Unintended consequences infest all decisions. If you think the earth's climate is going to get too hot you have three choices: 1) Start doing things to keep the environment cool; 2) Start doing things to let you survive in much hotter environments; 3) Just keep on keeping on.
What are the unintended consequences of each choice? Problems with many variables and with complex interactions are unlikely to be solved by a simple solution. Example: if you choose #1, you will need to at least severely decrease CO2 and NO2 production by decreasing industial production, by decreasing the number of people using energy that produces CO2 and NO2. What are the immediate 'unintended consequences'?
The human brain is torn between simple intuition and the more complex hard work of figuring out the unintended consequences of any policy. Who doesn't like thinking about trees and greenery and happy animals? Who doesn't want to see steps taken to protect those things, all else being equal? But all else is not equal. Civilization doesn't work when central planners treat each tree as if its value is infinite.
Politicians specialize in convincing you that, with their help, you can have your cake and eat it, too. The idea of a new "green economy" that is both clean and rich...
The likelihood of human actions significantly reducing the quantity of CO2 in the environment, sufficient to significantly reduce human-caused heating is... zero.
The likelihood of doing damage to something unintended or improperly understood while we're attempting artificially to cool the environment is ... very close to 1.
And most importantly: the NEED to do anything to affect the climate is... zero. There is no longer any excuse for touting the possibility that humans are going to cause a climate catastrophe; there is simply no evidence supporting that claim.