What time frame is considered rapid environmental change?

less than a decade

more than a century

less than a year

more than two generations

The correct answer is option - C, less than a year

The Earth is changing very fast due to the rapid rate of changing climatic conditions within it as caused by both natural and man-made factors but usually these changes occurs across several years. Now when the climatic variations can be visualized even in a time frames less than a year, we can say that the environment is changing excessively faster than its previous records. However, till date we have been considering the climate changes with in a period of 10 decade as a time frame for rapid environmental change. But considering the daily undulations of weather these days, a change in environment with in a smaller time frame “ less than a year shall be considered”.  

a

explanation:

what is this saying?