ongoing renewable energy transition, but is being hindered by fossil fuel subsidies.
China is the largest producer and consumer of coal and coal power in the world. The share of coal in the Chinese energy mix declined to 55% in 2021 according to the US Energy Information Agency.
The environmental impact of the energy industry is significant, as energy and natural resource consumption are closely related. Producing, transporting, or consuming energy all have an environmental impact. Energy has been harnessed by human beings for millennia. Initially it was with the use of fire for light, heat, cooking and for safety, and its use can be traced back at least 1.9 million years. In recent years there has been a trend towards the increased commercialization of various renewable energy sources. Scientific consensus on some of the main human activities that contribute to global warming are considered to be increasing concentrations of greenhouse gases, causing a warming effect, global changes to land surface, such as deforestation, for a warming effect, increasing concentrations of aerosols, mainly for a cooling effect.
Individual action on climate change can include personal choices with regards to diet, travel, lifestyle, consumption of goods and services, family size and so on. Individuals can also get active in local and political advocacy work around climate action. People who wish to reduce their carbon footprint, can for example reduce air travel and driving cars, they can eat mainly a plant-based diet, use consumer products for longer, or have fewer children. Avoiding meat and dairy foods has been called "the single biggest way" how an individual can reduce their environmental impact. Scholars find that excessive consumption is more to blame for climate change than population increase. High consumption lifestyles have a greater environmental impact, with the richest 10% of people emitting about half the total lifestyle emissions.
Variable renewable energy (VRE) or intermittent renewable energy sources (IRES) are renewable energy sources that are not dispatchable due to their fluctuating nature, such as wind power and solar power, as opposed to controllable renewable energy sources, such as dammed hydroelectricity or bioenergy, or relatively constant sources, such as geothermal power.
A cryptocurrency, crypto-currency, or crypto is a digital currency designed to work as a medium of exchange through a computer network that is not reliant on any central authority, such as a government or bank, to uphold or maintain it.
An energy transition is a major structural change to energy supply and consumption in an energy system. Currently, a transition to sustainable energy is underway to limit climate change. As much sustainable energy is renewable it is also known as the renewable energy transition. The current transition aims to reduce greenhouse gas emissions from energy quickly and sustainably, mostly by phasing-down fossil fuels and changing as many processes as possible to operate on low carbon electricity. A previous energy transition perhaps took place during the Industrial Revolution from 1760 onwards, from wood and other biomass to coal, followed by oil and later natural gas.
The Bitcoin protocol is the set of rules that govern the functioning of Bitcoin. Its key components and principles are: a peer-to-peer decentralized network with no central oversight; the blockchain technology, a public ledger that records all Bitcoin transactions; mining and proof of work, the process to create new bitcoins and verify transactions; and cryptographic security.
Coal, cars and lorries vent more than a third of Turkey's six hundred million tonnes of annual greenhouse gas emissions, which are mostly carbon dioxide and part of the cause of climate change in Turkey. The nation's coal-fired power stations emit the most carbon dioxide, and other significant sources are road vehicles running on petrol or diesel. After coal and oil the third most polluting fuel is fossil gas; which is burnt in Turkey's gas-fired power stations, homes and workplaces. Much methane is belched by livestock; cows alone produce half of the greenhouse gas from agriculture in Turkey.
China's greenhouse gas emissions are the largest of any country in the world both in production and consumption terms, and stem mainly from coal burning, including coal power, coal mining, and blast furnaces producing iron and steel. When measuring production-based emissions, China emitted over 14 gigatonnes (Gt) CO2eq of greenhouse gases in 2019, 27% of the world total. When measuring in consumption-based terms, which adds emissions associated with imported goods and extracts those associated with exported goods, China accounts for 13 gigatonnes (Gt) or 25% of global emissions. According to the Carbon Majors Database, Chinese state coal production alone accounts for 14% of historic global emissions.
Fengqi You is a professor and holds the Roxanne E. and Michael J. Zak Chair at Cornell University in the United States. His research focuses on systems engineering and data science. According to Google Scholar, his h-index is 82.
The environmental impacts of artificial intelligence (AI) may vary significantly. Many deep learning methods have significant carbon footprints and water usage. Some scientists have suggested that artificial intelligence may provide solutions to environmental problems.