During the period when the Earth's tectonic activity was frequent, 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 the dead organisms were subsequently buried in the bottom sediment In the formation of shale rich in carbon, carbon in the atmosphere is fixed, which reduces the level of carbon dioxide in the atmosphere, reduces the greenhouse effect and lowers global temperature, which is a very serious consequence for marine life. Therefore, 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 during the period of global cooling 260,000 years ago, marine life experienced a similar crisis.', '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 hundreds of years, which is difficult to associate with our rapidly changing modern climate conditions.']