(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.
Spring is the season of new beginnings. Fresh buds bloom, animals awaken and the earth seems to come to life again. Farmers and gardeners plant their seeds and temperatures slowly rise. The timing of these changes varies depending upon location. What most people call spring relies on the astronomical definition of the word. Spring is generally considered the period between the spring equinox and the summer solstice. Defined by the angle of Earth's tilt toward the sun, astronomical spring relies on equinoxes and solstices to define it. Equinoxes are special days during the year when day and night are almost equal.