(CNN) Smoking kills 7 million people a year, and it scars the planet through deforestation, pollution and littering.

Details of the environmental cost of tobacco are revealed in a study released Wednesday by the World Health Organization, adding to the well-known costs to global health, which translate to a yearly loss of $1.4 trillion in health-care expenses and lost productivity.

From crop to pack, tobacco commands an intensive use of resources and forces the release of harmful chemicals in the soil and waterways, as well as significant amounts of greenhouse gases. Its leftovers linger, as tobacco litter is the biggest component of litter worldwide.

"Tobacco not only produces lung cancer in people, but it is a cancer to the lungs of the Earth," said Dr. Armando Peruga, who previously coordinated the WHO Tobacco Free Initiative and now works as a consultant. He reviewed the new report for the WHO.

Commercial tobacco farming is a worldwide industry that involves 124 countries and occupies 4.3 million hectares of agricultural land. About 90% of it takes place in low-income countries, with China, Brazil and India as the largest producers.

Because tobacco is often a monocrop -- grown without being rotated with other crops -- the plants and the soil are weak in natural defenses and require larger amounts of chemicals for growth and protection from pests.

"Tobacco also takes away a lot of nutrients from the soil and requires massive amounts of fertilizer, a process that leads to degradation of the land and desertification, with negative consequences for biodiversity and wildlife," Peruga said.

The use of chemicals directly impacts the health of farmers, 60% to 70% of whom are women. This is especially prominent in low- and middle-income countries, where some compounds that are banned in high-income countries are still used.

300 cigarettes = one tree

Farming also uses a surprisingly large amount of wood, rendering tobacco a driver of deforestation, one of the leading causes of climate change.

About 11.4 million metric tonnes of wood are utilized annually for curing: the drying of the tobacco leaf, which is achieved through various methods, including wood fires. That's the equivalent of one tree for every 300 cigarettes, or 1.5 cartons.

This adds to the impact of plantations on forest land, which the study describes as a significant cause for concern, citing "evidence of substantial, and largely irreversible, losses of trees and other plant species cause by tobacco farming."

Deadly gases

In 2012, 967 million daily smokers consumed approximately 6.25 trillion cigarettes worldwide, the WHO estimates.

"That means about 6,000 metric tonnes of formaldehyde and 47,000 metric tonnes of nicotine are released into the environment," Peruga said.

Tobacco smoke contains about 4,000 chemicals, at least 250 of which are known to be harmful. It also contains climate-warming carbon dioxide, methane and nitrous oxides. "The combination of greenhouse gases from combustion is equivalent to about 1.5 million vehicles driven annually," Peruga said.

Secondhand smoke is particularly deadly: It contains twice as much nicotine and 147 times more ammonia than so-called mainstream smoke, leading to close to 1 million deaths annually, 28% of them children

Some of these pollutants remain in the environment (and our homes) as "third-hand smoke," accumulating in dust and surfaces indoors, and in landfills. Some, like nicotine, even resist treatment, polluting waterways and potentially contaminating water used for consumption, the study notes.

Non-biodegradable litter

Tobacco litter is the most common type of litter by count worldwide.

"We calculate that two-thirds of every cigarette ends up as litter," Peruga said.

The litter is laced with chemicals including arsenic and heavy metals, which can end up in the water supply. Cigarette butts are not biodegradable, and tossing one on the ground is still considered a socially acceptable form of littering in many countries.

The WHO estimates that between 340 million and 680 million kilograms of tobacco waste are thrown away every year, and cigarette butts account for 30% to 40% of all items collected in coastal and urban clean-ups.

"In addition to that, there are 2 million tons of paper, foil, ink and glue used for the packaging," Peruga said.

A way forward?

Even though smoking is declining globally , it is increasing in some regions, such as the eastern Mediterranean and Africa. China is a world leader both in production (44%) and consumption, with 10 times more cigarettes smoked than in any other nation.

Every stage of the production of a cigarette has negative effects on the environment and the people who are involved in manufacturing tobacco products, even before the health of smokers and non-smokers is affected.

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Although governments worldwide already collect $270 billion in tobacco taxes a year, the WHO suggests that increasing tax and prices is an effective way of reducing consumption and help development priorities in each country, adding that by collecting 80 cents more per pack, the global tax revenue could be doubled.

"Tobacco threatens us all," WHO Director-General Margaret Chan said in a note. "It exacerbates poverty, reduces economic productivity, contributes to poor household food choices, and pollutes indoor air."