Nightmare Scenario: Chemistry will destroy planet Earth sooner than you think

[NanoMachine]

Right now chlorophyll in plants uses solar energy to convert carbon dioxide and water into food.

One of chemistry's holy grails is to use solar energy to split water into hydrogen and oxygen. We will get clean fuel at a very low cost.

I believe some form of genetically modified organism will be used to split water into hydrogen and oxygen, powered by sunlight. These organisms will escape into the environment. When they convert water to hydrogen, the hydrogen will escape to space and be lost forever. Gradually all water will be converted to hydrogen and the planet will be dead.

Is it possible?

[firebird]

Interesting thoughts Nano. If the organisms were engineered to be killed by salt, they couldn't evaporate the oceans. That would slow down the process you've outlined, but wouldn't stop it.

[jellopopsicle]

Wow... never thought of this that way! Way to kill clean energy talks lol!

But then firebird, there could be the apparition of resistant strains to salt too!! Oh noo!

[KathChem82]

hey nano! do you have some literature sources of your ideas? i think i want to expound my ideas on the possibilities of all these things happening. Or maybe just a basis.

[NanoMachine]

Originally Posted by jellopopsicle

But then firebird, there could be the apparition of resistant strains to salt too!! Oh noo!

Yes, the law of unintended consequences.

Originally Posted by KathChem82

hey nano! do you have some literature sources of your ideas? i think i want to expound my ideas on the possibilities of all these things happening. Or maybe just a basis.

No, it's something that came into my head. I was thinking about how to generate hydrogen at lowest cost and how it would be great if we could do it for free. Then I thought about how all our food is made by plants using just sunlight. Then I thought it would be great if we could engineer an organism that used energy from sunlight to split water. Than I thought what a disaster it would be if this organism ever escaped into the natural world.

[Paul Robbins]

It's an interesting idea. If the organism could only operate at human body temperature, then it should present no danger if it escaped.

[KathChem82]

Well Nano I think that would not be such a good idea. I mean the escape of that possible organism. Then it would convert all the water in the world to hydrogen and oxygen. Hmmmm. These microorganisms can go uncontrollable. Maybe we should just stick with electrolysis of water to produce hydrogen. This one can definitely be controlled.

[KathChem82]

Hey! I just learned that there are bacteria that can produce hydrogen. They do not need to split water to do that. They simply convert the heat from the sun to hydrogen. They are called cyanobacteria. This is more efficient than using solar cells. The heat from the sun can produce hydrogen that can be used as fuel. However the concentration of that heat from the sun on the earth's surface is just low. To collect appreciable amount of heat for hydrogen production, large areas should be covered. These cyanobacteria on the other hand have all the natural capacity to produce hydrogen. They are photosynthetic hydrogen producers, in vivo.

[NanoMachine]

Thanks Kath. I did not know this. It looks like my idea wasn't original. The cyanobacteria seem to either biophotolyise water (so there's still the scary possibility I was worried about) or hydrocarbons.

Under certain conditions, however, instead of reducing CO2, a few groups of microalgae and Cyanobacteria consume biochemical energy to produce molecular hydrogen. Hydrogenase and nitrogenase enzymes are both capable of hydrogen production.

Hydrogenase, the enzyme responsible for this hydrogen production, catalyses the following reaction:

2H⁺ + 2X_reduced <=> 6 H₂ + 2X_oxidized

The electron carrier, X, is thought to be ferredoxin. Since ferredoxin is reduced with water as an electron donor by the photochemical reaction, green alga are theoretically water-splitting microorganisms.

http://www.fao.org/docrep/W7241E/w7241e0g.htm

[KathChem82]

Them those "certain conditions" have to be avoided then to prevent the splitting of water. This way, reducing power will not be coming from water but from other materials such as starch.