Because once you start talking about economics and fiscal issues you rapidly lose control of the political discussion. Suddenly, the issue isn't 'we must do x' it is 'x costs y and has z payoff.'
This is a major political problem because the way public understands most issues is that there isn't a tradeoff between costs and benefits like this. When there is it's usually hidden behind a myth like 'the space program produces lots of commerical knowledge' or 'military spending produced the internet.' Of course, neither of these is true in any real sense. It doesn't mean that the space program or military spending don't have benefits in and of themselves but claiming that they didn't cost anything because they produced ancillary benefits that just so happened to cover their investment is magical thinking.
You have the same problem with discussions on green energy today. Saying we have to invest in green energy not because of climate change but because "that is where all the jobs will be" and "renewable energy pays for itself because it is cheaper" are basically the same kind of mythmaking to rationalize away costs.
From a political perspective, this makes a lot of sense. If you want a discussion about actual costs and expected payoffs you can't claim that climate change legislation has no downsides; which, while true, is incredibly problematic to assert.
What you want to do is have the costs managed internally by the political coalition so you can handwave away hard discussions about fiscal issues. Of course, it always turns out that the subsidies required are either always politically acceptable or do much less than what population expects.
This is a major political problem because the way public understands most issues is that there isn't a tradeoff between costs and benefits like this. When there is it's usually hidden behind a myth like 'the space program produces lots of commerical knowledge' or 'military spending produced the internet.' Of course, neither of these is true in any real sense. It doesn't mean that the space program or military spending don't have benefits in and of themselves but claiming that they didn't cost anything because they produced ancillary benefits that just so happened to cover their investment is magical thinking.
You have the same problem with discussions on green energy today. Saying we have to invest in green energy not because of climate change but because "that is where all the jobs will be" and "renewable energy pays for itself because it is cheaper" are basically the same kind of mythmaking to rationalize away costs.
From a political perspective, this makes a lot of sense. If you want a discussion about actual costs and expected payoffs you can't claim that climate change legislation has no downsides; which, while true, is incredibly problematic to assert.
What you want to do is have the costs managed internally by the political coalition so you can handwave away hard discussions about fiscal issues. Of course, it always turns out that the subsidies required are either always politically acceptable or do much less than what population expects.