21 years ago, smart people said global warming would change our world. They were right.

In June 1992, the leaders of 154 nations gathered in Rio de Janeiro.

They signed a pledge to reduce their greenhouse gas emissions to prevent global climate change. Two years later, those pledges became the United Nations Framework Convention on Climate Change, solving the issue of global warming completely and letting the world get on with the important business of developing actual hoverboards (#justsayin).

No article about climate change is complete without the mandatory T-rex on a hoverboard GIF.

Except, uh, no.

Instead, governments have spent the last 21 years hammering out the details of how a global climate deal will work. After marathon talks in 2011, they agreed on a 2015 deadline. For negotiators in Paris right now, that is less than two days away.

In the meantime, the world is very different from how it was when the talks began. How different? Well...

In 1994, pop culture was so earnest and adorable.

Ace of Base had three songs on the Billboard Top 100. Everybody bought "The Lion King" soundtrack. Seinfeld was the most popular show on TV, George Clooney was still on "E.R.," and Captain Planet and the Planeteers saved the world from Hoggish Greedly every Saturday morning.

In 1994, everyone wanted "The Rachel."

Stylish people — and not just Tour de France riders — were excited to wear spandex bike shorts in public. People, like The Rock, unironically sported fanny packs, stonewashed denim vests, and jeans that did up with little padlocks instead of a button fly.

Seriously, the Rock wore that. Image via The Rock/Facebook.

You probably knew at least one person who tried to wear their wear their pants backwards.

In 1994, Bill Clinton was in the second year of his first term as President of the USA.

Vice-President Al Gore had helped implement some U.S. climate policies but hadn't yet made "An Inconvenient Truth" or won the Nobel Prize. Meanwhile, 1994's Barack Obama was a community organizer, an associate at a Chicago law firm, and still two years from being eligible to run for president at all. Oh, and Mark Zuckerberg was 10, which was fine because most people could only access the Internet via dial-up connections, and a "social network" was what your grandmother called her friends who came over to play bridge.

In 1994, the global concentration of CO2 was around 356 parts per million.

As of last week, it is officially 400 parts per million worldwide. Here's why that's bad.

In 1994, 5.6 billion people lived on Earth — 1.7 billion fewer than today.

Image via Andres Ubierna/Flickr.

China and India were developing nations, just starting to embrace industrialization. Nelson Mandela was elected president of South Africa, just six months after apartheid ended and four years after being released from a 27-year prison sentence. Poverty, inequality, and disease were huge issues across the developing world — a sad constant that remains today.

In 1994, we didn't need new colors to map extreme heat in Australia.

Or new classifications for superstorms like Haiyan in the Philippines or Sandy in the U.S. The first small island states were still 15 years from needing to evacuate their homes from rising sea levels. We knew about the hole in the ozone layer, but we hadn't yet discovered how warming seas were bleaching and dissolving coral reefs or that plastic pollution created the Great Pacific Garbage Patch.

Say hi to the giant blue hole in the ozone. Image via NASA/Flickr.

If you were a baby born on the day the UNFCCC came to be in 1994, you probably wouldn't be reading this right now because you'd be at a bar somewhere buying alcohol legally.

Think about that — in the time it has taken world leaders to agree on what to do about climate change, a child has grown from a tiny chubby-cheeked blanket burrito who doesn't know it has a nose to an adult who can vote, join the Army and graduate from college in a few months.

In the past 21 years, we've seen great advances in renewable energy technology.

Fancy solar panel doing its thing. Image via The ReGeneration/Flickr.

Hybrid and electric cars are freely available. Business, industry, and government are all adapting to make climate change part of their current operation and future plans. Taking action on climate change inspires global mobilizations, music, and movies.

At the same time, we've seen the real impacts climate change is already making on our planet as extreme weather drives droughts, storms, and sea-level rise, sending species to extinction and displacing tens of millions of people.

So while it may have taken two decades to get here, the world has never been more ready for climate action than it is now.