Though highly motivated to slow the climate crisis, governments may struggle to impose costly polices on entrenched interest groups, resulting in a greater need for negative emissions. Here, we model wartime-like crash deployment of direct air capture (DAC) as a policy response to the climate crisis, calculating funding, net CO₂ removal, and climate impacts. An emergency DAC program, with investment of 1.2–1.9% of global GDP annually, removes 2.2–2.3 GtCO₂ yr^–1 in 2050, 13–20 GtCO₂ yr^–1 in 2075, and 570–840 GtCO₂ cumulatively over 2025–2100. Compared to a future in which policy efforts to control emissions follow current trends (SSP2-4.5), DAC substantially hastens the onset of net-zero CO₂ emissions (to 2085–2095) and peak warming (to 2090–2095); yet warming still reaches 2.4–2.5 °C in 2100. Such massive CO₂ removals hinge on near-term investment to boost the future capacity for upscaling. DAC is most cost-effective when using electricity sources already available today: hydropower and natural gas with renewables; fully renewable systems are more expensive because their low load factors do not allow efficient amortization of capital-intensive DAC plants.

尽管积极地减缓了气候危机的动力，但各国政府仍可能难以对根深蒂固的利益集团强加昂贵的政策，导致对负排放的更大需求。在这里，我们将类似于战时的直接空袭（DAC）的崩溃部署建模为对气候危机的政策响应，计算资金，净CO ₂去除量和气候影响。一项紧急DAC项目，每年投资占全球GDP的1.2–1.9％，到2050年消除2.2–2.3 GtCO ₂年^–1，到2075年消除13–20 GtCO ₂年^–1，以及570–840 GtCO ₂累计超过2025年至2100年。与控制排放的政策努力遵循当前趋势（SSP2-4.5）的未来相比，DAC大大加快了净零CO ₂排放（至2085-2095）和峰值变暖（至2090-2095）的开始；然而，到2100年，变暖仍达到2.4–2.5°C。如此大量的CO ₂去除取决于近期投资，以提高未来的升级能力。使用当今已经可用的电源时，DAC最具成本效益：水力发电和天然气以及可再生能源；完全可再生系统的价格较高，因为它们的低负载系数无法有效地摊销资本密集型DAC工厂。