Since 2008/2009, conservation agriculture (CA) cropland area has been expanding globally at an annual rate of more than 10 M ha per year. In 2015/2016, the total CA cropland area was 180.4 M ha, corresponding to 12.5% of global cropland area. In 2018/2019, the total cropland area was 205.4 M ha, corresponding to 14.7% of global cropland area. The spread of CA has been expanding in Asia, Africa, and Europe in recent years because farmers are becoming better organized in working together and networking. More attention and resources are being allocated by stakeholders towards supporting farmers to adopt CA and in generating new knowledge to improve their performance. Globally, expansion of CA remains largely farmer-driven and has become a multi-stakeholder movement comprising formal and informal CA networks at national and international levels involving individuals and institutions in the public, private, and civil sectors. Several lessons from the global spread of CA are elaborated responding to the questions:

(i) Why are the three interlinked CA principles universally applicable?
(ii) Why does CA work sustainably and optimally?
(iii) Why does CA deliver ecosystem services?
(iv) Why is CA a valid alternative agricultural paradigm for sustainable development?
(v) What are the sufficient conditions for scaling and mainstreaming CA?