During periods of frequent tectonic activity of the earth, new marine basins around Africa, South America, and Europe began to expand, creating new space. A large amount of carbon dioxide in the atmosphere reacted with photosynthetic organisms, and dead organisms were subsequently buried in seabed sediments. The formation of carbon-rich shales, the carbon in the atmosphere is fixed, which reduces the level of carbon dioxide in the atmosphere, reduces the greenhouse effect and lowers the global temperature, which is a very serious consequence for marine life. So scientists believe that the consequences of global cooling or warming are equally serious. Which of the following is true and best supports a scientist's diagnosis? ['00 years after global cooling, due to frequent volcanic eruptions, the carbon solidified in the rock leaves returned to the atmosphere in the form of carbon dioxide, which partially restored the greenhouse effect.', 'Global warming will lead to an ecological crisis in marine life, and scientists have found that a similar crisis occurred in marine life during a period of global cooling 260,000 years ago.', 'Large-scale and long-term natural changes, or huge changes in the global greenhouse effect in the short term due to human activities, have an impact on the entire system.', 'Scientists have observed that climate cooling has occurred over millions of years, not decades or centuries, which is difficult to associate with our rapidly changing modern climate conditions.']