What do you think would ruin the global economy specifically?
Spending money we don't have and losing much of our energy infrastructure. Ref: the recent regulations impacting the US coal industry. This could be mitigated by building nuclear power plants again, but the irrational phobias out there are preventing that in the US.
What makes you think several trillion dollars need to be spent?
There are many such estimates on the web. Here's the first one I found:
Capital Cost of Germany's ENERGIEWENDE
- The capital cost estimate for Germany to implement its ENERGIEWENDE would be about $4.5 trillion by 2050, according to a cost estimate by Siemens.
- The US capital cost would be about $18.7 trillion by 2050, if the US were to follow Germany’s course.
- The world’s capital cost would be about 3-4 times the US cost, if the entire world were to follow Germany’s course.
Global Warming Targets and Capital Costs of Germany's 'Energiewende' | Energy Central
What makes you think we don't have several trillion dollars?
Latest reports put our current debt at over 16 trillion dollars, and unfunded mandates could run as high as 100 trillion dollars.
Edited by Coyote, : typo
™ Version 4.2
(1)
