The spread of coronavirus has caused the cancellation of multi-thousand-person conferences. The world of online, many-to-many communication media — audio and video, forums, blogs, mail lists, collaborative documents, slideshows, whiteboards — is like a supersaturated solution and the pandemic is the seed crystal for a state change: Even without a pandemic, the carbon footprint of transporting thousands of people thousands of miles for a two or three day meeting demands action. The time has come to at least severely reduce the number of large international face to face conferences. The good news is that the available tools are robust and either free or inexpensive. However, a successful online conference doesn’t just happen — everybody knows how to partake in keynotes, workshops, hallway conversations at face to face gatherings. The skills of presenting and participating in an online version are nowhere near as widely spread. Conveners need to document, frame, and support training into how to use the new medium, as well as plan and present the keynotes and workshops at the heart of the conference. Skilled facilitators of online discourse are a must. Fortunately, there are plenty of people with the right skills.