solo

I am not really sure I understand what you mean. Of course 0.5°C is very important, but to my understanding, the Paris Agreement is really not going as planned.

As the official deadline passes for countries to submit their revised Nationally Determined Contributions (NDCs) under the Paris Agreement, only 13 of the 195 parties have done so. Alarmingly, this group includes just five developed countries, which are required to lead the way on climate action.

Under the Paris Agreement, every country must update its national climate action plan every five years. These NDC plans outline how nations intend to reduce emissions and adapt to climate impacts to limit global warming to 1.5°C above pre-industrial levels. This year’s submissions should extend their new NDCs to 2030 and outline new objectives for the period up to 2035, setting the tone for a decisive decade of climate action.

[source]

Edit: Since the above article dates a few months back I searched for something more updated and found the perfect link: NDC Tracker

It looks like the IMO's pledge to reduce emissions by at least 20% is totally feasible. At least according to the following recent study

Reducing travel speeds and using an intelligent queuing system at busy ports can reduce greenhouse gas (GHG) emissions from oceangoing container vessels by 16-24%, according to researchers. Not only would those relatively simple interventions reduce emissions from a major, direct source of greenhouse gases, the technology to implement these measures already exists.