My understanding is kelp forest will only grow on the continental shelf, so forget the whole surface of the ocean stuff.
Why will it only grow there? Tim Flannery is a biologist.
Then you have to add in the fact that Kelp do have water temperature and sunlight requirements that limit how much of the ocean shelf could viably be used to farm kelp.
We would obviously build floating frames that they could attach to, keeping them up in the sunlight zones even in deep waters.
Third, not all wildlife does well in kelp forest regions, so you need to reserve good size chunks of the shelf for sea grass where the Manatees can graze and all the other variations that you get in the continental waters.
Of course! Respect the mangroves and wetlands and many, many other threatened ecosystems. But build the kelp out in deeper waters - if possible. That's the key. That's what we have to establish. Why would a biologist like Tim Flannery put so much emphasis on something that was intrinsically impossible?
Put all those factors together and MAYBE you can grow Kelp forest on 10 percent of the continental shelf or about half a percent of the total ocean surface.
But we haven't established the first, main factor - that kelp cannot be intentionally farmed in deep waters - with peer reviewed sources.
That is still an admirable thing to do because Kelp is a great food source, not just for human beings but also for grazers like cattle and omnivores like swine.
Yes, there is even a strand of kelp that cuts cattle methane burps by 99%! A special seaweed can be fed to cows to supplement their diet a little with drastic results: it eliminates their methane burps, which have been shown to lose 15% of the cow's potential growth gains!
https://goo.gl/J27gw0Counting on it to replace all fossil fuels? Not so much.
I'm not. I'm counting on high EROEI breeder reactors that eat nuclear waste, and can generate all the diesel we need from the CO2 and hydrogen in seawater. (Recyclable boron powder is another contender as an energy carrier to replace oil).
https://eclipsenow.wordpress.com/recharge/So this is not some desperate fallback. We have dozens of today's designs of nuclear reactors that can keep us going, and dozens of viable designs of future breeder reactors to eat all today's waste. That's not the problem here. I'm just asking... what if? What if I've been wrong for 6 years, and nuclear is NOT the only way? What if a renewable grid could actually be backed up by a carbon-tax funded seaweed industry that produces fuel AND food?
Bottom line?
I haven't found a peer-reviewed source that says we
cannot grow kelp in 9% of the world's oceans.
Dr James Hansen recommends breeder reactors that convert nuclear 'waste' into 1000 years of clean energy for America, and can charge all our light vehicles and generate "Blue Crude" for heavy vehicles.
https://eclipsenow.wordpress.com/recharge/