Recently, scientists have been discussing global warming and its negative effects on the world. Climate change, one of the direct effects of global warming, accounts for the recent heat waves and extreme summers. Though scientists reiterates the effects global warming is having on the earth, more recently there has been a growing concern for what global warning means for one's health.

In a study conducted by James Hansen and colleagues from the NASA Goddard Institute for Space Studies in New York City, they examined the role of global warming in recent heat waves such as the ones in Texas, Oklahoma and Moscow. Hansen's study revealed that extremely hot summers—those with temperatures greater than the average temperature—occurred more frequently in the past several years than ever before.

With more air pollutants present as an effect of global warming, scientists are concerned about the reduced air quality that can increase the risk of respiratory illnesses. According to the United States Environmental Protection Agency (EPA), ground-level ozone can cause fatal damage to one's lung tissue reducing lung function and inflaming airways. An increase in ozone exposure also leaves individuals vulnerable to develop acute or severe respiratory illnesses that include allergies, asthma, bronchitis and pneumonia.

Of the many cardiovascular and respiratory illnesses associated with climate change and global warming heat stroke is the most severe of them all. According to the Centers of Disease Control and Prevention, in a study conducted between 1999-2203, there were a total of 3,442 deaths resulting from extreme summers. Those heated-related illnesses included, heat cramps, heat exhaustion and hyperthermia.

These extreme summers are greatly affecting the health of individuals worldwide. Just last month alone, in Japan, during the week of July 23-29, more than 8,000 people were hospitalized due to a heat stroke and of those patients, 16 people died. Japan Meteorological Agency forecast higher than average temperatures for August and September.

In August 2011, the New York Post reported seven heat-related deaths among the elderly.

In states such as Texas, where temperatures can hit above an overwhelming 100 degree Fahrenheit, the concerns of heat-related deaths among Texas Department of Criminal Justice are on the rise. The New York Times reported last month a total of10 inmates died in 26-day period in 2011.

Not only can climate change have a direct effect on one's health, but also an indirect effect as well. Climate changes increases the risk for food-borne diseases such as salmonella, air-borne diseases such as West Nile Virus and water-borne illnesses such as Giardia that can be found in drinking water. There have already been reported 144 serious cases of West Nile Virus, including four deaths.

As global warming continue to affect the air quality and trigger climate change the EPA is working alongside the CDC and Federal Emergency Management Agency (FEMA) to develop healthy cities that will be prepared for climate change.

To learn more about the direct or indirect effect of climate change visit the U.S. Environmental Protection Agency.

The study was published in the Proceedings of the National Academy of Sciences.