If people around the world were as enthusiastic cyclers as they are in the Netherlands, we could cut an impressive amount of planet-heating pollution. The Dutch use bicycles to get around more than folks in any other country, cycling about 2.6 kilometers (1.62 miles) a day.

If that was the trend across the world, it would slash 686 million metric tons of carbon dioxide pollution a year, according to the authors of a new study published this week in the journal Communications Earth & Environment. That’s enormous — roughly equivalent to erasing one-fifth of CO2 emissions from passenger cars globally in 2015.

Cleaning up pollution from transportation is a huge piece of the puzzle when it comes to slowing down the climate crisis that’s causing more brutal heatwaves, droughts, fires, and storms. Transportation currently makes up a quarter of fuel-related greenhouse gas emissions globally, with half of that coming from passenger cars.

Replacing those gas-guzzlers with electric vehicles gets a lot of media attention as a sure-fire way to keep the climate crisis at a more manageable level. But that transition is happening slowly, and it doesn’t go far enough in reimagining a more sustainable future for transportation.

The bigger picture, beyond cars, includes communities designed to make it easier for people to get around by public transportation, on foot, and on bicycle. Bicycles, in particular, are great for replacing car trips that might be too far to walk and too short for transit, the authors of the new study point out.

They found that bicycle production has actually grown faster than car production between 1962 and 2015. But owning a bike doesn’t cleanly translate to actually using that bike regularly, their study shows. That’s the case in the US, where bicycles tend to be used more for leisure than commuting. Bicycles were used for less than five percent of daily trips in most of the countries studied.

Wu Chen, SDU Life Cycle Engineering, Department of Green Technology, University of Southern Denmark

The difference in the Netherlands and similar countries like Denmark, where there were high rates of owning and using a bike to get around, the paper says, often boils down to culture and environment. Bicycling might be seen as more dangerous, the paper notes, in some places with high traffic death rates where cyclers might have to navigate through streets crammed with cars.

To get over those kinds of humps, the new paper calls for “worldwide pro-bicycle policy and infrastructure.” That might look like more protected bicycle lanes or strategies to overcome the world’s driving addiction through carbon taxes or congestion pricing.

This study is the first to put together a worldwide dataset on bicycle ownership and use by country between 1962 and 2015, according to its authors. They pulled together information from the United Nations, travel surveys, journal articles, and industry reports. They ultimately included 60 countries representing 95 percent of the world’s GDP and bicycle production, import, and export.

Congress has officially passed the Inflation Reduction Act after a successful House vote on Friday, clearing the way for the biggest clean energy package in US history. President Joe Biden is expected to sign the bill into law soon, bringing the US within eyeshot of reaching its climate goals under the Paris accord.

The bulk of the bill’s spending — $369 billion — goes toward building up domestic manufacturing of electric vehicles and clean energy technologies plus making homes and buildings more energy-efficient. There’s another $4 billion to promote drought resiliency in the western US. Outside of climate initiatives, the bill also spends $64 billion on healthcare subsidies to prevent insurance premiums from rising for people who buy their coverage through the public marketplace.

The Inflation Reduction Act manages to cut US greenhouse gas emissions by roughly 40 percent from peak levels this decade, according to independent analyses. That’s still short of the 50 to 52 percent cut Biden committed to under the Paris climate accord. But it would go a long way toward preventing disastrous heatwaves, wildfires, hurricanes, and other climate-driven calamities from growing even worse as global temperatures rise. Globally, greenhouse gas emissions need to fall roughly by half this decade to avoid things like coral reef extinction and more than doubling the percentage of the global population exposed to extreme heatwaves.

The bill was seen as Democrats’ last chance to pass sweeping climate legislation while still holding a narrow majority in Congress. The Senate passed the reconciliation bill after dramatic and fraught negotiations with Sen. Joe Manchin (D-WV) over more than a year.

As part of the compromise, the final bill will water down pollution-cutting provisions compared to earlier versions and mandate more federal lease sales for oil and gas drilling. It also expands tax credits for controversial carbon capture technologies backed by fossil fuel companies. Big Oil uses the technology for “enhanced oil recovery” — shooting captured carbon into the ground to extract hard-to-reach reserves — and then claims that the oil they produce is “carbon neutral.”

