Nutrient Cycles and Climate Change
Researchers recently reported that extreme weather patterns have become more likely due to human-induced global warming. They determined that human contribution to global climate change had made the 2011 Texas heat wave approximately 20 times more likely. Similarly, the abnormally high temperatures in Britain last fall were 62 times more likely because of global warming. However, the scientists’ research methods have received much criticism from the community. Although investigations of human impact on climate change usually take several years, these researchers studied six events from 2011 and published their findings in only six months. Some of the researchers warned that because of the compressed time period of the study, the findings are only tentative. The new research consistently suggested that the weather extremes witnessed in recent years are the result of global climate change. Specifically, heat waves have become more severe with global warming and the water cycle has “intensified.” An intensification of the water cycle would mean more droughts and heavy rains. The findings on extreme weather were announced along with a report on the overall condition of global climate. Specifically, this report reinforced previous findings that the Arctic was warming more rapidly than other parts of the world. Similarly, it stated that Arctic sea ice is at the second-lowest level on record. This broader report also found that heavy rains in 2010 actually caused sea levels to fall. By 2011 this rainwater had found its way to the ocean, contributing to rising sea levels. Although both reports suggest that global warming has made extreme weather patterns more likely, other factors must be taken into account. For instance, changes in “human exposure and vulnerability” to extreme weather must also be considered. For instance, the researchers concluded that last year’s devastating floods in Thailand were not the result of global climate change. Rather, the researchers asserted that rapid industrial development in Thailand played a much larger role than global warming alone. Indeed, Dutch and British researchers determined that the amount of rainfall was not out of the ordinary. Instead, the construction of factories on the floodplains of large rivers increased the likelihood of disaster and human casualties. Likewise, researchers in Oregon and Britain determined that the 2011 Texas heat wave could have been caused by natural variations in climate along with global warming. Significantly, these researchers attributed the Texas heat wave and other extreme weather events in 2011 to La Niña. La Niña has effects worldwide, and makes droughts in the Southwest of the US more likely. Even with the effects of La Nina accounted for, the researchers acknowledged that rising temperatures worldwide made the Texas heat wave 20 times more likely. Despite these findings, meteorologists like Martin P. Hoerling have remained skeptical of the new research. Hoerling is conducting his own investigation of the Texas heat wave, but determined that the lack of rainfall was not linked to global warming.