It will be fractious and frustrating and it won’t “solve” the problem. But the Paris climate summit that starts on Monday is likely to be characterised as a success anyway.

That’s because negotiators have reset what qualifies as succeeding, and not just to allow world leaders to pat themselves on the back. Counterintuitively, demanding less might, in the end, achieve more than previous ambitious meetings that ended in failure.

For more than 20 years, the world has been struggling to tackle a collective problem that costs a huge amount to solve but immeasurably, unthinkably more to leave unattended.

The UN process has abandoned the old approach of trying to impose on each nation a fair share of the global job of reducing greenhouse emissions and is instead allowing countries to pledge what they feel able to contribute and are prepared to defend as a reasonable contribution to the accepted global goal of limiting global warming to 2C.

We know already that the promises won’t get there. The US president, Barack Obama was upfront about this when Rolling Stone accompanied him on a trip to Alaska in September.

“Let’s stipulate right now, whatever various country targets are, it’s still going to fall short of what the science requires. So a per cent here or a per cent there coming from various countries is not going to be a deal-breaker.

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“But making sure everybody is making serious efforts and that we are making a joint international commitment that is well-defined and can be measured will create the basis for us each year, then, to evaluate, ‘How are we doing?’ and will allow us, five years from now, to say the science is new, we need to ratchet it up, and by the way, because of the research and development that we’ve put in, we can achieve more ambitious goals,” he said.

The president was on the money. Even if every pledge is met (they have so far been received from 166 countries responsible for more than 90% of the world’s emissions) global warming will still hit at least 2.7C and might even rise to 3.5C – an outcome science tells us will still cause Australian cities like Perth to experience 50% more days with temperatures over 45C, reduce winter and spring rainfall in the southeastern Australian food bowl, increase the frequency and severity of droughts and increase the number of days of extreme fire danger in southern eastern Australia. Without an agreement, those impacts would be worse.

The idea of the Paris agreement is to lock in those first pledges and then, over time, push countries to each do a bit more to make up the difference. In an interesting speech available on the Department of Foreign Affairs website, Australia’s ambassador for the environment, Peter Woolcott, argues this new bottom up approach is a recognition of the limitations of multilateralism to deal with common problems like climate change in a world where the location and very nature of power is changing.

So here are seven things to know about what Paris could do, and what it means for Australia.

1. An ever-tightening domestic target

The Abbott government said it would reduce Australia’s emissions by between 26% and 28% of 2005 levels between 2020 and 2030. Malcolm Turnbull has not changed that target. Analysis by Climate Action Tracker rates that promise as “inadequate” and so does Labor, which says it would aim for a 45 per cent reduction over the same timeframe. The government claims it is in “the middle of the pack”. But while Australian debate sometimes paints that number as static - a done deal - the Paris agreement sees it as an initial offer. The new agreement will build in a process to ratchet up the contribution, proposing a global “stock-take” even before the 2020 start date and regular national reviews every five years. The Australian government has backed the idea of five yearly reviews.

2. Maybe a more ambitious international target

The draft agreement – which instead of getting honed down at the final pre-Paris negotiating session in Bonn, Germany, actually grew to 51 pages, including, as one of a thicket of unresolved “options” on every topic, that the world should aim for net zero emissions by 2050, or maybe 2100, and, at the insistence of the US and developing countries, the goal of “decarbonisation of the global economy over the course of the century”. These somewhat vague long-term goals are intended as flashing light signals to business and to people (like former Australian prime minister Tony Abbott who said coal use would go “up and up and up for decades and decades to come”) that the world must gradually wean itself off fossil fuels. At the recent G20 meeting Turnbull signed on to a call for Paris to “establish a durable platform for limiting global temperature rise to below two degrees”. Hunt has spoken of Australia achieving net zero emissions by the end of the century. The Labor leader, Bill Shorten, has set a goal of net zero emissions by 2050.

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3. Check ups – rules for monitoring, reporting and verification

The targets pledged in the Paris agreement will not be legally binding because if they were it would require US senate ratification with a ⅔ majority and that won’t happen and then everything would stall. But it will include rules about checking and reporting what countries are doing, so laggards can be “named and shamed” and so countries can be confident everyone else is doing their bit before agreeing to “rachet up”. Australia is lobbying for clear, strong monitoring rules.

