Global Warming

The concept of greenhouse gasses leading to man-made global warming has existed in the consciousness of some for many years, and the debate grew in intensity and evidence in the 1990s. In the United States, public awareness of global warming reached its peak in 2006 with the release of the controversial documentary An Inconvenient Truth, which chronicles former Vice President Al Gore's crusade to educate the public about the dangers and man-made nature of the climate change we are experiencing.

While the initial debate focused on whether or not the world was experiencing a significant warming, today it has more to do with whether or not it is attributable to human interference. Estimates put the rise in the global surface temperature at 0.6 degrees Celsius, plus or minus 0.2 degrees. While this does not seem like much, the following infographic depicts how much damage even a small amount of warming can cause:

While most people will at this point agree that the earth is in fact experiencing a significant period of warming, many attribute this warming to the natural cycle of warming and cooler that the earth experiences over time. The majority of the scientific community, however, believes that this change can be attributed to the effect of greenhouse gasses in the atmosphere, which hold heat in. These experts make their case by graphing the increase in carbon dioxide (a greenhouse gas) emissions against warming trends. The result looks something like this:

While the media presents the issue as an extremely contentious one, the scientific community, with a few notable exceptions (hi Dr. Rood!), seem to believe that at least some of the warming we have experienced can be attributed to human factors. The following graphic displays the results of several different studies about opinions of global warming in the scientific community:

Ultimately, it is difficult to know exactly how much of the warming we are experiencing is attributable to human factors, and how much is part of a natural temperature cycle. However, we can all agree that whether or not humans contributed to the causes of warming, humans will suffer the consequences. It is important that rather than investing our time in ad hominem attacks against those who believe differently than us, we focus on preparing our world, especially in the underdeveloped regions that are likely to experience the brunt of climate change's most negative effects, for the changes that are occurring.

Finally, because this is a contentious issue which often makes people uncomfortable or angry, I leave you on a lighter note. Here is the definitive proof of global warming!

Banqiao Dam Disaster

On August 8, 1975 the Banqiao Reservoir Dam in Zhumadian Prefecture, Henan Province, China, suffered a catastrophic failure, leading directly to the deaths of 26,000 people and affecting more than 11 million people in total. Although some may consider a dam failure to be an engineering failure or man-made disaster, the Banqiao Dam incident is officially considered a natural disaster because of the extreme rainfall and flooding that precipitated the disaster. A typhoon caused more than a whole year's worth of rain to fall in 24 hours. While the dam was engineered to withstand above average rainfall, it did not have the capacity to handle this extreme flooding, which climate experts have labeled a "once-in-a-thousand-years" event. The water peaked at 117.94 meters above sea level, which was 0.3 meters higher than the wave protection wall. The resulting dam breakage released over 701 million cubic meters of water in six hours.

Several measures were unsuccessfully taken to avoid the breakage of the dam in the first place. Workers at Banqiao requested permission to open the dam and thus avoid catastrophic failure, however, the response authorizing them to do so, sent by telegram, failed to reach its recipients. Communications orders also failed in the transmission of evacuation orders, and seven county seats were flooded before they had been fully evacuated, leading to a high death toll. At the time, there was no cohesive early warning system in China for disasters of this kind, which could have prevented much of the damage.

The first response to the disaster was the intentional destruction of several other dams in the area in order to avoid a chain reaction of similar dam breaks. Next, the People's Liberation Army was deployed to for initial disaster aid. Their primary job was to rescue victims who had survived the initial massive release of water and were now trapped by debris, stranded in a dangerous environment, or separated from their homes and families. Next, the government began airdropping supplies of food and medicine to the worst-affected areas. The long-term consequences of this disaster and the reactions to these consequences were largely concerned with famine and epidemics due to destroyed or damaged agricultural land and the spread of water-borne illnesses. All told, it is difficult to say exactly what the death toll, environmental health impact, and economic damage caused by this disaster was. It is also difficult to say how an early warning system and more advanced and organized approach to disaster relief could have mitigated these impacts. However, this scenario does illustrate the dangers that natural disasters can pose to environmental health, especially when disaster preparedness is not functioning at the highest possible level.