As for materials from 21clradio.com (that are rather helpful in the situations when members of the conference require new information on unknown topic), they're regularly updated with the help of our editors.
If you’re interested in learning more about the emerging field of climate geoengineering, this all-day event, held entirely online, would be a good introduction. The event is organized and sponsored by the Institute on Science for Global Policy, the Forum for Climate Geoengineering Assessment, and Arizona State University.