Whether you are looking to learn more about the greenhouse effect or you are wondering what it is, this article can help you understand some of the important aspects of the greenhouse phenomenon. It discusses some of the major greenhouse gases and the human activities that are affecting them. It also explores some of the risks and consequences associated with the greenhouse phenomenon.
Carbon dioxide
Throughout Earth history, atmospheric carbon dioxide levels have fluctuated dramatically. They have never reached the levels they currently are. However, there is a lot of scientific evidence that the concentrations were higher during warm periods in the past.
The amount of CO2 in the air has increased over the last sixty years. This has had profound consequences for life on Earth. The ozone layer is weakened and the average temperature of the Earth has been rising. Without the greenhouse effect, the temperature of the Earth would be -18 deg Celsius.
The Vostok core was a significant step towards a consensus on the effects of CO2. It showed that the climate and the carbon cycle are part of a planetary system.
The most obvious implication of the Vostok core is that CO2 is a major contributor to global warming. The average annual rate of increase in atmospheric CO2 over the last 60 years is about 100 times faster than previous natural increases.
Water vapor
Among greenhouse gases, water vapor is the most important. It combines with CO2 to add heat to the atmosphere. This heat is then released in the form of evaporation. Its resulting warming exacerbates the effects of climate change.
Aside from its direct effect on temperature, water vapor is also important for atmospheric circulation. In fact, it is involved in an important feedback loop. For example, an increased number of clouds increases the albedo (reflectivity) of the Earth’s surface. This in turn increases the amount of energy that is absorbed by the atmosphere.
In terms of the water vapor-warming-coupled-with-CO2 relationship, we can see that increasing temperatures increase the holding capacity of the air. This holds 4% more water vapor for each degree Fahrenheit of temperature increase. However, this capacity is very sensitive to temperature.
Influential gases
Several gases in the Earth’s atmosphere have the capacity to absorb infrared radiation. This is known as the greenhouse effect. As greenhouse gas concentrations increase, the temperature of the planet rises. This raises the risk of air pollution and heat-related illnesses. It also increases the risk of flooding and droughts.
The most important gases are water vapour and carbon dioxide. Other gases have a lesser ability to absorb infrared radiation. These gases can be produced naturally or by human activity.
Water vapor has the strongest greenhouse effect. Its absorption capacity is directly related to the temperature of the atmosphere. As the temperature rises, water vapour increases.
Another greenhouse gas is methane (CH4). Methane is a gas with four hydrogen atoms and one carbon atom. It is formed when bacteria decompose organic matter. Methane has a shorter residence time in the atmosphere than CO2. However, it has a stronger ability to absorb infrared radiation. Its absorption capacity is 30 times greater than CO2.
It is generated in sewage treatment plants, landfills, and wetlands.
Human activities
During the last 150 years, human activities have dramatically increased the amount of greenhouse gases in the atmosphere. These gases trap heat from the sun and the Earth. They are released into the atmosphere by industrial processes, land clearing and agriculture. The most common greenhouse gas is carbon dioxide.
The most important sources of greenhouse gas emissions are burning fossil fuels and deforestation. These activities have increased the amount of CO2 in the atmosphere by more than 80 percent during this period.
Other important sources of greenhouse gases include methane and nitrous oxide. Methane is a potent greenhouse gas that is stronger than CO2. It is produced by livestock farming, fossil fuel extraction and organic waste in landfills. It is also released when natural gas and oil are transported. Similarly, nitrous oxide is a powerful greenhouse gas that is released by nitrogen-containing fertilisers.
Runaway greenhouse effect
Generally speaking, the runaway greenhouse effect is a scenario that occurs when a planet’s atmosphere becomes overloaded with greenhouse gas. It causes rapid warming that can lead to the complete vaporization of liquid water on the planet’s surface. In some cases, the planet can experience a hothouse-like atmosphere, in which the surface temperature can reach hundreds of degrees Fahrenheit.
The ominous signs of a runaway greenhouse can be seen in Venus. Scientists have found that the Venutian atmosphere is filled with carbon dioxide, nitrogen dioxide, and water vapor. They estimate that the global mean temperature on Venus is around 450oC. The atmosphere contains about 97 percent CO2 and traces of nitrogen dioxide.
A recent study by scientists at NASA Ames found that water vapor in the upper reaches of the atmosphere can contribute to a runaway greenhouse signature. The researchers used data from Earth Observing System satellites and a model called MODTRAN.
