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Terraforming Mars: Mass, Forcing, and Industrial Throughput Constraints

Slava G. Turyshev

Abstract

Terraforming Mars can be evaluated with a small set of system-level feasibility constraints linking (i) target pressures and compositions to required atmospheric inventories, (ii) target surface temperatures to required radiative control authority, (iii) inventories and radiative agents to sustained industrial throughput and power over a build time, and (iv) persistence against collapse, escape, and geochemical sinks. We use transparent order-of-magnitude scalings to map proposed levers (endogenous CO$_2$ release, synthetic super-greenhouse gases, CO$_2$-H$_2$ CIA, engineered aerosols/nanoparticles, orbital mirrors/albedo modification, and regional solid-state greenhouse ``paraterraforming'') onto common metrics $\{M,\ τ_{\rm IR}/ΔF_{\rm TOA} \dot M,\ P\}$. We find: (1) human-relevant pressures imply exaton-class inventories, $M_{\rm atm}\simeq 4πR_{\rm Mars}^2 P_s/g_{\rm Mars}\sim 10^{17}$-$10^{18}$ kg; (2) accessible CO$_2$ plausibly provides $\lesssim 20$ mbar, yielding $\lesssim 10$ K warming under present insolation; (3) achieving $T_s$ ~ 250-273 K at current insolation requires an effective IR opacity target $τ_{\rm IR,eff}\sim 2$--4 (uncertain at the ~30-50% level but not altering mass-scale conclusions); (4) breathable endpoints are dominated by O$_2$ and buffer-gas mass and by a minimum oxygenation work $\gtrsim 10^{25}$ J, implying $\dot M\sim 10^{7}$-$10^{8}$ kg\,s$^{-1}$ and multi-$10^2$ TW to PW-class average power for century-to-millennial build times. We conclude that regional habitability gains via paraterraforming are plausible on near-term industrial scales, whereas global transformation of Mars requires multi-century planetary industry and becomes credible only under conditions of (a) massive exogenous volatile supply or much larger discovered inventories, and (b) sustained high-authority climate control and retention against sinks and loss.

Terraforming Mars: Mass, Forcing, and Industrial Throughput Constraints

Abstract

Terraforming Mars can be evaluated with a small set of system-level feasibility constraints linking (i) target pressures and compositions to required atmospheric inventories, (ii) target surface temperatures to required radiative control authority, (iii) inventories and radiative agents to sustained industrial throughput and power over a build time, and (iv) persistence against collapse, escape, and geochemical sinks. We use transparent order-of-magnitude scalings to map proposed levers (endogenous CO release, synthetic super-greenhouse gases, CO-H CIA, engineered aerosols/nanoparticles, orbital mirrors/albedo modification, and regional solid-state greenhouse ``paraterraforming'') onto common metrics . We find: (1) human-relevant pressures imply exaton-class inventories, - kg; (2) accessible CO plausibly provides mbar, yielding K warming under present insolation; (3) achieving ~ 250-273 K at current insolation requires an effective IR opacity target --4 (uncertain at the ~30-50% level but not altering mass-scale conclusions); (4) breathable endpoints are dominated by O and buffer-gas mass and by a minimum oxygenation work J, implying - kg\,s and multi- TW to PW-class average power for century-to-millennial build times. We conclude that regional habitability gains via paraterraforming are plausible on near-term industrial scales, whereas global transformation of Mars requires multi-century planetary industry and becomes credible only under conditions of (a) massive exogenous volatile supply or much larger discovered inventories, and (b) sustained high-authority climate control and retention against sinks and loss.
Paper Structure (70 sections, 59 equations, 2 figures, 10 tables)

This paper contains 70 sections, 59 equations, 2 figures, 10 tables.

Table of Contents

  1. Introduction
  2. What "terraforming Mars" means in quantitative terms
  3. End states and success metrics
  4. Key results at a glance
  5. Atmospheric mass bookkeeping: pressure targets imply exaton-scale gases
  6. Pressure--mass relation
  7. Composition matters: CO$_2$ is a poor buffer gas
  8. CO$_2$ toxicity constraint.
  9. Available buffer gas on Mars.
  10. Column mass as a proxy for radiation and aerodynamic shielding
  11. Buffer gas mass scales and import energetics
  12. External sourcing.
  13. NH$_3$ as an N-carrier.
  14. How much fixed nitrogen would Mars need to supply a buffer gas?
  15. Thermal requirements: radiative forcing and the 60 K problem
  16. ...and 55 more sections

Figures (2)

  • Figure 1: Atmospheric mass required for a given mean surface pressure on Mars from Eq. (\ref{['eq:mass_pressure']}). A 1bar atmosphere corresponds to $M_{\mathrm{atm}} \approx 3.89\times 10^{18}\,\mathrm{kg}$.
  • Figure 2: Order-of-magnitude mirror area required to supply a global mean additional absorbed flux $\Delta F_{\mathrm{TOA}}$ at Mars orbit, using Eq. (\ref{['eq:mirror_area']}) with $\eta_m=0.7$ and $S_{\mathrm{Mars}}=589W\,m^{-2}$Alexander2001MarsEnv.