[ABSTRACT] Atmospheric carbon dioxide (CO2) concentrations have increased by about 50% compared to before industrialization, causing serious effects such as global warming and climate change. In Japan, the target is to reduce CO2 emissions by 46% by 2030 and to achieve “carbon neutrality” by 2050. Not only reducing CO2 emissions but also expanding CO2 sequestration are important to fulfil carbon neutrality. Soil is a huge carbon storage and stores nearly three times as much carbon as terrestrial vegetation and more than twice as much as the atmosphere. Increasing the amount of carbon stored, “carbon sequestration” is a key to mitigate global warming and climate change. In this paper, we will introduce in detail the protection of soil surfaces and incorporation of carbon-containing substances into soils as technologies for carbon sequestration. In addition, focusing on urban green spaces, green infrastructure, management practices of green spaces may also be able to contribute to mitigation of global warming and climate change. As a practical research project, “4 permille initiative @ Matsudo” will be suggested.