'Green' Hydrogen Bomb

The UK government have reportedly been converts to the idea of developing 'green hydrogen' as a non-environmentally damaging fuel to power cars etc (https://www.theguardian.com/environment/2020/oct/03/green-hydrogen-from-renewables-could-become-cheapest-transformative-fuel-within-a-decade). It seems, however, that their preferences are a little dated. They advocated using natural gas or gasified coal to provide power but combining this with carbon capture and storage to prevent carbon dioxide being released into the atmosphere. The hydrogen is essentially obtained from water by an electrolytic process. When it is 'burned' water is the sole product. This basic idea seems to have been overtaken by faster than expected Chinese developments of electrolyser systems (they can generate hydrogen, using renewable energy sources, 80% cheaper than the originally envisioned devices). An example of the technology is provided by the Australian Asian Renewable Energy Hub, a proposed development at Pilbara in Australia. This would consist of 1,600 wind turbines and 78 square kilometres of solar panels that would provide 16 gigawatts of power to drive hydrogen electrolysers. The generated hydrogen (hydrogen is very explosive) would hopefully be safely transported to other countries in tankers in the form of 'green ammonia'. The hydrogen can easily be extracted from the ammonia. I would hate to think,however, what a tanker disaster, releasing enormous volumes of concentrated ammonia, might do to the oceans?