Wow! How did that happen? The United Nations has just agreed the first ever universal climate deal - and it's better for the global environment than anyone had dared hope for.

For once, believe hyperbole: this is the most significant international agreement since the establishment of the United Nations in 1945.

Here's just 5 things from Paris that make this so good:

1. In the run up to Paris, more than 180 countries made commitments to cut emissions significantly;

2. They agreed a surprisingly strong 5 year review or "ratchet" mechanism for bolder future commitments to cut emissions further;

3. They backed a new long term goal to make sure global warming stays "well below" 2 degrees Celsius, heading to greenhouse gas neutrality in the second half of this century - meaning the effective ending of fossil fuels;

4. Increased support for poorer countries to help them - whether in the low carbon transition or in adapting to climate change impacts already with us;

5. Huge progress on the "rules" for how we decarbonise the world, including key technical stuff on audit and accounting and crucially, strong transparency rules, so we know what countries are actually doing.

And if you don't believe me, listen to the majority of NGOs: from Greenpeace to Christian Aid, there's been a huge welcome. And those businesses and financial institutions who take climate seriously are predicting a massive rise in investment in clean green technology.

That means we will go green more quickly and more cheaply.

Of course, it's not perfect: I would have liked larger commitments to cut emissions, and to cut them earlier; I would have liked the first mandatory review to happen earlier; and so on.

But to quibble today, is to miss the big picture. So if it's a climate change denier trying to dismiss this, or even a green NGOs carping about this or that, don't be fooled: this is genuinely historic.

So I confess I partied last night here in Paris. And whether it was Christiana Figueres, the amazing woman who's led the UN Secretariat on Climate Change to this point, or Todd Stern, the wise and experienced US lead climate negotiator, or a range of grassroots activists, the mood was euphoric.

Some at the party had spent over 20 years' working for this day!

Of course, Liberal Democrats have been campaigning for this day for over 20 years too.

So let's enjoy it. And let's be proud of our green record - whether in councils across the country, or when we've been in Government in Scotland, Wales or Westminster, or when we've had fab MEPs like Chris Davies, Fiona Hall or Catherine Bearder, leading the cause in the European Parliament.

There's lots more to do - here in the UK and across the world: and I'm planning to write about that next week. But for now, for so many reasons, let's just say "nous sommes Paris".

* Ed Davey was the MP for Kingston and Surbiton and Secretary of State for Energy and Climate Change.