There is a great way to store, transport, and use hydrogen:

Bind it to various length carbon chains.

When burned as an energy source the two main byproducts are carbon dioxide which is an essential plant growth nutrient, and water which is also essential to plant growth.

Environmentalists will love it!

And they can prise my turbo diesel engines from my cold dead hands.

Carbon Dioxide is a greenhouse gas, which makes the world warmer on average. It also lowers the PH levels of the oceans.

If the oceans die, its very likely that many or even most humans will also. As a human I am pretty strongly opposed to dying, but thats just, like, my opinion man.

Factually correct, but you also missed the joke.

It was only kinda a joke. It's a joke in the same way that uncle on Facebook makes jokes. You know the one.

Take The Great Barrier Reef for example.

There’s more of it now than in the reefs recorded history.

Well, 2022 data:

https://www.aims.gov.au/information-centre/news-and-stories/...

"The picture is complex. Recovery here, fresh losses there.

While the recovery we reported last year was welcome news, there are challenges ahead. The spectre of global annual coral bleaching will soon become a reality."

This article also mentions that a recent large recovery was due to el nino conditions

"Great Barrier Reef was reeling from successive disturbances, ranging from marine heatwaves and coral bleaching to crown-of-thorns starfish outbreaks and cyclone damage, with widespread death of many corals especially during the heatwaves of 2016 and 2017.

Since then, the Reef has rebounded. Generally cooler La Niña conditions mean hard corals have recovered significant ground, regrowing from very low levels after a decade of cumulative disturbances to record high levels in 2022 across two-thirds of the reef."

Not sure if you were trying to imply some long term recovery or that global warming didn't hurt it because the article says heatwaves were part of a many other conditions that caused massive damage

The problem is all the effort = energy you need to spend collecting carbon atoms.