Space-based active sensing of ${\mathrm{CO}}_2$ concentration is a very promising technique for the derivation of ${\mathrm{CO}}_2$ surface fluxes. There is a need for accurate spectroscopic parameters to enable accurate space-based measurements to address global climatic issues. New spectroscopic measurements using laser diode absorption spectroscopy are presented for the preselected R30 ${\mathrm{CO}}_2$ absorption line ( $({20}^{0}1{)}_{III}\leftarrow (000)$ band) and four others. The line strength, air-broadening halfwidth, and its temperature dependence have been investigated. The results exhibit significant improvement for the R30 ${\mathrm{CO}}_2$ absorption line: 0.4% on the line strength, 0.15% on the air-broadening coefficient, and 0.45% on its temperature dependence. Analysis of potential biases of space-based DIAL ${\mathrm{CO}}_2$ mixing ratio measurements associated to spectroscopic parameter uncertainties are presented.