Lexy Garcia / Reporter An increasingly politicized issue, climate change and the rate of global warming, is thought to be caused by human activity, according to many scientists. The percentage of Americans who view climate change as a “serious threat” has been increasing since 1998, according to a recent Gallup poll. While 97 percent of researchers agree that humans are the cause of global warming, Vernon Kramer, an assistant professor of geology at Del Mar College, said there is nothing humans can do or stop doing to affect the environment. “Locally we can affect our climate, we can recycle and conserve,…