Pollution problems

The average adult breathes 3000 gallons of air each day. Unfortunately, the air we take in is not limited to the gas molecules of nitrogen, oxygen, and argon that make up all but 0.04% of Earth’s atmosphere. Thanks to the burning of fossil fuels, additions in the form of carbon dioxide molecules, ozone, aerosols, and particles—also known as particle pollutants—have entered the atmosphere.

Particle pollutants are miniscule, often between 2.5 and 10 μm; they are known to cause an array of significant health problems, including irregular heartbeats, nonfatal heart attacks, and irritation of the airways. Even the healthiest people can be affected by particle pollutants, which can accumulate in the lungs and decrease lung function.

Many countries around the world, including the US, have developed a series of laws and practices to mitigate the increasing number of particle pollutants and their corresponding negative health problems. Some countries, however, are struggling to keep up with the sheer volume of particle pollutants that have been released into the atmosphere and will be facing the consequences for years to come.

February 2014 ended with record levels of pollution in cities across China. While many people in the northern hemisphere viewed the end of February as the end of a long, cold winter, the citizens of China were wearing face masks to protect themselves from what some Chinese scientists have compared to a nuclear winter. Particle pollution levels in Beijing at the end of February were recorded at an astonishing 505 mg/m³.

To put that value in perspective, the World Health Organization considers a safe level to be 25 mg/m³. Pollution values higher than the WHO threshold have dire effects on more than human health. Pollutive smog severely slows—and can even halt—the photosynthesis of crops, leading to food shortages and economic slowdowns. Reports from those facing the effects of excessive pollution suggest that the conditions inside Beijing have rendered the city almost uninhabitable.

Beijing is not alone in this problem. Some cities around the country’s capital have recorded similar, if not worse, pollution levels. The government has repeatedly promised to address the legacy of more than 30 years of industrialization, with coal-powered factories and car emissions being primary pollutants, but has done little to follow through.

Crossing the Pacific

Human health and wellbeing are not scientists’ only concerns regarding the addition of particle pollutants to the atmosphere. Although highly concentrated in China, the significant increase in particle pollutants is grounds for addressing the problem on a global scale. Meteorologists have become interested in high levels particle pollutants, as they could provide an answer to some of the observed changes in the global air circulation, the steady worldwide movement of winds that transports heat and energy to the poles.

Driven by energy from the Sun and the rotation of Earth’s axis, the global air circulation also significantly influences the formation, strength, and longevity of storms. Recent research by Texas A&M University and NASA’s Jet Propulsion Laboratory has confirmed an initial hypotheses that pollution from China influences global air circulation and, in turn, global weather patterns. The increasing number of particle pollutants in the atmosphere is altering the density of clouds and the amount of precipitation within them.

The research team from Texas A&M University and NASA’s Jet Propulsion Laboratory used a series of advanced climate models to decipher the current impact and future consequences of China’s excessive pollution on the global climate. Their results , published in the Proceedings of the National Academy of Sciences in April 2014, showed that once released into the atmosphere, particle pollutants interact with the atmosphere and in some areas, extend up to six miles high.

The lowest layer of the atmosphere, the troposphere, extends about 11 miles in the mid-latitudes from the base of Earth’s surface to the tropopause, a layer of air separating the troposphere from the second layer of the atmosphere, the stratosphere. The troposphere is the layer of the atmosphere where all weather occurs. A vertical extension of particle pollutants six miles high has an overwhelming influence on the formations of clouds and the weather.

Many storms that hit the US West Coast form in the mid-latitudes off the coast of Asia and track eastward across the Pacific Ocean. Under the influence of particles, storms have not changed their tracks, but they have intensified. Over time, the trend will ultimately lead to a change in climate for the US with an increased number of more intense storms. The intensification of storms that hit the US may not be the only climate-related result of China’s pollution problem. A single particle pollutant, released as exhaust from a truck, can travel almost 500 miles. That long reach allows for potentially damaging effects to occur in other parts of the world.

According to a Reuters report from early June 2014, China plans to set a cap on its fossil fuel emissions. The details on how they might do this are set to come out within the next year and take effect with China’s new five-year plan beginning in 2016. These environmental changes would be the first in more than 25 years and indicate that the environment has finally become a priority over continued economic growth.

Scientists will need to conduct further research to better understand the role particle pollutants have in atmospheric circulation and their impact on weather and climate. One thing is certain: Pollution is a major—and, if left unresolved, an increasingly global—problem.

Kristy Carter is a graduate student in the Department of Geography at the University of South Carolina in Columbia.