Dr. David Pierce, climatologist from the Climate Research Division of the Scripps Institution of Oceanography told the audience at the La Jolla Community Center on October 15, that when it comes to climate change, it’s best to “look at the phenomenon and examine the evidence,” before attributing the event to human or natural causes. For example, one of the wildfires in northern San Diego was caused by lightning strikes verses the local Eagle fire of 2011, which was caused by arson. So it is “natural and human factors together that are causing temperature increases in the earth.”
Pierce, the third featured speaker in the Center’s Distinguished Speaker Series, suggested that individuals pay attention to the overall trends and let the research speak for itself. He listed three main factors that affect the surface temperature of the planet (1) more sunlight (2) the reflecting energy of the sun (3) what gases are in the atmosphere. He pointed out that for more than 100 years, it has been known that greenhouse gases will warm the planet and observations show these gases are increasing in the atmosphere---all pointing to the positive connection between their increase and warming of the planet. But Pierce warned that one must clearly adhere to the evidence. Although reported to have a huge impact on rising temperatures, he said that “it’s not the sun that’s causing increased warming of the planet and if individuals think so, they haven’t looked at the evidence.”
To Pierce, this means examining all the causes of global warming—from the natural and human causes, to greenhouse gases, and solar and volcanic activity and all the evidence. Specifically, the evidence is in the form of many independent measurements pointing to the Earth’s warming including land and ocean temperatures, snowpack, early blooms, bird migration patterns, death of coral reefs, etc. In addition, he added that these trends should also include the warming of lands equally as well as the warming at high latitudes, annual precipitation cycles and the effect of sea levels rising.
Some questions from the audience included a query about the effect of reducing beef consumption reducing greenhouse gas levels. Pierce pointed to the positive correlation. He also suggested individuals continue to query elected officials about their efforts to address the problems of climate change in a state that is more liberal in its approach to the issue.