Reuters: U.N. Secretary-General Ban Ki-moon said on Thursday he would push at a Group of Eight summit next month for short- and medium-term goals for cutting greenhouse gases and also urge a big rise in agricultural aid. Ban told journalists that before setting out on an Asian tour that will include this year’s July 7-9 G8 summit in Toyako, Japan, he would write to each of the group’s leaders “laying out my concerns and requesting their leadership.” The G8 nations are Britain, Canada, …