Explain the hypothesis of anthropogenic global warming.
Review the rollovers in the 'Are people the cause of climate change?' web page.

Explain the Greenhouse Effect.
Review the Greenhouse Effect web page.

The public often needs to take a position on technical issues, such as Climate Change, for which they have no expertise. Without acquiring the necessary expertise, how can they best go about developing a responsible, valid position?
Review the 'Reliability Criteria' and the 'Conclusions Panel Menu' web pages.

Storm Surge Recurrence Interval Graph.

The graph shown above describes the frequency of storm surges of different elevations for an area on the Hudson River just off the coast of downtown Manhattan.

  1. In the area referred to above, what percent chance is there in a given year that a storm surge will achieve an elevation of 15 feet?

    0.2 percent.

  2. What is the recurrence interval for that storm surge?

    500 years.

    Graph interpretation:

    Refer to the graph shown below.

    You have not studied dinosaurs in this course. Nevertheless, the following question will be a good test of your understanding of how graphs may be manipulated to support different arguments.

    A geologist used the graph shown above to argue that the extinction of the dinosaurs was due to the impact of a giant meteorite. The geologist pointed to the sudden nosedive in the numbers of dinosaurs that took place about 65 million years ago. He/she said that the abrupt disappearance of the dinosaurs was due to radical changes in the composition and temperature of the atmosphere brought about by the impact of the meteorite. Those changes caused all the dinosaurs to die in a matter of hours or days. A second geologist believes that the dinosaurs died out gradually. He/she opposes the meteorite hypothesis and has criticized the first geologist's use of the graph. In the space below, explain what the second geologist might say with reference to the graph to support his/her opposition to the meteorite hypothesis.

    The second geologist might point out that time is greatly compressed on the horizontal axis of the graph. If the time scale were expanded, it might be seen that in fact the dinosaurs did not all perish at the same time, but actually died out over many tens of thousands, hundreds of thousands, or even millions of years. (See the graph shown below.) On the graph the first geologist used, such relatively short times can't be discerned. (Actually, few geologists agree with the second point of view.)

    The graph shown below indicates the relationship between an organization's position on the Hypothesis of Anthropogenic Global Warming (yes = belief in the hypothesis; no = disbelief in the hypothesis) and the organization's reliability. State what the relationship is for the organizations plotted on this graph. Also state what conclusions a non-scientist should draw from the graph regarding the correctness of the hypothesis.

    The graph indicates that organizations that believe the hypothesis is correct are more reliable than those that don't believe the hypothesis is correct. In fact, the more reliable the organization, the greater is its belief in the hypothesis. In consequence, a non-scientist may feel justified in believing that the hypothesis of anthropogenic global warming is correct.

David J. Leveson