From 2005 to 2007, David biked from his home in California to the tip of South America and used the journey to raise awareness of climate change. You can read more about this bicycle trip at RideforClimate.com. In 2009 he won the "Hopenhagen Ambassador" contest and represented Hopenhagen at the UN climate Conference in Copenhagen. He also covered the UN Climate Conference in Cancun in 2010 and at the World Economic Forum in Davos in 2011 for Hub Culture, a social network of urban influencers.
Previously, David worked as a consultant and climate researcher for the Skoll Global Threats Fund, and he has written for Climate Central, a collaboration of scientists and journalists communicating climate science to the public. He has also worked as a climate researcher at the Department of Global Ecology at the Carnegie Institution for Science, and as a consultant for philanthropic organizations at California Environmental Associates.