4. The same rules for all

The central tension in international climate talks ever since Rio in 1992, where the UN Framework Convention was signed, is the developing nations’ fear that rich countries will thwart poor countries’ economic development in order to solve the climate change problem the rich countries’ development has created. In fact the convention specifically divides the world into developed and developing country lists, with very different obligations. But the global economy has changed dramatically since then, and Paris aims to reflect those changes. Australia argues that the same transparency rules must apply to all.

Woolcott sees the change as “a microcosm of the problems of the wider UN”.

“We are between multilateral worlds – the old world dominated by the West can no longer dictate nor finance alone the solution. The new world has not yet arrived and the emerging powers are reluctant to take on responsibilities which might compromise their freedom of manoeuvre and economic development.”

But finance from rich countries is likely to be the trade-off for agreement to universal obligations by developing countries. Which brings us to...

5. Requests for cash

By which we mean an agreement for countries and companies to provide at least $100bn a year by 2020 to poorer countries to help them mitigate and adapt to climate change. This is likely to be one of the hardest-fought parts of the Paris Agreement because developing countries are demanding a specific, and higher, figure after 2020, and there is dissent about how much aid should come from countries like China, which recently pledged $3.1bn. So far, according to the Organisation for Economic Co-operation and Development, the total amount promised is around $60bn a year. At last year’s US conference in Lima, Peru, Australia promised $200m to the Green Climate Fund, an organisation then prime minister Abbott described as “the Bob Brown Bank on an international scale” – a reference to the domestic Clean Energy Finance Corporation, which Abbott unsuccessfully sought to abolish. Australia has since resumed its position as co-chair of the fund, a move seen internationally as a sign of a more cooperative attitude. But Australia will still be under pressure to provide more money. Non-government organisations say we should be tipping in about $1.5bn. Given the government’s focus on reining in spending, that is unlikely, but it may look for ways to leverage more private sector spending.

6. A please explain

If Paris succeeds in its modest aspirations, the Turnbull government will be under even more pressure to explain how its Direct Action policy can meet the target, and the tougher ones to follow. The government has promised a review of the policy in 2017, after the next federal election. Business has noted the discrepancy between the targets and the capacity of existing policy and assumes tougher rules are coming. While the Australian debate has been obsessed with the alleged costs of reducing emissions, business has long understood some costs are inevitable and is craving the investment certainty of a stable and workable policy – and many business groups are again calling for a carbon price. And in the lead up to the 2016 election, Labor will also come under pressure, because so far it hasn’t announced a detailed policy at all – only an intention to reintroduce some kind of emissions trading scheme.

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7. A long road ahead

This Paris agreement will be the start of a long, long process. It feels as though these talks get nowhere fast. In 1992 I reported on the Rio de Janeiro meeting, where leaders signed the framework convention promising to take some kind of action. In 1997 that turned into concrete commitments under the Kyoto Protocol to reduce emissions by 2012 with the aim of cutting emissions by 5%. But for many years it was not ratified, and even when it was, countries that failed to meet their targets met no sanction. In 2009, the global talks tried to lock in the next step in the process – promises by both developed and developing countries to reduce emissions – but the chaotic Copenhagen meeting ended with a loose accord, not tied into the UN process until the following year’s meeting in Cancun, Mexico, and countries like Australia – which had nominated a target range (reducing emissions by between 5% and 25% by 2020) stuck with their low-ball offer.

Now the Paris pledges will try to coax the world along rather than shouting and demanding. That may turn out to be more successful. But even if it is, it’s the start – not the end – of the process.

Paris by numbers

40,000 – the number of people attending, including 25,000 delegates and 3,000 journalists

147 – the number of world leaders attending “leader’s day” on Monday, including Obama and Turnbull. The order in which they will speak at two consecutive speed-speaking sessions can be found here

196 – the number of countries represented

10,800 – the number of police deployed for the summit – 8,000 on the borders and 2,800 at the venue

Seven – the number of gases covered by the Kyoto Protocol: carbon dioxide (CO2); methane (CH4); nitrous oxide (N20); fluorinated gases (PFC, HFC, SF6); and, since 2013, nitrogen trifluoride (NF3)

€170m – the cost to the French government of hosting the talks.

2.7C – the warming that will still occur if every country keeps its current promises.