Pain killers often cause side affects worse than the original pain. For example--vicodin can cause severe constipation in some folks and if they have a bad colon to start with--can kill them.

Nobody can foresee all side effects of any kind of geoengineering. And not just huge money but you would also need approvals from all countries on Earth. Imagine whenever there is drought or flood in anywhere in the world, people suing US and asking for millions/billions for the damage!

Geoengineering to combat anthropogenic global warming is wreckless and arrogant. The claims of AGW are in doubt by many, too many to ignore, especially as AGW is widely considered to be a political movement not a scientific one.
For an example of the pseudoscience of AGW consider the claims that we are approaching an irreversible tipping point. The ice cores prove that just as temperature has varied widely during Earth's history, so too has CO2 concentration. Indeed, there have been periods when CO2 levels have been ten times what they are now. Yet, here we are with a paltry 400 ppm.
How can anyone claim that Earth is at an irreversible tipping point when the self-same evidence used by the warmists prove beyond any doubt that nothing about Earth's climate or atmosphere is constant.
Geoengineering will be our biggest folly, far worse than leaving the climate to do what it does best on its own.

Global warming is a great gift for mankind, because it increases the natural resources of human living: increases the usable area for agriculture and increases corn yields. If we cool down the Earth, millions would start to starve, and wars would be started to access the natural resources. Man-made global warming is a myth, and global warming is a good news for the human race. The development of the whole human civilization was made possible by a global warming 11 thousand years ago.

I agree with D Frances "Geoengineering to combat anthropogenic global warming is wreckless and arrogant" Look at all the mistakes we've made in the past e.g. rabbits & toads in Australia, thalidomide.....the list is endless. As they say 'Sow the wind & reap the whirlwind'
Put ( use due diligence on climate org ) into Google for up to date information on the climate.

I agree totally with Rumata ,who is dead on in what is really the whole picture here. It has been discovered that the earth was approximately 18 degrees warmer in the past and this allowed large creatures such as dinosaurs and other reptiles to flourish and grow extremely large. It seems the environmentalists won't be happy until we are under another ice age and a colder climate would be very bad for us, especially northern countries like Russia and Canada.

"We really don't know the effects of geoengineering, but that is why we're doing this research. Once we have declared that our theory is sound, we'll put it into practice. After that, if anything should go wrong, we'll simply blame it on the United States (in general) and Republicans in particular. You know... pretty much like we do now when we goof up.]"

All these comments are well stated, BRAVO!
The idea of introducing a "cure" into a chaotic system of which we know little is bound to have unintended and possibly disastrous results. It seems the height of arrogance to think that we know all we need to know about the Earth's climate, and, as Rumata has clearly stated, just what is the optimum temperature? I am sure our Canadian friends wouldn't mind a little "Global Warming", and, as I sit here hiding from the outside temps of 2C in Chicago, I wouldn't mind it myself...

Equatorial desserts have high thermal emittance. This is how most of the heat escapes from the Earth. Transpiration of water in arid lands produces about 80% of AGW.

DFrancis....I agree that geoengineering is a bad option and should be avoided. However, the only people who doubt AGW are non-scientists (in other words most of the people in the world) who are not trained to understand the issue at hand. Like a clerk espousing about the engineering issues of an airplane or skyscraper.
However, it does not matter that there were more CO2 (undeniable) in the atmosphere of the earth millions of years ago. The issue is that IF the ice caps of the world melts and sea levels rise, hundreds of millions of people will be left homeless and trillions of real estate and investments were lost. Consider Manhattan getting drowned in 4 feet of water. Everybody in Manhattan would be homeless and almost everybody working in Manhattan would suddenly be without a job. Whether it happens in 1 day or 30 years, the cost and implications are the same. You do not need to be a scientist to understand this.
Whether temperatures are rising due to human use of fossil fuels or not (scientific consensus is that it IS - simple math says so - CO2 is a greenhouse gas - humans produce about THIRTY times as much CO2 as is released through natural processes). Where people lose their senses is that this is not about EARTH SURVIVING. It WILL. We might not. Or at least in vastly smaller numbers due to a resource crunch. Think about all the wealth and economic potential getting lost if most of the big coastal cities in the world gets lost due to flooding.