Reducing atmospheric CO₂ using biomass energy and photobiology

Biological systems are among the most promising, environmentally sustainable alternatives for reducing atmospheric CO₂ levels. Biomass can act as a reservoir of carbon, or as a direct substitute for fossil fuels with no net contribution to atmospheric CO₂ if produced and used sustainably. We examine the role of biomass in mitigating global warming and contributing to the development of future energy strategies. We conclude that the use of biomass for fossil fuel substitution would be far more effective in reducing atmospheric CO₂ than to simply sequester CO₂ in forests in most circumstances. Furthermore, since bioenergy could be less costly than coal and petroleum, this strategy has an economic advantage over many of the carbon mitigation options. Photobiology and photochemistry are possible future routes for CO₂ reduction. The use of microalgae in photobioreactors is feasible for CO₂ removal as has been demonstrated in a number of laboratories. Energy balances with such systems need to be optimised since parameters such as light (actual and artificial) and waste heat play crucial roles.