<p>Doug Osugi can't say exactly when he began believing in global warming. The realization that Earth's temperature truly is rising dawned gradually.</p>
<p>"It is not something that suddenly, the next day, you realize that it's true," said Osugi, a California water resources planner. "I think it's something that you're slowly being convinced that, yes, it's there, as more and more information comes out.</p>
