The biggest polluting industries in the world are coal, oil, natural gas, agriculture, transport, construction, plastics and fashion, with coal at the top: over 15 billion tonnes of CO2 in 2024, more than a quarter of global greenhouse gas emissions. Global fossil CO2 emissions are projected to hit a record 38.1 billion tonnes in 2025, up 1.1%. This list is unranked, because industries overlap, except that we single out two as the worst.
We could start by telling you how many tons of CO2 go into the atmosphere every hour, but numbers like these lose meaning without a frame of reference. So let’s look at the industries that pollute and point out a few practical solutions. There’s no measurable way of comparing one industry with another, partly because one industry relies on another. That’s why this list isn’t in any particular order, apart from the last two.
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The 15 industries at a glance
| # | Industry | Key issue |
|---|---|---|
| 1 | Agriculture | Land use, livestock and fertilizer |
| 2 | Food Retail and Food Waste | Packaging and what gets thrown away |
| 3 | Passenger Transport | Cars, planes and trains |
| 4 | Commercial Freight | Moving the stuff we buy |
| 5 | Tourism | Flights, hotels and souvenirs |
| 6 | Construction | Cement, waste and noise |
| 7 | Natural Gas | The friendlier cousin that isn’t |
| 8 | Fashion | Fast fashion and textile waste |
| 9 | Chemical Manufacturing | Energy-hungry and toxic |
| 10 | The Plastics Industry | 368 million tonnes a year |
| 11 | Waste Management | Landfills and leaks |
| 12 | Mining | Digging up the materials we need |
| 13 | Technology and Data Centers | The AI power bill |
| 14 | Oil | Spills, drilling and carbon |
| 15 | Coal | The worst of the worst |
1. Agriculture
Farming serves one of our most basic needs, so we can’t live without it. But agriculture and the industrial energy sector each accounted for about 11% of global greenhouse gas emissions in the most recent estimate (57.7 Gt CO2-equivalent for 2024). Livestock and the feed grown for it occupy about a third of Earth’s ice-free land and are a contributing factor in species extinction, desertification and habitat destruction. Every link of the beef chain is heavy: fertilizer for feed, forests cleared for grazing land, and methane from cattle. Swapping beef for chicken or beans is one of the biggest personal changes you can make.
2. Food Retail and Food Waste
This one isn’t about growing food. It’s about how companies package, transport and sell it. Wasted food alone amounts to 3.3 billion tons of carbon dioxide equivalent emissions a year, and food in landfills is a major source of methane. Solutions you’ve heard before still work: reusable bags, shops with little or no packaging, and planning meals so less gets thrown away.
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3. Passenger Transport
Transport was about 15% of global greenhouse gas emissions in the latest estimate, second only to the power sector at roughly 27%. Planes get the headlines, but global commercial aviation produced 2.4% of all CO2 emissions in 2018, so land travel pollutes more. International aviation is rising again: the 2025 Global Carbon Budget projects emissions up 6.8%, exceeding pre-COVID levels. Limit your plane journeys, carpool, take public transport, and consider an electric car now that they are so widely available.
4. Commercial Freight
The other side of transport: carrying goods rather than people. Everything we order online, from dinner to products shipped halfway across the world, has to be moved by trucks, ships and planes. Most freight is addressed to companies, not individuals, and it sits inside the transport total above, so it is hard to separate cleanly. Shipping emissions were projected to stay flat in 2025.
5. Tourism
The tourism sector accounts for about 5% of global CO2 emissions according to one commonly used estimate, with aviation making up 40% of CO2 emissions related to tourist transportation. International tourist arrivals reached 1.523 billion in 2025, so the footprint is growing. Add cheap plastic souvenirs, wasted restaurant food, daily towel washing and cruise ship wastewater, and it all adds up to more pollution.
6. Construction
Now to one of the kings of the industries that pollute. Cement production alone is responsible for nearly 8% of global CO2 emissions (2018), through fuel burned in kilns and the CO2 released when limestone is heated. Construction also produces large amounts of landfill waste, dust and noise pollution, the world’s most ignored kind of pollution.
7. Natural Gas
We’ve often thought of natural gas as the friendlier cousin of the other fossil fuels, which is kind of true. But given the company it’s in, that’s not saying much. Natural gas is primarily methane, the second-greatest greenhouse gas after carbon dioxide. The 2025 Global Carbon Budget projects gas emissions up about 1.3% in 2025, the fastest of the three fossil fuels.
