Negative Emissions Technologies (NETs) 1 have the potential to remove carbon dioxide (CO2) from the atmosphere and this could reduce the impacts of ocean acidification and anthropogenic climate change. NETs are a family of technologies that encompass diverse options, including: Afforestation, Agricultural Soil Carbon Sequestration, Biochar, Bioenergy with Carbon Capture and Storage (BECCS), Direct Air Capture (DAC), Ocean Liming, Enhanced Weathering, and Ocean Fertilisation. NETs may help to extend carbon budgets and therefore provide more time to reduce emissions. Carbon budgets represent our best estimates of the amount of CO2 that may be released into the atmosphere before it becomes unlikely that the 2°C target can be avoided. Based on the latest IPCC work2 the current carbon budgets are 900, 1050 and 1,200 GtCO2 under 66%, 50% and 33% probabilities, respectively. In 2010, gross annual Greenhouse Gas (GHG) emissions totalled ~50 GtCO2-equivalent. Ocean and land sinks absorb just over 50% of the emissions resulting in net atmospheric emissions increasing by around 22 GtCO2 pa and therefore an average ~3 ppm increase of atmospheric CO2 concentration per year, although the fraction absorbed by these sinks is falling.3 To see whether carbon budgets can be extended and if so, for how long, we use the methodology used by the Carbon Tracker Initiative when it assessed the role of Carbon Capture and Storage (CCS) technology development and deployment on carbon budgets. It used the IEA CCS Roadmap4 to quantify the ‘extra space’ that would be created in carbon budgets and found that a total of 125 GtCO2 could be sequestered by 2050; this is the equivalent of 2.5 years of present gross annual emissions.