In another concession to Manchin, Democrats are also working on a side deal that would streamline natural gas pipeline permitting. Those measures could prolong fossil fuel dependence and the pollution that comes with it — continuing to harm communities near oil and gas infrastructure, climate and environmental justice advocates warn.

The US remains the second-biggest climate polluter in the world after China and has released the most greenhouse gas emissions historically. So the current push to cut US emissions is crucial to global efforts to limit climate change.

The US is tantalizingly close to passing landmark legislation that would push the country closer than ever toward national and global climate goals. Yesterday, the Senate narrowly passed a budget reconciliation bill after months of stalled negotiations that watered down some climate provisions and then nearly fell through completely. After that roller-coaster ride, we’re left with the Inflation Reduction Act, which invests $369 billion in clean energy and climate action.

If the House passes the bill and Biden signs it into law — which they’re expected to do — it’ll be the most the US has ever spent in one go to tackle the climate crisis that’s driving devastating heatwaves, megafires, and hurricane seasons. While this latest iteration of the climate and energy bill is far from perfect, it would go a long way toward healing the damage humans have inflicted on ourselves.

The world is on a tight deadline to wean itself off of fossil fuels. Burning fossil fuels for energy has the nasty side effect of producing greenhouse gases that heat the planet. Globally, greenhouse gas emissions need to reach net zero by around 2050, an overwhelming body of research has found, to prevent significantly worse disasters that come with global warming above 1.5 degrees Celsius.

Crucially, the bill would slash cumulative greenhouse gas emissions by 6.3 billion metric tons over the next decade, according to a recent analysis by Princeton University’s ZERO Lab. To put that into perspective, it’s more than what the US pumped into the atmosphere in 2020 when it produced roughly 5.2 billion metric tons of emissions.

Right now, there’s a big gap between how much climate pollution the US produces and how much it’s promised to cut back by 2030 under the international Paris agreement. The new bill helps fill in that gap, getting us about two-thirds of the way to our goals, according to the Princeton analysis.

To do that, the bill prioritizes revamping the power sector to run on carbon pollution-free electricity like solar and wind. It will also build up the nation’s manufacturing supply chains for clean energy, make homes and buildings more energy-efficient, and boost electric vehicle adoption.

Some of the big-ticket items are $30 billion in tax credits to make more solar panels, wind turbines, batteries, and process critical minerals needed for manufacturing. There’s another $20 billion in loans for new “clean vehicle manufacturing facilities” and another $9 billion for consumer home energy rebate programs.

That’s all reason for optimism, but there are some wild cards in the bill that could serve as climate roadblocks. It locks in more lease sales for oil and gas drilling, a concession to Senator Joe Manchin (D-WV) — who has made millions from coal and withheld his vote until the bill left some avenues open for fossil fuels to keep a foothold in the US economy. The bill also includes tax credits for carbon capture technologies that can be added to fossil fuel power plants and other polluting facilities to reduce their carbon dioxide emissions. Many environmental advocates are skeptical of carbon capture tech, which oil and gas companies have been pushing as a way to keep demand high for dirtier fuels.

So, even if this bill goes through, there’s still more work for the US to do to clean up its planet-heating pollution. And the stakes for taking action are high. One in five Americans is under an extreme heat warning today. Heat is already the biggest killer in the US when it comes to weather disasters, and it’s one of the threats that rises with global temperatures the longer lawmakers take to act.

Bitcoin miners in the Lone Star State are powering down this week as a punishing heatwave stresses the power grid. Texas’ grid operator asked residents and businesses to conserve energy on Monday with “extreme hot weather driving record power demand across Texas.”

Bitcoin mining companies in the state responded by turning off their machines that otherwise would have used over 1,000 megawatts of electricity, according to the Texas Blockchain Council. That freed up about 1 percent of the grid’s total capacity.

“They are shutting down for several reasons but primarily because it is the right thing to do to be a good ‘grid citizen,’” Lee Bratcher, president of the Texas Blockchain Council, said to The Verge in an email. There are also financial motives, Bratcher said, since spot prices for electricity in Texas skyrocket when power is in short supply.

Bitcoin miners have flocked to Texas over the past year after China banned the practice, and the US subsequently became the biggest hub for mining globally. Those crypto miners are expected to inflate electricity demand in Texas by up to 6 gigawatts by the middle of next year, according to Bloomberg.

