It is known that the climate and the terrestrial biosphere affect each other. This is because pants use sunlight as food and rain as water. In terms of vegetation, it converts the sunlight into heat fluxes that it used between the soil and the atmosphere and the rain gets stored in the soil as water. This interaction between the climate and vegetation can be so strong it can cause regime shifts to occur within the ecosystem. Recent research has been done on what extent does plant diversity influence the stability of climate-vegetation interaction. It was found that the Sahara desert was much greener several thousand years ago than it is today. Researcher Martin Claussen along with his colleagues hypothesized that the Sahara desert much has expanded to its present size within just a few hundred years. In their study, they examined how the plant diversity affects the dynamics of climate-vegetation interaction. As a result, it was found that some plant types are sensitive to changes in precipitation that causes an unstable vegetation-climate system. If the climate reminds precipitated it can cause the sensitive plants tend to die off because they are not “fit” for the current environment. On the other hand, other plant types that tend to be more drought-resistant and more resilient to minor changes in precipitation causes a stable vegetation-climate system. If both plant types interact with the climate simultaneously, then plant diversity will have less of an effect on the instability of the interaction between climate and vegetation. Currently, the system shows strong fluctuations within the climate-vegetation interaction but no occurrence of abrupt changes. Interestingly enough, the “vegetation-climate” system also stabilizes if sensitive plant types, distinguishing themselves only by different thresholds. For instance, some plant types are sensitive to minor changes in precipitation that occur in humid climate while others can survive on a limited amount of water, but react quickly with the onset of aridity. However, this system may seem stable but it actually hides its instability. Moreover, if some plant types were removed or introduced, an abrupt shift in vegetation cover and precipitation can occur. This study provides a possible explanation for the shifts that occurred in vegetation and climate in northern Africa several thousand years ago.