气候

目标考虑到化石燃料燃烧和水泥生产趋势、全球变化惯性以及发展中国家未来的能源需求。目前全球二氧化碳排放量约为10千亿吨/年。建议到2023年达到12亿吨碳当量/年的上限。建议制定一个切实可行的减排计划——到2030年恢复到10.5 GtC/年，到2050年减少到6 GtC/年，2062年减少到3 GtC/年，2078年减少到1 GtC/年。我们的预测模型假设发展中国家在2062年之前将适度地燃烧化石燃料，而今天的工业国家则通过高影响的大气碳捕获来补偿，再加上它们自己的抵消减排——足以在2023年之前限制全球排放，并在2062年之前实现上述目标减排。发展中国家将在2063年开始或加速减排。我们的预测模型预测了排放上限和减排对大气二氧化碳累积混合比(ppm)的影响。仅靠减排已经不太可能阻止二氧化碳达到450ppm的临界点。需要采取更严厉的紧急干预措施，以防止越过临界点，并防止未来的灾难性后果，包括≥2°C的升温伴随特大干旱、超级风暴、部分极地冰崩塌和突然的灾难性海平面上升。提出了一种涉及大规模放大的海洋大气二氧化碳安全捕获的新方法。 This paper establishes open-ocean amplified capture targets and forecasts the beneficial impacts of meeting them. Recommended high impact targets for mid-ocean capture and sequestration of atmospheric CO2 include contingency for delays and energy to drive multi-stage (land/sea) amplified capture plus extra contingency to offset feedbacks, outgassing, and permafrost thaw-release, which the model didn’t anticipate. CRT recommends starting multi-stage short-cycle ocean-amplified carbon capture (OACC) in 2019 and ramping it up to net 10 GtC/yr average CO2 capture by 2025 across vast mid-latitude, mid-ocean expanses—far out at sea and well away from coastal waters—plus simultaneously compounding benefits of the 12 GtC/yr 2023 emissions cap and above-targeted post-2023 emissions reductions, culminating in 92 percent reduction by 2078. With the sum of OACC plus natural sinks matching capped emissions by 2023 and substantially exceeding reduced post-2023 emissions, accumulated atmospheric CO2 may be capped at ≤ 425 ppm by 2023 and reduced to 350 ppm by 2050, with an option to restore 280 ppm by 2075 and reduce twenty-first century warming to 0°C. High-impact ocean-amplified carbon capture (OACC) at the rate of 10 GtC/yr could enable DC emissions leniency and still turn 280 ppm atmospheric CO2, ∆T = 0°C, and ocean pH 8.2 into viable twenty-first century targets that can be met approximately 250 years earlier than with emissions reduction alone—if tropospheric aerosol pollution is concurrently reduced.