Frequently Asked Questions on 1.5°C and Geoengineering Published: 15 March 2019 What's the difference between 1.5°C and 2°C? What are "negative emissions"? What's the problem with geoengineering? Why and how is the Heinrich Böll Foundation working on the topic of geoengineering and the 1.5°C limit? Answers to the most frequently asked questions about the 1,5°C target and the topic of geoengineering.