Global warming: one of the hottest and most politically challenging issues of the 21st century, and for good reason. The potential damage is enormous: melting ice sheets (causing sea levels to rise and available fresh water to dwindle), more common droughts and floods, more severe natural disasters, and a complete overhaul of our ecosystem (nationalgeographic. com). Combining these factors and adding them in a few hundred years, we could have a complicated situation. We know what could happen if the trend of rising universal temperatures continues, but no one seems to pinpoint the exact reasons why this is happening. Is it a natural phenomenon? Do humans cause it? Or as Charlie Perry, a scientist at the United States Geological Survey, suggests: variation in the number of sunspots causes climate change and rejects the widely accepted theory that it is caused by high levels of carbon dioxide (Lawrence Journal World 3). For background, a sunspot is a region of the solar photosphere that is cooler and darker than the surrounding material. Sunspots often appear in pairs or groups with specific magnetic polarities that indicate electromagnetic origins. It highlights the fact that every eleven years the sun goes through cycles of high and low solar activity; right now we are in a period of minimal solar activity. In 2009, in fact, the sun was on track to set the record for the fewest sunspots in a three-year period (1). However, there is an inherent problem with his argument: he provides no scientific data on how solar activity affects the temperature of our climate. The only evidence he could provide is that one of the cycles occurred in 1913, which he says is "a time when old-timers talk about it being really cold" (2). Submitted readers leave... half of the paper... then there is a world organization that dedicates years of research before publishing reports on global warming. Works Cited "AR4 SYR Summary Report". IPCC – Intergovernmental Panel on Climate Change. United Nations, 2007. Web. March 31, 2011. "Information about the effects of global warming, facts about the effects of global warming, effects of climate change - National Geographic." Environmental information, environmental science, global warming, natural disasters, ecosystems, ecological living - National Geographic. National geographic. Network. 31 March 2011. "Definition: sunspots". Extraordinary space. Space Telescope Science Institute. Network. March 31. 2011. .