The hole in the ozone layer over Antarctica will disappear by 2040, Japanese scientists forceasted yesterday, offering a far more hopeful timeline than previous reasearch predictions.Using a supercomputer to model future global atmospheric conditions, scientists Tatsuya Nagashima and Masaaki Takahashi from Toyko University predicted that the next 15 years will see little or no change in the size of the ozone hole before a slow improvement begins in the late 2030's. From that point on there will be a sudden increase in the amount of ozone into the stratosphere, leading to a full recovery by about 2040.