Crypto mining companies essentially set up their own data centers filled with specialized hardware that “mine” Bitcoin by racing to solve ever more complex puzzles. That energy-intensive process is done to validate new transactions on the blockchain and allows miners to earn new tokens.

The Bitcoin network, as a result, uses more electricity annually than the country of Belgium. Its energy use, however, is estimated to have dropped over the past month after the price of Bitcoin took a nosedive. A lower value for the cryptocurrency, combined with high energy prices, makes it less profitable to run mining machines. In Texas, one “large publicly traded miner” plans to shut off between 8AM and 10PM for “several days this week,” Bratcher said.

Powering down, especially during those peak hours, also helps Texas’ power grid avoid potential outages. Hot temperatures typically place more pressure on electricity grids as people blast their air conditioners, and Texas is seeing triple-digit heat this week. The heat dome suffocating Texas has also starved it of much of its wind power, which typically generates about a quarter of its electricity. Texas’ power grid is also particularly vulnerable because it doesn’t connect to power grids in other regions. Other states can usually share energy with each other in an emergency.

The state has so far avoided large power outages after the Electric Reliability Council of Texas, or ERCOT, asked Texans to voluntarily reduce their power consumption on Monday. Back in February 2021, a deadly cold snap caused massive outages across the state. Stifling temperatures are forecast to continue throughout the week in Texas, so its power grid isn’t out of the woods yet.

This isn’t the first time that Bitcoin miners in the state have responded to a power crunch during high temperatures, and it probably won’t be the last. Riot Blockchain, a Bitcoin mining company, curtailed 8,648 megawatt-hours of energy consumption throughout June, Riot marketing coordinator Alexis Brock said in an email to The Verge. That’s significant because Riot operates a facility in Rockdale, Texas which it claims is North America’s biggest Bitcoin mining facility. The company plans for the facility to continue to ramp down as needed this summer when peak power demand threatens the stability of the grid.

In an executive action on Monday, President Joe Biden announced a number of measures aimed at boosting solar energy in the US, including a two-year “bridge” meant to alleviate a squeeze on the flow of solar equipment imports from Cambodia, Malaysia, Thailand, and Vietnam.

The moves come after a federal investigation into whether solar manufacturers had been evading tariffs on goods from China by exporting them through other countries. The Department of Commerce says it will levy penalties on companies that it finds are evading taxes as part of its investigation, but only after the two-year reprieve from tariffs on imports from Southeast Asia ends.

Alongside the tariff holiday, the executive order includes two measures meant to boost domestic production of solar panels and other clean energy technology. Under the terms of the order, the White House will invoke the Defense Production Act to prioritize solar equipment, reportedly through a series of grants and loans. Biden established new measures to make it easier for federal agencies to procure items made in the US.

That’s supposed to prevent shortages of solar panels while the US works to ramp up domestic production. In 2020, only 3 percent of all the solar panels shipped around the world were made in the US. The majority of the world’s solar panels, and the materials used to make them, come from China.

While solar power is the focus, the impact of the order will extend far beyond just solar panels. Heat pumps and building insulation are included in the DPA action, as are transformers and other critical components needed to update the nation’s power grid. The list also includes electrolyzers and related materials used to make hydrogen fuel that the Biden administration hopes will help clean up heavy-duty trucks and steel manufacturing.

In March, the Department of Commerce launched an investigation into whether solar panel manufacturers have evaded tariffs by funneling Chinese goods through Southeast Asia. That investigation, which might have placed retroactive tariffs of up to 250 percent on the contested goods, threatened to cut solar installations in the US nearly in half through 2023, according to an April forecast by the Solar Energy Industries Association.

Now, it seems that retroactive tariffs are “off the table,” Reuters reports, based on information from sources close to the matter. But the investigation is still underway and could result in penalties after the two-year tariff break.

President Biden’s strategy to clean up US greenhouse gas emissions includes building up US supply chains for clean energy. In March, he invoked the Defense Production Act to speed up mining and the processing of key minerals used in batteries for renewable energy and electric vehicles. The Act gives the president the power to push companies to prioritize federal contracts for whatever goods or materials it deems necessary in a national emergency.

“As droughts cripple the West and Russia’s unwarranted invasion of Ukraine have placed increasing strains on America’s energy market, preventing disruptions to the electric power system, diversifying our energy sources and responding to the climate crisis have never been more urgent, and solar energy is an essential component of meeting those needs,” Secretary of Commerce Gina Raimondo said in a statement today.

