(2007) concluded, with very high confidence, that regional temperature trends had already affected species and ecosystems around the world (p. 792). With high confidence, they concluded that climate change would result in the extinction of many species and a reduction in the diversity of ecosystems (p.
Full Answer. Use of the Gregorian calendar keeps the arrival of spring on March 20 or March 21 for most years, though sometimes spring arrives on March 19. According to National Geographic, in addition to the astronomical start of spring, a biological spring begins each year, usually on a different date.
In the Northern Hemisphere it commences on 20 June and ends on September 23. In the Southern Hemisphere it usually commences on 22 December. The end date is usually on the 23rd of March. Due to the rotation of the Earth, when it is summertime in one hemisphere it is winter on the opposite end. Keep in mind that these dates are only approximations. In some countries, the length of the summer season can be much longer. In some Southeast Asian countries, the season starts in late February and ends in June. Hot Weather. The most visible and widely felt element of the season is the heat.