Last Thursday, October 15, was an exciting day for bloggers. It was the Blog Action Day, an annual event that bloggers around the world post about the same issue on the same day on their own blogs, with the aim of sparking discussion around an issue of global importance. This year, the topic was climate change. I represented JPL to write a blog about the roles of clouds play in climate change and how NASA JPL contributes to the studies of clouds and climate change (see http://blogs.jpl.nasa.gov). Although called upon at the last minute, I was happy to take on this task because I was pleased that climate change is recognized as an urgent problem that the world faces. I learned that there were 13,502 blogs from 155 countries on the Blog Action Day, reaching out more than 18 million readers. United Kingdom Prime Minister Gordon Brown made the first blog entry at the stroke of midnight on October 15 (12:01am!). His blog called all world leaders to join him to “forge a critical new deal on tackling climate change” at the upcoming international climate negotiations in Copenhagen this December. White House also posted a blog that emphasized United States’ commitment to clean energy economy. More than 50 world’s leading nonprofit organizations participated, covering many aspects of how climate change impacts our lives. As an atmospheric scientist, I feel pressed to work hard to improve our understanding of the climate systems and improve our predictions of climate change. As a citizen of the Earth, I feel my share of responsibility to reduce carbon footprint and preserve the livability of our home planet.