What will be the focus of COP26 climate conference? The multiple agendas are really quite complex and involve some very technical talks (e.g. article 6) but one of the key things countries want is to make sure action happens now - this year and next - not vague promises for future.
Sources say one hope is an agreement on countries updating their nationally determined contributions (NDCs) - which set out actual plans to reduce emissions up to 2030 - every two years instead of five.
This is seen as critical because as we know, scientists say we need to halve emissions by 2030 to be on track to keep heating below 1.5°C.
And yet the current plans get us nowhere near that. To put it in perspective - that means we need to be taking 28 gigatons of greenhouse gases out of the atmosphere by 2030- all the plans so far will take out four gigatons, leaving a massive gap.
But there are possible reasons to be hopeful - for a start look at the hugely positive shifts, like cost reduction in fossil fuels, that in turn massively increase commercial incentives for countries to act.
And we’ve come a long way in recent years - 80% of world economy is now covered by net zero ambition (when the amount of greenhouse gases emitted is the same as that taken out from the atmosphere).
But of course these ambitions are often political promises (and as we see in America, politics can shift wildly). The problem is they cannot be legally enforced, although it happens in some countries.
The G20 countries that are really behind on this are Brazil and Mexico, whose new country NDC plans went backwards, Australia, who stood still, and China, where progress was minimal.
India has yet to update its NDC but UK sources are hopeful Modi will want to make a splash.