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.
Moisture Stress. The most common reason that plantsâ leaves turn yellow is because of moisture stress, which can be from either over watering or under watering. If you have a plant that has yellow leaves, check the soil in the pot to see if the soil is dry.If you believe that the problem is due to under watering, water the plant more often and consider letting the pot sit on a dish to recollect any water that has overflowed, so that the roots can absorb the extra water.ight. Another common reason that plantsâ leaves turn yellow is because not enough light is reaching the plant. This occurs because the rate of photosynthesis is limited in low light, but as the light is increased, photosynthesis increases as well.