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.
By Kathleen Mierzejewski. When you have plants, whether indoor or outdoor, the leaves can suddenly start turning yellow. Yellowing leaves on your plants may point to something being wrong with your plants. Why plant leaves turn yellow is a tricky question.There are plenty of reasons that might cause yellow leaves on your plants.hlorosis 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.