The Biden administration says the US is now set to triple its solar manufacturing capacity by 2024. That’ll be crucial given how far behind the US is on meeting its climate goals. After he recommitted the US to the Paris Agreement, Biden pledged that the nation would slash its carbon dioxide emissions by at least half this decade compared to peak emissions in 2005.

But the US is only on track to reduce energy-related emissions by up to 28 percent by 2030, according to an analysis published last month in the journal Science. Solar and wind capacity in the US needs to grow at a rate two to seven times faster than they have over the past decade for the US to hit its emissions reduction target, according to the analysis.

The Department of Energy (DOE) just launched a new $3.5 billion program to take carbon dioxide out of the atmosphere and store it away. The program focuses on developing four “hubs” across the country focused on direct air capture, the technology that draws CO2 out of the air.

Each of the hubs is ultimately supposed to be able to capture and store at least a million metric tons of CO2. That’s a massive endeavor. Currently, all the direct air capture facilities in the world only have the capacity to capture about 0.01 million metric tons of CO2.

Today, the DOE filed a Notice of Intent — a kind of official “heads-up” — that says that they’ll be making a funding announcement related to those hubs “in the fourth quarter of Fiscal Year 2022.” At that point, companies can apply for funds to develop projects that will “contribute to the development” of those hubs. The funding comes from the Bipartisan Infrastructure Law passed last year and is supposed to be deployed between 2022 and 2026. The Biden administration is billing this effort as part of its plan to reduce the United States’ greenhouse gas emissions by at least 50 percent this decade compared to 2005 pollution levels.

For projects to be eligible for the funding, they have to meet certain criteria. They need to be able to permanently store the CO2, rather than using it in products like fizzy drinks. That ensures that the greenhouse gas doesn’t quickly wind up in the atmosphere again. The DOE is also barring any projects that would use the captured CO2 to produce more fossil fuels. That excludes the oil and gas industry’s “enhanced oil recovery,” a technique that involves shooting captured carbon dioxide into the ground to force out hard-to-reach oil reserves.

The exact locations of the hubs haven’t been decided yet, but the government hopes that by lumping different projects together into hubs, they can cut costs and scale up quickly. Ideally, different facilities would be able to share the same infrastructure — i.e., pipelines to transport the captured CO2 to somewhere it can be stored nearby.

The plan is for at least two of the hubs to be located in “economically distressed communities in the regions of the United States with high levels of coal, oil, or natural gas resources.” Some advocates from communities already surrounded by a lot of polluting facilities, however, are wary about carbon removal projects burdening them with even more industrial infrastructure. The DOE said in its announcement that it would consult communities that might be affected.

The DOE will also be looking for regions with other kinds of heavily polluting industry. While this round of funding excludes similar technologies that scrub CO2 out of smokestack emissions instead of the ambient air, siting these different technologies near each other might also allow them all to share the same pipelines to cut down costs. And since the oil and gas industry has experience with building pipelines, including those for CO2, having that expertise nearby could come in handy during the build-out of these hubs.

Taking all that into consideration, it looks like the Gulf Coast could be a prime candidate for such hubs since it has a long history with oil, gas, and petrochemicals. On top of that, there’s already speculation that oil and gas companies are eyeing the bottom of the Gulf of Mexico as a place to deposit captured CO2. We’ll likely learn more about the project in the funding announcement later this year.

The Department of Energy (DOE) opened up billions of dollars in funding today to build up domestic supply chains for batteries. Batteries will be crucial in the Biden administration’s plans to transition the nation to electric vehicles and clean energy.

The DOE says in its announcement that it will give $3.1 billion to companies to boost “the creation of new, retrofitted, and expanded commercial facilities” to process materials, make batteries, and recycle them at the end of their lives. Another $60 million in grants from the DOE will fund efforts to find second uses for old EV batteries. The money comes from the Bipartisan Infrastructure Law that passed last year.

The bigger picture: the Biden administration has set pretty big goals for clean energy and transportation in the US. He committed the US, under the Paris climate agreement, to halving its greenhouse gas emissions this decade. To do that, the administration wants to get the power grid to run completely on carbon pollution-free energy by 2035 and make sure that half of all new car sales are electric or hybrid vehicles by the end of the decade.

