Lego wants to change everything about everyone's favorite toy brick without anyone noticing.

If that sounds like some kind of riddle, it partly is -- especially for the research team tasked with delivering on the promise. Lego is joining the ranks of Starbucks and McDonald's by reducing its dependence on petroleum-based plastics.

Except Lego want to go a million steps further. The company is vowing to construct its toy blocks entirely from plant-based or recycled materials by 2030, according to New York Times. Here's the kicker: They haven't exactly figured out how to do it yet.

But if they do, Lego will completely revolutionize the future of their company -- and its core product. Lego currently produces about a million tons of carbon dioxide each year, and this would gigantically slash their carbon footprint.

When plastic is the product

If Lego succeeds, they'll make eliminating plastic straws look like child's play. The plastic straws served in fountain sodas and iced coffees are a blip in the amount of packaging that McDonald's and Starbucks use.

For Lego, plastic is their product. All Lego toy blocks are made with a strong, resilient plastic called acrylonitrile butadiene styrene (ABS). Their composition has hardly changed in over 50 years, the Times reports.

Revamping the material will be no small feat for Lego. Their new sustainable-based toy blocks need to look and act exactly like today's Legos. The future of the company depends on it. It's unlikely anyone will want to buy a less-performing product, even if it is better for the environment.

To start, the company began rolling out some plant-based Lego components. Earlier in 2018, the company announced that "botanical elements" -- a.k.a. Lego trees, leaves and bushes -- would be made from plant-based plastic sourced from sugarcane. These are more like accessories, and not the company's bread and butter.

But the bricks themselves have not yet gotten their sustainable makeover. Lego is working on it. It's just a totally different challenge, and somewhat daunting.

The biggest hurdles to sustainable Legos

Why is using plant-based materials in Legos such daunting task? Imagine the humble Lego brick. Or actually, this: Imagine what it feels like to step barefoot on a Lego block. Let the pain of the small, sturdy 1.6mm toy brick painfully sink into your foot. Even though it hurts, you can't deny that Legos are basically indestructible.

Legos can withstand countless hours of being stacked on top of each other, only to be ripped apart in a child-like frenzy. They survive being thrown into giant bins and dumped out. They survive being stepped on.

All of that is thanks to their strong, plastic-based material. Unfortunately, most recycled and sustainable materials are too soft and malleable. They cannot withstand the same wear and tear of today's plastic Lego blocks.

Lego has experimented with firmer materials, but sometimes they break, leaving sharp edges -- which absolutely won't fly with children's toys. Keeping the trademark Lego colors is a challenge, too. The bright reds, blues and yellows often look washed out when plant-based materials are used.

Even though Lego has not yet found the right material to fulfill their promise to make sustainable bricks by 2030, Tim Brooks, the environmental responsibility VP, said they won't stop trying until they get it right. Lego emits a million tons of carbon dioxide each year. A third of this comes the raw materials its factories use to produce Legos. Brooks told the Times the company is committed to making a toy that doesn't jeopardize children's futures.