It’s down to the wire at COP21. The agreement will decide the fate of the planet.

Depending on who you talk to, the Paris climate talks can be seen in any number of ways. To many, myself included, the negotiations set to wrap up here in the next few days are historic — and will decide the fate of our planet.

To others, these talks represent an old and tired process that has simply run its course.

Whether the process is new or old, good or bad, what I can tell you is this: this time, it needs to work.

I have been writing about climate change and this UN climate process for more than a decade now. While I have spilt much ink—or many pixels—in the past about how we need a strong, ambitious and legally binding global treaty on greenhouse gases, this time around, I really, really mean it.

A similar high-stakes negotiation was held six years ago in Copenhagen, Denmark at COP15 where state leaders seemed to disappoint the whole world by failing to deliver a final global deal. At the time it was depressing, but the world moved on.

In fact, even without a deal in Copenhagen, we’ve seen the birth of a massive, international climate movement that has recently extended well beyond your typical climate advocate. For instance, over 500 institutions representing $3.4 trillion in investment dollars have committed to pull out of fossil fuels. In Canada, we elected a new federal government who ran, in part, on a strong commitment to deal with climate change and end fossil fuel subsidies and Alberta, with the third largest proven oil reserves in the world, has announced an "aggressive" carbon tax.

All of this was unthinkable just a few years ago.

But even though the amount of change we’ve seen is positive, it is still not enough.

Last month the UK's weather service announced that for the first time since the industrial revolution, the global average temperature increased by 1 degree. That might not seem like a lot, but it means some regions much more sensitive to global average temperature fluctuation (like the Arctic) are seeing unprecedented levels of warming and extreme weather.

The conventional wisdom is that to avoid the most calamitous impacts of climate change, the world needs to stay well below 2 degrees Celsius. Now, based on new scientific research, countries in Paris are fighting to keep temperatures from rising above 1.5 degrees Celsius.

If that’s our long-term climate goal, we’re already dangerously close to meeting it.

The failure to reach an internationally binding climate agreement this week would likely commit us to a path we have no desire to travel.

That said, there is a consensus growing amongst observers and pundits that there will be a deal here in Paris. But the big question is whether we will see an ambitious final deal that steers us down the right path to a fossil fuel-free future—or one that’s been watered down over two exhausting weeks of negotiations by numerous bad actors, some of which appear to only be here to prevent a strong deal from happening.

Regardless of what happens, in the next 48 hours or so we will see important history made.