8. Fashion
According to the United Nations Environment Programme, consumers are buying approximately 60% more clothing than in the past while keeping garments for about half as long. A 2020 scientific review estimated that the fashion industry produces more than 92 million tonnes of waste and consumes about 79 trillion liters of water a year. Fast fashion is the section we can point our fingers at: cheap, non-biodegradable synthetic fibers, microplastics and low-cost production in countries with weaker environmental rules. At Alux we’ve often said: buy quality that will last, buy second-hand, and recycle instead of binning.
If you want guidance about recycling and styling your clothes according to different seasons, check out 10 Tips On How To Transition Clothes From Summer To Fall.
9. Chemical Manufacturing
Every kind of manufacturing uses energy, and a lot of it dirty energy, but chemicals are reportedly the biggest industrial user of energy by a long way. The cleaning products at home, the pesticides farmers use and the materials builders use all took their toll on the environment before they got used. The industry also releases toxic substances that can contaminate water, soil, air and food, worst in places with fewer regulations.
10. The Plastics Industry
About 368 million tonnes of plastic were produced in 2019. From the 1950s up to 2018, an estimated 6.3 billion tonnes of plastic waste was generated worldwide, of which an estimated 9% was recycled and another 12% incinerated. As of 2020, the global mass of produced plastic exceeds the biomass of all land and marine animals combined. The good news is that plastic decomposes. The bad news is it takes hundreds of years, so the best solution is the same as for most problems: consume less, reuse and recycle.
11. Waste Management
Getting rid of waste is a big business, and it can’t be done perfectly. Waste management usually comprises 20 to 50% of municipal budgets. Landfills release methane, and harmful chemicals can leak into the land and groundwater around them. The waste hierarchy of reduce, reuse and recycle is still the most effective approach.
12. Mining
Metals and minerals from the ground may be useful, but extracting them does no favors to the natural surroundings. Mining can cause erosion, sinkholes, loss of biodiversity and the contamination of soil, groundwater and surface water by chemicals. Land is cleared extensively, and operations consume large amounts of energy and water and produce hazardous waste.
13. Technology and Data Centers
This one is very two-edged. The tech industry gave us solar and plenty of solutions. But data centers consumed around 415 terawatt hours of electricity in 2024, about 1.5% of global electricity, growing 12% a year over the previous five years, as the AI boom drives new data centers. Opposition has been blocking or delaying projects too: a first report found $64 billion in data center projects blocked or delayed between May 2024 and March 2025. Phones and computers also rely on mined minerals.
There are two industries that we think are by far the worst polluters, and we’ve saved them for last. The second worst is…
14. Oil
No surprises here. Oil is one of the giant industries that pollute the world, from the areas where it drills to oil spills in the world’s seas and oceans. But the biggest reason it is so close to the top is the carbon dioxide it sends into the atmosphere. The 2025 Global Carbon Budget projects oil emissions up about 1% in 2025 as part of record fossil CO2 emissions of 38.1 billion tonnes. But as bad a rap as oil gets, it still isn’t the world’s number one polluter. That dubious honor goes to…
15. Coal
Finally, we’ve come to the worst of the worst. Over fifteen billion tonnes of CO2 were emitted by burning coal in 2024, more than a quarter of total global greenhouse gas emissions, and a record amount of coal was burnt that year. The International Energy Agency estimated global coal demand at 5,946 megatonnes in 2024 and 5,964 in 2025. Consumption is expected to peak before 2030, but that is not yet in the data. Coal also causes smog, which leads to respiratory problems and heart disease, which is why we put it at the top of this list.
Question: Aluxers, we’ve mentioned a few things we can do to reduce pollution. What other ideas do you have to do your bit to stop polluting?
FAQ
What is the biggest polluting industry in the world?
Coal. Burning it emitted over 15 billion tonnes of CO2 in 2024, more than a quarter of global greenhouse gas emissions.
Which sector emits the most greenhouse gases?
The power sector, at roughly 27% of the 57.7 Gt CO2-equivalent estimated for 2024, followed by transport at about 15%. Industrial energy and agriculture each contribute about 11%.
Are global CO2 emissions still rising?
Yes. The 2025 Global Carbon Budget projects record fossil CO2 emissions of 38.1 billion tonnes, up 1.1%, with coal, oil and gas all increasing.
How much electricity do data centers use?
Around 415 terawatt hours in 2024, about 1.5% of global electricity, growing 12% a year over the previous five years.
Is fast fashion a major polluter?
Yes. It leads to more clothes bought and thrown away sooner. Consumers buy about 60% more clothing than in the past and keep garments for about half as long.
How much plastic is recycled?
Of the 6.3 billion tonnes of plastic waste generated from the 1950s to 2018, only an estimated 9% was recycled.
How we put this list together
We chose industries by their share of emissions or waste and avoided ranking them against each other, since they overlap. Figures are the latest global estimates, with their years stated.
Last updated: October 2026.
