Eunice Foote: The first person who told about greenhouse effect
Eunice Newton Foote (1819-1888) was an American scientist who was the pioneer to experimentally prove that carbon dioxide and water vapor are responsible for greenhouse effect. She was also an inventor and women’s rights campaigner.
Eunice Newton Foote conducted an experiment to show that water vapor and carbon dioxide trap heat. Based on her experiment, she predicted that a rising concentration of these gases would result in climate change on the earth.
Let us try to understand greenhouse and its effect. You will also learn about the experiment conducted by Eunice Foote.
What is Greenhouse?
An enclosure specially made to trap heat is called a greenhouse. Greenhouses have been in use since the times of the Roman Empire. The first greenhouse was built in Rome around 30 BC. When the emperor Tiberius fell sick, the royal physicians advised him to eat cucumber to restore health. But it was not possible to grow cucumber all around the year. An artificial environment was created to grow cucumber so that the emperor could get his regular dose of cucumber. That is how the first greenhouse was created in the history.1
Construction of Greenhouse
Now-a-days, greenhouse is usually made up rigid frames and transparent covering is wrapped around the frame. The frame can be made of plastic, metals or wood. The transparent material can be made from plastic or glass.
Working mechanism of greenhouse
A greenhouse gets heat from solar radiation and also from the earth’s radiation. Whatever heat the earth gets from the sun is reflected back in the form of earth’s radiation. The atmosphere prevents most of this heat from escaping back into the space. An ambient temperature is maintained on the earth due to this.
The heat that is trapped inside the greenhouse raises the temperature inside the greenhouse. This keeps the atmosphere inside the greenhouse warm enough for plants to grow and to make food through photosynthesis. Thus, greenhouses enable people to grow crops even in cold climate.
Ventilation in greenhouse
A greenhouse is not a watertight compartment rather it has provisions for ventilation as well. If a greenhouse would be made watertight or airtight, it will cause more harm than good for the plants. Plants also need oxygen-rich air to breathe. In addition to a supply of fresh air, plants also need agents of pollination to produce seeds and fruits. So, suitable ventilation is provided in a greenhouse.
Eunice Foote’s Experiment
Eunice Foote used two containers of the same size to conduct the experiment. She vacuumed the air out of one container and filled that with carbon dioxide. The second container had air inside. She inserted a thermometer in each container. After that, she kept the containers in sunshine for a certain period of time to observe the effect. She repeated this experiment by filling water vapor in the first container instead of carbon dioxide.
Eunice Foote observed that the temperature of the container (with carbon dioxide or water vapor) was higher than the temperature of the container (with air). She repeated the experiment by keeping the containers in shade and could make similar observations.
Eunice Foote published a paper in 1856, on the basis of her experiments. The title of her paper was, Circumstances Affecting the Heat of the Sun's Rays. He paper was published in the 1856 edition of American Journal of Science and Arts.
Rediscovery of Eunice Foote’s Findings
Foote’s findings fell into oblivion because of the inherent bias against women scientists. It was in 1976, when a historian gave credit to Foote’s discovery. Roland Jackson analyzed Foote’s work in 2019. Ralph Lorenz evaluated Foote’s work in the modern context of planetary climate. Joseph D Ortiz (Kent State University) and Jackson analyzed Foote’s work and published a paper in 2022. All these scientists considered other factors which play important role in planetary climate. They made an opinion that Foote’s experiment had certain shortcomings.2
But one should not forget the limited resources and knowledge which were available during Eunice Foote’s time. Keeping such constraints in mind, one can safely say that Eunice Foote was the true pioneer to experimentally prove and predict the effects of greenhouse gases when the Industrial Revolution was in its nascent years.
Greenhouse Effect and Global Warming
Effects of global warming have become so apparent that they cannot be ignored by anybody. We are witnessing dramatic changes in weather patterns all over the world. Summers are getting unbearably hot and winters are getting freezing cold. People are witnessing hailstorms even in deserts. Many states of India which earlier suffered from severe drought have witnessed flash floods in recent years.
Many scientists had started to talk about the harms of burning coal as early as the beginning of the nineteenth century. Causes and effects of global warming are taught to students, right from the middle school. There are many environmental activists who continue to raise awareness and concern about this pressing problem. But irony of all such activisms is that when the world leaders meet for a conference to address the problem, each of them travels by his/her personal airplane and end up burning thousands of liters of fossil fuel in the process.