That kind of future hinges on having the battery technology to make electric vehicles more affordable as well as to store wind and solar energy so that it’s available when sunshine and winds wane.

Without taking action, a DOE analysis last year found that US battery production capacity wouldn’t be able to meet even half of the projected demand for lithium-ion batteries for electric vehicles in 2028. Right now, battery supply chains are especially vulnerable because they’re concentrated in just a handful of countries. That’s led to allegations of labor abuses, like a lawsuit against Tesla and other companies for the deaths of child workers.

Today’s announcement is just the latest among a series of moves the Biden administration has made to get its hands on more (and better) batteries. In March, Biden invoked the Defense Production Act to bolster domestic mining and the processing of minerals like nickel, lithium, cobalt, graphite, and manganese that are vital for battery-making. Last June, the Department of Energy put out a “national blueprint” for making lithium batteries. All in all, the Bipartisan Infrastructure Law includes $7 billion for domestic battery supply chains — from gathering raw materials to making battery cells and recycling them at the end of their lives.

With gas prices painfully high, there’s a new plea coming from the international agency established to secure the globe’s oil supply: drive less to avoid a deeper energy crunch. That was the key takeaway from a 10-point plan the International Energy Agency (IEA) released today as the world nears peak oil demand season.

“As a result of Russia’s appalling aggression against Ukraine, the world may well be facing its biggest oil supply shock in decades, with huge implications for our economies and societies,” IEA Executive Director Fatih Birol said in a press release. “We can also take action on demand to avoid the risk of a crippling oil crunch.”

If advanced economies — which account for nearly half of global oil demand — can cut back on their oil habit, they could slash demand by 2.7 million barrels a day within four months, the agency says. That would be like erasing the demand for oil from all the cars in China, according to the IEA.

Some of the fixes that cut down on gas demand the most, per the IEA, are surprisingly simple. For starters, carpool. Of course, you could take public transport, walk, or bike instead. The IEA asks public transit operators to reduce their fares to encourage more people to take buses and trains.

The IEA also proposes working from home several times a week to avoid the commute. Perhaps the biggest lift it proposes is for cities to designate “Car-free Sundays.” At the bottom of the list is a suggestion to “Reinforce the adoption” of electric and more efficient vehicles — electric cars can’t save consumers from soaring costs anyway.

If you do need to take your old gas-guzzler somewhere, the IEA suggests you take other measures to improve fuel efficiency — like turning the air conditioning to a lower setting and monitoring your car’s tire pressure. Don’t drive as fast; the IEA recommends lowering speed limits. And of course, cars aren’t the only vehicles to use oil — when it comes to flying, the IEA recommends taking a train or other modes of transportation instead.

While these measures were spurred by the immediate crisis of war, it’s worth getting used to these changes in the long run. After all, oil dependency is making other crises worse. “Reducing oil use must not remain a temporary measure,” the IEA said today. “Sustained reductions are important not only to improve countries’ energy security but also to tackle climate change and reduce air pollution.”

The European Union announced new plans today to swiftly shrink its reliance on Russian gas and accelerate its transition to clean energy. Russia’s brutal invasion of Ukraine and continued threats to further squeeze Europe’s gas and oil supplies have made clean energy an even more critical priority.

“It is time we tackle our vulnerabilities and rapidly become more independent in our energy choices. Let’s dash into renewable energy at lightning speed,” European Commission Executive Vice President Frans Timmermans said in a March 8th statement.

Over the next year, the European Commission says it can drastically cut its gas use by changing how it heats homes and powers buildings. Russian gas accounted for nearly half of the bloc’s gas supply last year. That’ll shrink down to zero “well before” the end of the decade, if the European Commission follows through on goals set out today.

Eventually phasing out gas will trigger makeovers in homes, buildings, and the power sector. Those changes were already on the way, thanks to Europe’s plans to tackle climate change. Things just have to happen much faster now.

“A lot of the blockers for further reduction in fossil fuel dependence will be much easier to remove,” Charles Moore, European programme lead at energy think tank Ember, told The Verge in an interview in advance of the European Commission’s new announcements. “There’s nothing like a really terrifying crisis to unwind that inertia.”

A painful gas shortage had already driven heating and energy prices up across the continent over the past year. Much of that was triggered by a steep rise in gas demand as economies emerged from pandemic-induced shutdowns, although other factors have contributed to the crisis. Russian President Vladimir Putin’s hostility has made things even more volatile. Just today, Russian officials threatened to shut down a major pipeline that brings gas from Russia to Germany in response to heightened sanctions from the West.

