Introduction:

Global Warming, apart from pollution, is one of the biggest concerns that scientists have. It’s the process that continuously warms the Earth, leading to an increase in the temperature. Over the past century, the Earth’s surface temperature has risen by about one degree Fahrenheit, with a more rapid increase in the past three decades. There is now stronger evidence that human activities are mostly responsible for this warming. Through the buildup of greenhouse gases, such as carbon dioxide, methane, and nitrous oxide, human activities have altered the chemical composition of the atmosphere and the environment, which is the main cause of Global Warming.

Four Steps in the Greenhouse Effect:

The Greenhouse effect operates in four steps:

1. Ultraviolet rays from the sun pass through space and enter Earth’s atmosphere.
2. The sunlight hits Earth’s surface, converting some of it into heat energy in the form of infrared light.
3. The heat is absorbed by the surrounding air and land, making the temperature rise.
4. Infrared rays that are emitted into the atmosphere are captured by greenhouse gases. These gases absorb the rays and send them back to the Earth’s surface, further warming it.

According to the National Academy of Sciences, the Earth’s surface temperature has risen by about one degree Fahrenheit in the past century, with a more rapid increase in the last two decades. There is now new and stronger evidence that human activities are mostly responsible for the warming over the last 50 years. Human activities have changed the chemical composition of the atmosphere through the buildup of greenhouse gases – primarily carbon dioxide, methane, and nitrous oxide. The heat-trapping property of these gases is widely recognized, although there are still uncertainties regarding how exactly the Earth’s climate responds to them.

Methane and Carbon Dioxide as Greenhouse Gases:

Methane and carbon dioxide are naturally occurring greenhouse gases that help regulate the Earth’s temperature, making it suitable for humans to live on. However, the concern is that human-enhanced processes are further intensifying the Greenhouse effect and leading to Global Warming. In recent years, the emissions of greenhouse gases have multiplied due to the rapid technological advancement achieved by humans. Industrial activities, like factories, are among the major sources of these dangerous gases, including methane, carbon dioxide, nitrous oxide, and ozone-depleting substances such as CFCs, hydro-fluorocarbons, chlorofluorocarbons, and per-fluorocarbons.

Essentially, global warming is the result of the increasing temperature of the Earth’s surface due to the presence of chemicals in the atmosphere. The threats posed by global warming are diverse, affecting the Earth’s climate, human health, and even the seasons of crops. Furthermore, global warming has significant impacts on the survival of various organisms on the planet.

Signs and Effects:

A considerable portion of the United States is expected to experience warming, although the presence of sulfates may limit the degree of warming in some areas. Scientists currently cannot determine which regions of the United States will become wetter or drier, but there is a general trend towards increased rainfall, evaporation, stronger thunderstorms, and drier topsoil.

Unfortunately, many of the potential consequences depend on whether rainfall increases or decreases, which cannot be reliably predicted for specific regions. Global warming also leads to the melting of glaciers in the Arctic and Greenland, causing a rise in sea levels worldwide. In the past century alone, global sea levels have risen by four to ten inches, representing a significant change.

Health:

Climate significantly influences the occurrence of specific diseases and poses additional risks to human health. Extreme heat can directly cause fatalities, and certain diseases are more prevalent in warm regions. Elevated temperatures can also exacerbate air and water pollution, leading to detrimental effects on human health.

The direct impact of climate change primarily involves the influence of higher temperatures themselves. Extremely hot temperatures increase the number of deaths on a given day for various reasons. Individuals with heart problems are particularly vulnerable as their cardiovascular system has to work harder to regulate body temperature during hot weather. Heat exhaustion and respiratory issues are also more likely to occur.

Higher air temperatures also lead to increased ozone concentration at ground level. While ozone in the upper atmosphere protects from harmful ultraviolet radiation, at lower levels, it becomes a dangerous pollutant. Ozone damages lung tissue and poses significant risks to individuals with asthma and other respiratory conditions. Even mild exposure to ozone can cause chest pains, nausea, and pulmonary congestion. A warming of four degrees Fahrenheit could potentially increase ozone concentration by about 5 percent in many parts of the country.

Statistics on mortality and hospital admissions indicate that death rates rise during extremely hot days, particularly among the elderly and young individuals living in urban areas. For example, a heatwave in July 1995 claimed the lives of over 700 people in the Chicago area alone. Based on these statistics, studies estimate that in Atlanta, even a two-degree warming could lead to an increase in heat-related deaths from the current 78 per year to a range of 96-247 per year. If people can adapt to hotter temperatures by installing air conditioning and making other adjustments, the lower estimate is more plausible.

Warmer temperatures may reduce the number of deaths caused by cold weather each year. However, in the United States, only 1000 people die from the cold annually, compared to twice that number from heat-related causes.

Nasty Surprises:

The Earth’s response to global warming can be both gradual and rapid. By continuing to emit greenhouse gases, we may face unexpected and undesirable changes.

Escaping Methane:

As the Arctic warms, significant amounts of methane currently locked in the ocean and land ice may be released into the atmosphere. Methane is a potent greenhouse gas that traps heat, and these additional emissions could result in a faster and more severe warming than currently anticipated.

Water Resources:

Climate change is expected to increase both evaporation and rainfall in major regions of the United States. In regions where evaporation exceeds rainfall, the soil will become drier, lake levels will drop, and rivers will carry less water.

Reduced river flows and lower lake levels can hinder navigation, hydroelectric power generation, and water quality, while decreasing the availability of water for agriculture, residential, and industrial uses. Some regions may experience increased flooding during winter and spring, coupled with reduced supplies in summer. For instance, in California’s Central Valley, where snowmelt provides a significant portion of the summer water supply, warmer temperatures would cause the snow to melt earlier, reducing summer water availability, even if spring rainfall increased. Additionally, the trend of more concentrated rainfall in heavy storms as temperatures rise is likely to increase river flooding without increasing water availability.

Food and Water:

Some regions may benefit from warming as it could lengthen the growing season and shift agricultural zones northward. Crop production would increase in northern Europe and Canada.

However, soils in continental areas may become drier during summer. Coupled with global warming, these drier conditions could result in lower crop yields. Corn production in the United States, for example, may decrease due to this trend.

Warming could cause earlier snowmelt in mountains, altering the timing of water storage in reservoirs, increasing the risk of spring flooding, and reducing water supplies in summer.

Changes in climate zones may introduce new crop pests to certain areas, while more livestock could become susceptible to diseases.

Changes in Global Harvest:

Climate change is expected to have the most significant impact on global food supply and demand, as heat, light, and water are the primary drivers of agricultural production. Regions that already struggle to produce enough food in the present may be particularly vulnerable to further damage.