To start with the impact part, I think it will be made clear that every little bit matters when it comes to climate change and that half a degree matters. Look at the Arctic sea ice. Or the coral reefs who might not survive. It will strongly define our long-term legacy of sea-level.
Our parents’ generation will be remembered as the generation that started sea-level rise. Even if we limit the temperature rise to 1.5 degrees, in 300 years, the sea-level will still rise. It is up to us to decide how much. Every five-year delay in global carbon emissions peak, even if we keep within the Paris scenarios, will lead to an additional sea-level in 2300 than we have observed so far.
That is a really strong legacy. In the bigger scheme of things, there’s been a shift from whether climate change is a problem and we should do something about it in AR5 to ok, we have a Paris Agreement now, where are we headed?
Science has a new challenge; to describe the climate impacts of the different possible pathways we may be headed towards, to inform. In order to address the climate challenges, the scientific community needs to be open to how they may be addressed.
Also, what will come out of the report, is that climate action and sustainable development can go hand in hand – and be mutually beneficial.