The critical difference between today's global warming and earth's previous climate changes is that
human-made chemicals such as cfcs do not influence global warming.
previous changes in climate were dramatic but very short-lived.
scientists can now save all species from extinction by genetic engineering.
global warming may occur much more rapidly than it did during previous climate changes due to rising carbon dioxide levels.

previous changes in climate were dramatic but very short-lived.


The issue of whether human activities cause global climate change is indeed a controversial topic. The limitation to climate research that could be overcome through scientific design is "Data from a wide range of time periods must be analyzed." Very powerful, or Super Computers, are required to analyze large amounts of data. The sooner more powerful computers are developed, the sooner data from the wide range of time periods can be analyzed. This will give scientists a better idea of the extent of global warming, if any, and how to prevent it.

The answer is c : ) hope this answered your question!