Meat consumption is considered one of the biggest climate-change culprits. The animals themselves release emissions - yes, we're talking cow farts - and livestock farming consumes vast resources, including land and water.

A study by the Future of Food project at the University of Oxford found we could save up to two-thirds of greenhouse gas emissions if we ate less meat and more fruit and veg.

The good news for burger lovers is the study talks about eating less meat - not none at all.

So when you do treat yourself to the occaisional burger, how do you make sure you're making the most sustainable choice?

Two German startups have come up with a novel business model: They tell you everything you need to know about where your meat comes from - and ensure waste is kept to a minimum.

The ancient trade of butchery has caught up with the digital age. 

Crowd-butchering?

The concept is simple: A cow or pig is only slaughtered once all its meat is sold.

In fact, it's not really a new idea. It harks back to the days before factory farming delivered shrink-wrapped cuts to your local supermarket, and countryfolk banded together with family or neighbors to buy an entire animal. 

Only now, your share of the beast is just a click away. 

KaufneKuh - meaning "buy a cow" in German - and Geteiltes Fleisch - "shared meat" - only offer meat from small farms with relatively sustainable practices.

You can chose between a 3.5-kilo (7.7 pounds) or 7-kilo pack, of steaks, burger patties and minced meat. All packages are the same to ensure all parts of the animals are used and nothing is wasted.

Then, you just have to wait until the rest of the animal is sold. The average cow is ready for the abattoir when between 35 and 70 customers have claimed its flesh.

Then it's slaughtered, processed and delivered to your doorstep. 

Crowd-butchering might not be for the spontaneous carnivore. It can take up to four weeks from ordering before you finally get that steak in the pan. 

Know your steak

Both startups say they're responding to the need for greater transparency in the meat industry. Consumers, they believe, should know what they're getting.

Dennis Vetter, founder of Geteiltes Fleisch, says it's almost impossible to find out where the meat in your local supermarket comes from. 

"That's why I had the idea to offer high-quality meat to customers in a completely transparent manner - from birth to plate," he told DW. 

Crowd-butchering customers can see which farm the animal lives on, and what it's fed on, before they order. 

You can even find out the age, sex and breed of cow - which might be too much information for some meat-eaters. But knowing the meat on your plate lived a good life can ease the conscience.

Berend te Voortwis, founder of KaufneKuh, says he only sells "happy cows."

"A happy cow for me would be a cow that had a decent life, walking outside, having a good variety of vegan food, and only given medical treatment when the animal is sick - and not in advance," he says.

Eating less, but better

So could butchery on demand be the future of sustainable meat consumption? 

It's a step in the right direction, says Markus Wolter, animal husbandry expert at WWF Germany.

Wolter has researched the environmental impact of the meat industry extensively. On average, Germans eat more than 1 kilo of meat per week. And that isn't healthy for them - or the planet.

Health guidelines recommend between 300 and 600 grams of meat per week. From an ecological point of view, WWF says we shouldn't eat more than 350 grams per week.

That's two burgers or one classic Sunday roast.

Wolter believes crowd-butchering could help to reduce meat consumption by making us think more about the life and death reality behind the chops on our plates.

"The consumer realizes what meat consumption entails, that animals are born, bread and butchered for us," he says. " It's a great way to promote conscious consumption."

And consumers have the power to shape the way meat is produced. Meat lovers have to be prepared to pay more if they want to enjoy a burger without harming the environment, says Geteiltes Fleisch founder Dennis Vetter.

"As long as people are not prepared to question the living conditions of animals in intensive livestock rearing and, most of all, are not prepared to pay a fair price for high-quality products, the big producers won't change anything."