Negative Emission Technologies and Land Use

by John Katzenberger, Aspen Global Change Institute

December 2019 Quarterly Research Review

Given the aspirations of the Paris Accord, the challenge facing humanity can be expressed in simple terms: halve annual CO2 emissions by 2030, halve them again by 2040, and again by 2050. The difficulty of the task goes up the longer peak emissions are delayed, as does the ultimate amount of negative emissions needed by 2100. Negative Emissions Technologies (NET) are a suite of technologies that can draw down CO2 from the atmosphere and by use or storage keep it from reentering the air. This simplistic prescription of halving annual emissions pencils out to reducing the 40 billion tons of CO2 (GtCO2) emitted today in each decade: first to 20, then to 10, and finally to 5 GtCO2. The final 5 GtCO2 offset by reducing land use emissions to zero and ramping up CO2 removal to 5 GtCO2 – all happening in about 30 years.