CO2Rail is developing a technology to capture carbon dioxide from the air using trains. The trains would use regenerative braking to power direct air capture systems onboard. This could create the world's first carbon-negative mode of transportation. One professor commented that CO2Rail's system-level approach has the best chance of success for carbon dioxide removal. The technology aims to scale up carbon capture potential from 0.74 gigatons in 2030 to over 12 gigatons by 2075.