<span>In the 19th century, scientists realized that gases in the atmosphere cause a "greenhouse effect" which affects the planet's temperature. These scientists were interested chiefly in the possibility that a lower level of carbon dioxide gas might explain the ice ages of the distant past. At the turn of the century, Svante Arrhenius calculated that emissions from human industry might someday bring a global warming. Other scientists dismissed his idea as faulty. In 1938, G.S. Callendar argued that the level of carbon dioxide was climbing and raising global temperature, but most scientists found his arguments implausible. It was almost by chance that a few researchers in the 1950s discovered that global warming truly was possible. In the early 1960s, C.D. Keeling measured the level of carbon dioxide in the atmosphere: it was rising fast. Researchers began to take an interest, struggling to understand how the level of carbon dioxide had changed in the past, and how the level was influenced by chemical and biological forces. They found that the gas plays a crucial role in climate change, so that the rising level could gravely affect our future. (This essay covers only developments relating directly to carbon dioxide, with a separate essay for Other Greenhouse Gases. Theories are discussed in the essay on Simple Models of Climate.)</span>
Answer:
in a laboratory
Explanation:
A controlled experiment refers to the one where everything is an experiment except a single variable is held constant. A collection of information is typically taken as a control group, which is generally the ordinary state, and another group is analyzed( such as chemical reaction as per the question) in which all conditions are similar to the control group except for the variable under examination. The main benefit of a controlled experiment is that confusion over the accuracy of the results can be eliminated more easily.
Humans directly impacted the environment by destroying of the habitat of the other plants. Hence, option B is correct.
<h3>What is Kudzu plant?</h3>
Kudzu vine is known as a fast-growing plant since the '30s and 40's when the Soil Conservation Service paid about 8$ to every farmer who can plant an acre with this plant.
Kudzu overgrows and crowds out native plant population, for sunlight and nutrients. Therefore, it's considered 'invasive'.
It grows so quickly that it cannot be controlled and disturb other habitats of plants. Hence, option B is correct.
Learn more about kudzu vine here:
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