There is growing recognition that meeting the climate objectives of the Paris Agreement will require the world to achieve net-zero carbon dioxide emissions around or before mid-century1–4. Natural climate solutions (NCS), which aim to preserve and enhance carbon storage in terrestrial or aquatic ecosystems5,6, are increasingly being evoked as a potential contributor to net-zero emissions targets7,8. However, there is a risk that any carbon that we succeed in storing in land-based systems could be subsequently lost back to the atmosphere as a result of either climate-related or human-caused disturbances such as wildfire or deforestation9–12. Here, we show that temporary NCS-based carbon sequestration has the potential to decrease the peak temperature increase, but only if implemented alongside an ambitious mitigation scenario where fossil fuel CO2 emissions were decreased to net-zero during the time that NCS-sequestered carbon remained stored. We also demonstrate the importance of non-CO2 climate effects of NCS implementation, which have the potential to counter a substantial portion of the climate effect of carbon sequestration. Our results suggest that there is some climate benefit associated with temporary NCS, but only if implemented as a complement (and not an alternative) to ambitious fossil fuel CO2 emissions reductions.