Because it’s a bandaid on an arterial bleed of a problem and has its own host of issues (anoxia once the algae blooms die off being one of the big ones, aside from the cost of actually doing it on a global scale). Lots of discussion around whether it makes sense to do, but really for the effort to do it, and the unintended effects on the environment, it would probably be better and cheaper to just reduce GHG emissions.
They're ignoring methane, and they're stating, explicitly, that at our current atmospheric CO2, the planet historically stabilized at between +5C & +6C.
When one factors-in the added methane, 1.3ppm to 1.4ppm, at 82.5x factor, we're actually between +8C & +9C planet-equilibrium-temperature for our current atmosphere.
-4C put 2 miles thick of ice on North America: planet-degrees are BIG.
Humankind simply is either too devoutly-ignorant or too stupid to live, from the looks of it.
After it has happened, oh, then humanity'll admit it ought do something...
Utterly retarded, and the obliteration-of-billions-of-lives it is setting-up the enforcing of, is needless.
Creating an entirely new industry “for the economy” is the reason this is even being contemplated. If you care more about the economy than the planet you live on and the people you share it with, then maybe that makes sense.
Any fix on symptoms will only give the worst offenders more excuses to increase emissions. See carbon capture and carbon credits. It's already being used as an excuse to not do anything real about the problem.
It is still being studied, and we don't know the potential ecological impacts. Estimates are that it might help sequester a meaningful amount of carbon, but only maybe 1/10 what needs to be removed by 2050.
I apologize because I don't have a source in mind, but my recollection from studying this in grad school (which was admittedly about a decade ago) was that sequestration was one of the hardest parts of this. Creating a bloom of algae was feasible, but even if we ignore a lot of other ecosystem management complications that others have pointed out, there wasn't a reliable mechanism to convert a bloom of algae into a long-term carbon store.
I could be mistaken here. I'm open-minded towards this kind of geoengineering. But I'm also very skeptical that if this could work, it could do so at a rate that would enable us to continue burning fossil fuels at scale, and there is a strong base of support for this technology among people with that attitude.
The hope is the phytoplankton are in an area where iron is scarce and they die and sink to the seabed. One experiment in 2009 ended up with zooplankton consuming the bloom, so it has definitely failed at times.
Yup, we already know what we should be doing, stop using fossil fuels. The IPCC took into account carbon sequestration in their models, they said we should invest in renewable energies and eco-sufficiency (not sure if it's the right word, but they chose "sobriété" un french)
CO2 emissions are not the only problem with burning things for power. Air polution causes an estimated 3.6 million deaths annualy (thats like world war 2 every 20 years), with the bulk of those (2.1 million) being caused just by ultrafine soot and ozone from burning fues. Additionaly, burning coal produces huge amount of ashes that are full of toxic heavy metals, in quanties that are near impossible to safely dispose of. Most of this ash just gets pilled up, where it it gets blown into the enviroment. (Fun fact, these ash piles are radioactive from naturaly occuring uranium and thorium)
The only way out is to stop burning things as fuel.
Well... there are more consequences than that... Earth is heating up, which change the amount of rainfalls, where they occur, also reducing the ice sheet in the mountain for example. This would provide less freshwater. Less freshwater will reduce agriculture output, which could bring famine. People will migrate because they are living in unlivable places, and this may bring civil unrest.
Yes we should stop burning fuel, learn how to produce food wirhout relying on fossil fuels, learn how to live wirh less.
It could change the pH of the oceans, making it harder for anything to live there. Plus, it might not store the CO2 for longer than 1000 years, which doesnt really solve the issue (I have a source for that somewhere, I think it was the IPCC).