It's that time of year when the UN climate jamboree comes to town, that annual melting pot of politics, science, and indecision. On this occasion it's in Lima in Peru, apt as here the effects of climate change are keenly felt.

Our coverage over the next two weeks is going to take us from the disappearing tropical glaciers of the Andes down into the heart of Amazonia and a logging hub on a tributary of the Amazon.

Along the way we'll speak to the people directly affected by a warming world as well as those who are contributing to it, by tearing down the carbon gulping forest.

We'll meet indigenous leaders and their people and hear what they make of the arguments in suits going on in a huge conference hotel in Lima.

It has to be said for once, a degree of optimism is in the air. And here at Al Jazeera, we're going to see if it lasts.

This round of talks is particularly important because negotiators from 195 countries simply must lay down rock solid foundations, so that in Paris a year from now, a globally binding treaty on how the world is to deal with climate change, will be signed, sealed and delivered. Fail - and all bets are off over a unified response.

The agreement we currently have is the Kyoto Protocol which came into force in 2005. It's a flimsy treaty that the US never ratified, didn't include developing nations like China and India and one which some countries later withdrew from.

This will be Climate Treaty Mark 2, and the goal is for all, developed and developing nations alike, to back it. It will come into force from 2020.

The stakes are becoming more evident each year. Mean global temperatures have risen by nearly 1 degree celsius since the industrial revolution, and that's kickstarted a planetary riposte.

High tides are getting higher, seas are warming and becoming more acidic, there are super-storms many believe are attributable to climate change and amped-up heatwaves and wildfires. And levels of greenhouse gases are rising faster than ever.

The aim is to keep the average temperature increase below 2 degrees celsius. Warming beyond that they say, will prove extremely challenging for our population of seven billion and growing, with many hundreds of millions pinned down in cities on shores of rising seas. To say nothing of the threats to the planet's astonishing and fragile ecosystems and indeed our own agricultural output.

So we need to do something. Hello Lima.

'A good start'

There's more hope this time because of a totally unexpected US-China climate deal announced in November. This commits the US to cutting emissions from between 26 percent to 28 percent below 2005 levels by 2025 and for China to reach peak emissions by 2030.

The experts say it's not enough, but it's a good start. The coming together of the two chief protagonists has laid down the gauntlet for others to follow and has injected a new energy into the process. It's made a deal in Paris more likely.

And that's been followed up by pledges for the Green Climate Fund which aims to help developing nations cut emissions and adapt to a changing climate. Promised monies increased from $2.3bn to $9.3bn in a week. It's believed the Fund will reach its target of $10bn in Lima. But how another commitment of $100bn a year by 2020 will come into play, still needs to be thrashed out.

We must watch how developing nations like India, Brazil and South Africa respond to the mood. There's a good early sign from the former, who have just announced an intention to more than double use of renewable energy as a share of its electricity mix by 2020.

Over the next two weeks there will doubtless be a welter of mind-boggling minutiae negotiators will battle over to their last breath. But first and foremost, Lima needs to lay out the key elements of the text of the treaty to be negotiated and finalized in 2015. The bottom line is, all roads lead to Paris.