This sounds very problematic to me. Engineering is not meant for complex issues, it needs reductionism to complicated but highly predictable causal chains to be able to engineer it. Also wrt environment I don't see actual evidence of techno-optimism having had positive impact, let alone at geo-engineering scale. Environmental achievements wrt sulfur (acid rain), ozon (HFCs), living rivers (pesticides, discharges) etc. result from regulations limiting what engineers had previously introduced.