From wildfires to sea levels to hurricanes to shrinking ice caps to droughts to floods, the impacts of climate change are evident almost anywhere you care to look. Few remain who deny that the climate is different than it was, but there are some who continue to resist the notion that humans are responsible for, or are even capable of, influencing the global climate in such a dramatic fashion. It turns out, though, that human influence on the climate may be nothing new — in fact, it may be more than 5,000 years old. University of Wisconsin Climatologist Feng He authored a recent study that suggests that the dawn of agriculture may have had as profound an effect on the climate as has the industrial revolution. He joined the Monday Buzz on April 21.