Any effective approach to atmospheric CO2 reduction on a timescale that matters will require extremely large quantities clean energy, far beyond current generation capacity. This will be the biggest bottleneck so start there.

Given that this is known required input, we can start by expediting the building this energy infrastructure with all due haste. This would require ignoring various activists with a litany of reasons for why deploying solar/wind/nuclear/geothermal at scale is stupid/immoral/unethical.