The atmospheric chemistry would be upset by cutting out sunlight. It would be like a nuclear winter and could last for tens of thousands of years. These comets are 200-300km (186 miles) in diameter they are sheer monsters and could sterilise the earth if we are hit by one.
Heat stress â Another reason for rose leaves turning yellow is the rose bush is under some sort of stress. A common cause of stress is heat stress. The rose bush turns yellow and drops its foliage in an effort to cool down in the case of heat stress.
Chlorosis â The reason why leaves are turning yellow could be an abnormal condition called chlorosis. Chlorosis is when the yellow leaves are missing the green pigment called chlorophyll. There are specific causes why plant leaves turn yellow due to chlorosis.f you have houseplants that have yellow leaves, check the soil in the pot to see if it is dry. If you find this is why leaves are turning yellow, simply water the plant and consider leaving the pot to sit in a dish to catch overflow and allow the roots to absorb the extra water when needed. Advertisement.