Scientific Method Transcript
Welcome to the University of Waterloo video on the Scientific Method. Science and the Scientific Method attempt to describe and explain all of the landscapes, processes, features, and life we see on our planet. Using the Scientific Method is a way for us to attempt to understand the many inter-connections and relationships between the biotic and abiotic in the world around us.
The scientific method has been a vital part of humans’ evolution to become a dominant species on this planet. Whether it is understanding how germs and bacteria makes us sick, travelling and surviving through space and to the moon, or designing the next round of computer models to understand the physical or chemical processes we observe every day in the field or labs, we are using the scientific method. Let’s look at an important example of applying the scientific method, which spans across all science disciplines – climate change.
Observations
The first step in any scientific experiment or endeavor is to make observations. By observing the world and landscape around us, we may notice changes, or processes that seem new or interesting to study.
For example, scientists all over the world have observed and recorded changes in both the Earth’s atmospheric and ocean temperatures, which appear to be increasing at rates faster than seen at any time in recorded history.
They have also observed large-scale changes in the diversity and health of fresh and marine organisms throughout the global oceans and surface water sources. At the same time, scientists have observed that carbon dioxide (CO2) concentrations are quickly rising. This convergence of evidence is the first observation relating increased concentrations of greenhouse gases and higher temperatures.
Another observation is that polar and alpine ice cover is receding dramatically in both areal extent and total volume.
Species have been observed to be migrating to new areas not previous occupied, or occurring at new or different times of the year, in both flora and fauna populations.
Lastly, the world’s marine chemistry is also now being observed to slowly undergo change. The oceans have the ability to absorb most of the atmospheric carbon dioxide humans have released, which results in a decrease in pH – or acidification – over time. This dramatically affects the ability for marine microorganisms and other ocean life to build and maintain their exoskeletons and coral reef habitats, making them more vulnerable to predators, or other negative impacts in their natural environments.
Questions
The next step in the scientific method is to generate questions about the observations we have made regarding the feature, process, or reaction we are trying to learn more about. Based on the observations by scientists that we’ve just mentioned, some questions might be:
- Is climate change actually happening?
- Is climate change caused entirely by humans, or is there a natural component?
- How confident are we in our results?
- What will happen in the future if this continues?
Once we have generated an interesting question we would like to answer, we need to begin collecting information – or data.
So let’s choose the question, “Is climate change caused entirely by humans, or is there a natural component?
Research
If we want to find out if climate change is caused entirely by humans, we might begin by researching where all this extra observed CO2 might be coming from. Unfortunately, scientific research so far points to the main sources of atmospheric CO2 as the transportation, mining, and energy sectors of the developed world, which are vitally important for the everyday life and growth of human society. Cars and trucks, as well as planes and shipping vessels, are releasing large quantities of greenhouse gases from their exhausts each day, dwarfing the amount of carbon dioxide released by natural sources, such as volcanoes, or deep-sea hydrothermal vents over the same time spans.
Although CO2 is transparent to short-wave radiation or energy coming to Earth from our Sun, it is opaque to the long-wave radiation or thermal energy leaving the surface of the Earth. This long-wave radiation must then take a longer path to leave our atmosphere, allowing for more energy to build up, therefore causing the higher temperatures we observe.
Hypothesis
Now that we have recorded some observations and asked some questions, and completed some additional research to fill out any knowledge gaps we might have about the process we are studying, the next step is to formulate a formal Hypothesis. A hypothesis is like an educated guess or statement to explain a phenomenon or an attempt to answer a specific question in Science.
For climate change, a good testable hypothesis could be:
The additional increase of anthropogenic carbon dioxide to the composition of our atmosphere will cause a continued increase in both global atmospheric and ocean temperatures into the future.
Prediction
Based on our hypothesis, we could predict that “Increasing the amount of CO2 in the atmosphere will cause it to warm up.
Test and Experiment
The next step is to test your hypothesis with a series of experiments by gathering evidence and data, both qualitative and quantitative, related to your questions, observations, and research.
To test our hypothesis that increased carbon dioxide in our atmosphere is causing it to warm up, we will place four glass jars with varying concentrations of atmospheric air and carbon dioxide outside in direct sunlight for several hours. The first jar will be open, to provide a control on air temperatures. The second jar will be sealed, containing our normal atmospheric composition. The two remaining jars will also be sealed, and in each of these jars we’ll increase the CO2 concentration to higher levels.
Within each jar, we will also place a digital thermometer which can be easily read from the outside to monitor any change in temperatures. After each successive hour in direct sunlight, we’ll return to read and record the temperature of each jar. Careful records of both temperature and time passed will allow us to graph the results for a more visual representation, which can help make the results easier to understand.
Lastly, remember that it is important to repeat our experiment several times to attempt to eliminate any bad or biased results.
Results and Conclusions
After several hours in direct sunlight, we find that the jar with the highest concentration of CO2 resulted in the largest increase in temperature. Therefore, from the experimental evidence, we can conclude that: adding additional carbon dioxide from various energy, mining, transportation, or industrial sources is having a direct and quantifiable impact on the temperature of Earth’s atmosphere.
This in turn is warming the oceans and melting the polar and alpine regions, as well as increasing the acidity of atmospheric water, which is then transferred to the world’s oceans and soils, altering their chemistry and negatively impacting ecosystems worldwide.
Therefore, properly utilizing the scientific method directs us to the solution of this major global problem – which is to encourage the global reduction of all carbon dioxide sources, and promote the use of sustainable and clean renewable transportation, energy, and mining technology.