But how will these INDCs fit into a global climate deal?
Paris goes more bottom-up
The Kyoto Protocol, adopted in 1997, is often considered a top-down treaty because all the rules and parameters were agreed internationally. In practice there was still a strong bottom-up element, with countries setting their own emissions-reduction targets. A true top-down treaty would begin with a collective target (say, of staying below 2C) and then derive from that each country's reduction commitment according to some internationally agreed method.
The successor to the Kyoto Protocol, the new climate agreement to be finalised in Paris, is shifting the weight further away from the top-down towards the bottom-up. INDCs are the bottom-up elements (self-determined targets) and a consistent accounting approach across the board (such as the scope and type of target, or whether credits can be substituted) could be a thing of the past. The degree to which common rules for monitoring will be part of the Paris agreement remains to be seen.
What should be included in INDCs?
The outcome of the most recent major climate talks in Lima in 2014 explicitly requested that countries:
• Include in INDCs how they plan to contribute to stabilising atmospheric greenhouse gas concentrations.
• Include an explanation of how their INDC contribution is "fair and ambitious", in the context of national circumstances.
• Consider including an adaptation component.
• Communicate in such a way that "facilitates the clarity, transparency and understanding" of the INDC.
• Include, where possible, quantifiable information such as reference years for emissions reductions, time frames, inclusions and exclusions, assumptions, and methods used for estimating greenhouse gas emissions.
Many developed countries are likely to prioritise aspects of emissions reduction and particularly those that are quantifiable. For example the European INDC targets an emissions reduction of at least 40% below 1990 levels by 2030 for domestic action. Switzerland's INDC targets a reduction of 50% below 1990 levels by 2030, but includes the use of international market mechanisms.
In contrast, many developing countries are calling for INDCs to provide information on adapting to climate change, financial support needed or to be given, and technology transfer.
In response to these differences of opinion, German-based think tank Climate Action Tracker is pressing for governments to ensure that INDCs are based on "rigorous and scientifically sound emissions information". At the same time, there is a recognition that countries differ in their abilities and capabilities to provide measurable, reportable and verifiable information.
Alongside this discussion on content, there is also an ongoing debate on what should be the legal forms of both INDCs and the overarching Paris agreement.
Keeping warming below 2C
As the "i" in INDC indicates, INDCs are proposals but are not yet set in stone. These proposals will be assessed collectively to determine the resulting global effort.
In all likelihood the collective effort will be insufficient to stay within the 2C guardrail.
So then how will INDCs help a deal to keep warming below 2C? It is anticipated that in Paris countries will agree on an assessment process to compare INDCs, with a view to "ratcheting up" the effort. This iterative process aims to produce ambitious collective global action before 2020, when the agreement will come into force.
It is not yet clear how the INDCs will be assessed, though. Will only emissions reduction targets be counted? How will unquantifiable targets (such as peaking emissions before a certain date) be measured? How will targets that are conditional, for example on international finance, be considered? Will emissions reduction and financial support needed and proposed be assessed in tandem? Will all elements of the INDCs (which will unavoidably differ between countries) be assessed? And if so,how? Discussions on these sorts of issues are expected in the lead-up to and in Paris.
Another big question is whether major economies will indeed strengthen their emission reduction commitments in response to the collective effort being deemed insufficient.
Anita Talberg is on an Australian postgraduate award PhD scholarship.
Malte Meinshausen receives funding from the Australian Research Council, advises the German Ministry of Environment and other national and international bodies on climate policy and science.
He was formerly a founding director of Climate Analytics, but is now only affiliated with The University of Melbourne and the Potsdam Institute of Climate Impact Research.
He is the director of the Australian-German College of Climate & Energy Transitions.
This article was originally published on The Conversation. Read the original version and sign up for Element's newsletter for related reading.