Will global warming have any real effect on me? Jonathan Overpeck from the University of Arizona addressed this question in his keynote speech, which concluded the Antarctic Peninsula Conference on April 5. The response was an overwhelming "yes," regardless of where you live.
Recent stories in the news have reported falling temperatures in Antarctica, but this can be attributed to year-to-year variability. Everywhere else on Earth shows temperatures steadily rising for the past century. According to the Intergovernmental Panel on Climate Change (IPCC), two-thirds of the warming observed in the past century is attributable to human actions.
Overpeck studies paleoclimate, or what the earth's climate was like before written records. "Paleoevidence suggests that climate change will be large, not small." He cited examples from paleohistory such as droughts up to ten times larger than the Dust Bowl. Overpeck continued, "Gradual climate forcing, which we are currently doing, has yielded surprisingly fast climate responses in the past. We still don't have the understanding that would allow us to predict these responses."
Global warming will have more effects than simply a rise in temperature, which is why it will affect everyone. Biodiversity will decrease on all continents due to heavily fragmented landscapes and reduced genetic flexibility. Places that will be hit the hardest are heavily populated areas, biodiversity hotspots, and coral reefs. Algae living on coral reefs (thereby providing essential nutrients to the coral) are highly temperature sensitive. Even slight warming can cause the death of these algae and their coral hosts. Recent El Niño events have resulted in coral deaths, and this could be more widespread with global warming.
All these events combined cause Overpeck to believe the more dire predictions he sees in models and hears in the news. The IPCC predicts a rise in temperature of 1.4 to 5.8°C by the year 2100. Jonathan Overpeck has seen records of climate variability in the past and thinks that the higher end of this range may be correct.