“We must become independent from Russian oil, coal and gas. We simply cannot rely on a supplier who explicitly threatens us,” European Commission President Ursula von der Leyen said in a statement today.

The European Commission’s new plan includes speeding up permitting for renewable energy projects. It also wants to ramp up deployment of rooftop solar panels this year. To power heavy industry, it wants to replace Russian gas with hydrogen fuel made with renewable energy. It envisions a “Hydrogen Accelerator” to encourage more storage, port, and transport infrastructure for the fuel. The European Commission also wants to double the bloc’s production of biomethane made from waste by 2030.

Another key pillar of the EU’s plan is boosting energy efficiency. Renovating homes and buildings so that they use less energy is one of the easiest things Europe can do to reduce its gas consumption. And while winter is winding down, Europe needs to start getting ready for the next one — ostensibly without relying on as much Russian gas for heating. Replacing gas heating with more efficient electric heat pumps is another top priority between now and next winter, experts tell The Verge. The European Commission now plans to get 10 million heat pumps out to residents over the next five years.

While the European Union made plans to wean itself off its dependency on fossil fuels from Russia in the long-term, the US today imposed an immediate ban on Russian energy imports. As the world’s leading oil and gas producer, the US is far less reliant on Russian fuel.

“We can take this step when others cannot,” US President Joe Biden said at a press conference today. “But we’re working closely with Europe and our partners to develop a long term strategy to reduce their dependence on Russian energy as well.”

The US has already boosted its exports of liquified natural gas to Europe in recent months. And the EU today said that, for now, it will rely more on imports from the US and places outside of Russia to replenish dwindling gas stores. The commission wants gas storage filled to 90 percent of capacity by October in preparation for winter heating demand.

But there are concerns that turning to new places for gas could prolong Europe’s reliance on the fossil fuel. Germany, for example, recently decided to build new terminals to import liquified natural gas.

When it comes to the power sector, gas-fired power plants currently fill in gaps in Europe’s growing wind and solar energy capacity. Renewables are increasingly cheap and abundant, but customers need a source of power when winds calm and sunshine fades. Historically, fossil fuels and nuclear power plants have made up for that intermittency while utility-scale batteries and other crucial forms of energy storage are still under development. But with Russian gas off the table, Europe faces two controversial options as it builds out more renewable energy: nuclear and coal.

The debate over what role nuclear energy will play in the world’s clean energy transition was already heating up before Russia invaded Ukraine. It’s even more complicated now. Last week, the International Energy Agency proposed maximizing power generation from nuclear power plants as part of a 10-point plan for slashing Europe’s gas imports from Russia. Belgian and German officials have similarly mulled over extending their countries’ nuclear programs over the past week.

But Germany did an about-face again today, with officials shooting down the possibility of keeping the country’s few remaining power plants open beyond their previously planned shutdowns this year. Germany had planned to retire them over concerns about safety and radioactive waste. Russia’s apparent attack on Ukraine’s largest nuclear power plant last week raised fears of radioactive materials being released.

In the absence of nuclear power and gas, more polluting coal-fired plants could find a lifeline. Power generation from coal in the EU has dropped in half since 2015. Cheap renewables and gas drove that trend, but soaring gas prices now make coal more attractive again.

“There’s definitely a risk of higher emissions in the short-term,” Moore says. But he still sees Europe’s future in clean energy.

Whatever happens next, Europe is about to undergo big changes. “In the course of weeks and days, European history has been changed,” Timmermans said in a statement yesterday on the war in Ukraine’s impact on energy and environmental policy. “Europe will never be the way it was before.”

Democratic lawmakers are pushing Bitcoin mining companies in the US to divulge how much electricity they use in an effort to assess how that will impact nearby residents and the environment. Eight members of Congress sent letters yesterday to six companies that mine Bitcoin in the US asking them about the energy and environmental impact of their operations.

“Given the extraordinarily high energy usage and carbon emissions associated with Bitcoin mining, mining operations raise concerns about their impacts on the global environment, local ecosystems, and consumer electricity costs,” the letters say. The letters were signed by Senators Elizabeth Warren (D-MA), Sheldon Whitehouse (D-RI), Jeff Merkley (D-OR), Margaret Hassan (D-NH), and Ed Markey (D-MA). Representatives Katie Porter (D-CA), Rashida Tlaib (D-MI), and Jared Huffman (D-CA) also signed.

