I found some news stories quoting there are to be 15 major greenhouse gas emitting nations involved, but not much more detail on the related participation criteria.
I am very interested - and I think we all should be - on how a 'major emitter' is defined. 'Emissions per person' [i.e. per-capita] and/or possibly 'per unit of gross domestic product' (GDP) seem much more reasonable than country 'A' compared with country 'B' [despite the rhetoric of some politicians to that effect].
Comparing, for example, Australia with China is ridiculous in the nation-to-nation sense. But look at the two from a per-capita or per unit GDP perspective and the comparison paints a more relevant picture [referred to as the carbon-intensity]. I recommend a read of this report from from the EIA, and in particular Table 12 and Figures 85 and 86 along with the surrounding text. Note that some of the 'bad actors' frequently bashed by politicos [China, India and Brazil for example] not only have low per-capita emissions, but are also 'on or below the trend line' and projected to remain there or shift further below in the coming decades [i.e. they have low carbon-intensities]. This trend line is described as follows within the report:
In the figures, countries and regions that are plotted on the trend line produce roughly the average amount of carbon dioxide emissions per-capita relative to income per-capita. Countries and regions that appear above the trend line are more carbon-intensive than average, and those below the trend line are less carbon-intensive than average.
So any way you slice the table and figures referenced above Australia is definitely one of the 15 major greenhouse gas emitters. In fact the only way to make our contribution appear irrelevant is to revert back to the simplistic [and to this blogger completely unjustified] nation-to-nation analysis.
As an international outlier on trends of this nature, one hopes there is even more incentive for some tangible action within Australia in the near future.
One word of warning about using carbon-intensity; I believe there is a risk that by focusing on individual intensities, one may lose the big picture - that, in absolute terms, global emissions must be stabilised and then subsequently reduced. Looking at carbon-intensities only helps identify which countries to focus on first.
Finally... note the data point furthest below the trend line [as well as very low with respect to per-capita emissions] - OECD Europe [with the highest installed and operational nuclear capacity of the group]. Is it any wonder?