Cattle grazing is possibly the most devastating "invasive species" sweeping across the globe, causing ecological degradation and loss of biodiversity. (Photo : Pixabay)

When we think of invasive species, we picture red lionfish hailing from Southeast Asian waters, the emerald ash beetle currently destroying trees in the Midwest, or biting fire ants. But the "invasive species" that is possibly most devastating to ecosystems throughout the world is a little closer to home: cattle grazing.

Livestock are one of the main drivers of ecological degradation globally, and the crisis is only becoming worse. Grazing has a place in just about every agricultural system, but introducing large numbers of grass-munching cattle into areas where cows were not previously found is rapidly wreaking havoc on native ecosystems - so much so that the practice can now be characterized as an "invasive species."

"It's an issue for big businesses, which understand that unsustainable production is a big threat to the industry. It's an issue for the many small producers who are trying to make a living on marginal land and need help to get ecosystems functioning again. And because beef production uses such a large area of land in almost every ecosystem, it's a vital issue for all of us," Ruaraidh Petre, of the sustainable development organization Solidaridad in South Africa, said in a statement.

After habitat loss, invasive species are considered the second largest threat to biodiversity in North America. In the United States, 41 percent of all land is currently grazed by livestock, and at our current meat-consumption rates, that number is likely to go anywhere except up, according to One Green Planet.

Those who directly benefit from cattle grazing and seek to protect this "invasive species" are aiding the extinction of other species like wolves, massive deforestation, biodiversity loss and the erosion of soil and land.

Are Wolves Going to the Wayside?

Wolves are sometimes seen as an invasive species, but they are not the ones you should be worried about. According to the Center for Biological Diversity (CBD), some species of wolves - as well as other animals - have been driven to extinction by the livestock industry, while 175 other species are threatened or endangered. The Mexican gray wolf, for one, is drawing particular concern due to its dwindling numbers.

Hunting and trapping led the Mexican gray wolf (Canis lupus baileyi) to being classified as one of the most endangered mammals in North America.

Wolves were seen as a threat to livestock because they competed for local resources - made scarcer by overgrazing - and saw cows as their prey. Some of these wolves have "already gone extinct in southwestern ecosystems due to 'predator control systems' crafted to protect livestock," wrote One Green Planet.

It wasn't until the Endangered Species Act of 1973 that conservationists started to help this population rebound. Currently, there are only 83 of Mexican gray wolves in the wild. But there is hope that this endangered species is on its way to recovery, as Nature World News recently reported that the first known litter of Mexican gray wolves was born in the wild, according to Mexico City officials.

While that's good news, grazing remains an issue even today, as the Bureau of Land Management (BLM) has granted grazing rights to livestock owners on about 270 million acres of land in North America.

Drivers of Deforestation

Outside of the United States, grazing cattle are a major driver of rainforest deforestation, especially in the famous Amazon. These seemingly harmless cows, the World Wildlife Fund (WWF) reports, are responsible for 80 percent of deforestation in the Amazon, as well as in Latin America's other rain forests.

"Alone, the deforestation caused by cattle ranching is responsible for the release of 340 million tons of carbon to the atmosphere every year, equivalent to 3.4 percent of current global emissions," wrote the WWF.

Beyond that, cattle pastures increase the risk of fires, soil erosion, river siltation and contamination with organic matter. And cattle grazing shows no signs of stopping - Brazil has 88 percent of the Amazon herd, followed by Peru and Bolivia.

While you may not think that you don't play any part in this matter, think again. One Green Planet writes that one football field of tropical rainforest is destroyed every six seconds to produce the equivalent of 257 hamburgers.

This massive tree clearing for the sake of cattle doesn't just displace the thousands of diverse species that call these forests home; it also contributes to global warming by removing potential carbon-storing trees.

In other words, every time you enjoy a nice, juicy burger, that's the carbon equivalent of driving your car every day for a month.

Eating Away More Than Just Grass

Soil erosion is a serious environmental and public health problem, "imperiling future human food security and environmental quality," researchers wrote in the journal Environment, Development and Sustainability.

Around a third of the world's land is used for grazing or to grow crops to feed cows, the WWF says, and with that area increasing further to supply meat demands, soil erosion is becoming a concerning side effect.

When the organic matter in soil washes away, its potential to produce life diminishes, thereby affecting plants, animals and microbes that depend on it. And erosion doesn't just cause irreparable damage in terms of biodiversity.

According to the Food and Agricultural Organization of the United States, food availability per capita has been declining for two decades. Although some find this hard to believe given that food productivity is increasing in certain areas, soil is eroding in others, diminishing resources and placing a heavy burden on still existing, arable land.

"Beef production isn't going to decline. So we urgently need to improve how production takes places and how we use land," Petre said in the statement.

Stay Off the Beef

According to the CBD, the production of beef, poultry, pork and other meats tripled between 1980 and 2010 and will likely double again by 2020. The world is home to seven billion people, and their hunger for beef is already taking a toll on wildlife, habitat, and resources and the climate. And not surprisingly, Americans eat more meat than anyone else.

By eating less or no meat (no, we're not saying you have to become a vegetarian), we can simultaneously get healthier and protect the planet.