The possibility of moving a lot of heavy industry to space quite fascinates me! Looking at the raw numbers of how much heavy industry pollutes, really indicates the amount of positive impact moving it could have.
The percentage of global emissions heavy industry contributes is about 21 to 22 percent by what I found. A report linked by climate.nasa.gov states 21 percent in 2010. The report: https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_summary-for-policymakers.pdf
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