The congresspeople asked the companies to answer questions about how much electricity they use, where it comes from, and how they plan to grow in the US. This comes on the heels of an oversight hearing on cryptocurrency mining’s impact on energy held by the House Energy & Commerce Committee last week. During the hearing, experts and lawmakers debated whether cryptocurrencies might play a role in promoting renewable energy or totally derail US climate goals.

Mining certain cryptocurrencies, most notably Bitcoin, gobbles up huge amounts of energy. If Bitcoin were a country, it would rank 27th in the world for its electricity consumption — using more electricity than the country of Ukraine in a single year. If that electricity is generated from fossil fuels, it comes with a lot of pollution that adds to the climate crisis.

The reason Bitcoin uses so much electricity is that it relies on an energy-intensive process called “proof of work” to keep its ledger secure. It requires miners to use specialized computing equipment to solve ever-more-complex puzzles in order to verify transactions. The miners are rewarded with new coins in return.

The proof of work system, which is intentionally energy inefficient in order to dissuade people from tampering with the ledger, is what worries some policymakers and many environmental experts. Different processes use just a fraction of the energy required for proof of work.

In the US, miners’ hunger for energy has already revived aging natural gas and coal plants. For instance, one of the companies that received a letter yesterday, Stronghold Digital Mining, bought two Pennsylvania power plants that now burn coal waste primarily to mine Bitcoin. The company says on its website that, by burning coal waste, it’s helping to clean up “areas that have been ravaged by its presence.” But once burned, the waste pollutes the air and heats up the planet. The EPA has recently cracked down on power plants that dispose of coal waste on site, including two that have been used to power cryptocurrency mining, E&E News reported last week.

Coal waste aside, industry advocates argue that Bitcoin and other cryptocurrencies that use proof of work can clean up their act with renewable energy. And since battery technology currently isn’t advanced enough to store renewable energy whenever there’s more solar and wind power than the grid can handle, they argue that mining operations can make use of the excess energy so that it doesn’t go to waste.

That argument, however, is still largely theoretical. The answers to the questions in the letter lawmakers sent might reveal whether the companies are actually running on clean or dirty energy. There’s some skepticism that miners would be willing to modify the hours during which they run their equipment in order to best make use of renewable energy. The machines typically run 24/7 to maximize profits — not just during daytime when solar power is available.

If mining companies aren’t using excess renewable electricity but instead competing with other customers to fuel their operations, that could drive up utility bills for households and other businesses. That’s already been the case in Plattsburgh, New York, Congress members point out as one example in their letter. Residential utility bills ballooned by up to $300 in 2018 after Bitcoin miners set up shop nearby.

Stronghold and the other companies were asked to respond to the lawmakers’ letter by February 10th. Riot Blockchain Inc., Bitdeer, Bitfury Group, Bit Digital, and Marathon Digital Holdings Inc. also received letters.

“We look forward to having a productive dialogue about the many benefits that we and the rest of our industry have for the United States,” Charlie Schumacher, director of corporate communications for Marathon Digital Holdings, said in an email to The Verge.

“We are proud to do business in America, and we look forward to thoroughly reviewing and earnestly responding to the requested information in the letter we received from the Senate,” Riot Blockchain communications director Trystine Payfer said in an email. A spokesperson for Stronghold Digital Mining also said in an email that they are “excited to engage with Senator Warren and her colleagues.”

The other companies did not immediately respond to a request for comment.

The global center for cryptocurrency mining has shifted from China to the US over the past couple years as China cracked down with policies banning the practice. Now, more than a third of all mining happens in the US, and that’s expected to grow.

Correction 4:43PM Jan. 28: A previous version of this article incorrectly said that Stronghold Digital Mining bought two Pennsylvania power plants that burn coal waste exclusively to mine Bitcoin. This story has been corrected to say that the plants primarily power bitcoin mining; they also provide power to the grid during times of high demand. The story has also been updated to include a statement from Stronghold.

Correction 11:10AM Jan. 31: A previous version of this article incorrectly said that the EPA has recently cracked down on power plants seeking to burn coal waste. The power plants were seeking permission to continue keeping coal waste on site.