The terraforming of Venus

Methods are considered for the 'terraforming' modification of Venusian environmental conditions. It is noted that Venus cannot be terraformed by microbiological means alone, and that the massive importation of such materials as H2 from various regions of the solar system will have to be instituted; recent impact erosion research on atmospheres appears to preclude this as an option. More fundamentally, a decrease in the axial rotation period of Venus will be mandatory. Taking all factors into account, a project duration of 16,500 years, begining in 2500 AD, is envisioned. Human colonization could not begin before 19,000 AD.