Young Earth creationism (YEC) is the religious belief [Eugenie, 2004] that the Universe, Earth and all life on Earth were created by direct acts of the Abrahamic God during a relatively short period, sometime between 5,700 and 10,000 years ago. [Ibid, 2006] Its primary adherents are those Christians and Jews [Barry Freundal, 2004] who, using a literal interpretation of the Genesis creation narrative as a basis, believe that God created the Earth in six 24-hour days.[Grifith, 2007].
The scientific consensus, supported by a 2006 statement by 68 national and international science academies, is that it is evidence-based fact derived from observations and experiments in multiple scientific disciplines that the universe has existed for around 13.8 billion years and that the Earth was formed about 4.5 billion years ago, with life first appearing at least 2.5 billion years ago.[Wiki] Although many young Earth creationists (YECs) are active in the development of creation science, an endeavor that holds that the events associated with supernatural creation can be evidenced and modeled through an interpretation of the scientific method, the consensus among scientists is that creation science is unscientific in both conception and methodology.[Overton, 1982)]
A Gallup Pole demonstrated that the percentage of "Young Earth" believers decreases as the level of education increases.
Lack of scientific acceptance From Wiki (I edited down a bit):
Young Earth creationism was abandoned as a mainstream scientific concept around the start of the 19th century. Most scientists see it as a non-scientific position, and regard attempts to prove it scientifically as being little more than religiously motivated pseudoscience. In 1997, a poll by the Gallup organization showed that 5% of US adults with professional degrees in science took a young Earth creationist view. In the aforementioned poll, 40% of the same group said that they believed that life, including humans, had evolved over millions of years, but that God guided this process, a view described as theistic evolution, while 55% held a view of "naturalistic evolution" in which no God took part in this process. Some scientists (such as Hugh Ross and Gerald Schroeder) who believe in creationism are known to subscribe to other forms such as Old Earth creationism which posits an act of creation that took place millions or billions of years ago, with variations on the timing of the creation of mankind.
Another problem is the fact that distant galaxies can be seen. If the universe did not exist until 10,000 years ago, then light from anything farther than 10,000 light-years would not have had time to reach us. Most cosmologists accept an inflation model as the likely explanation for the horizon problem. Inflationary models also account for other phenomena, and are in agreement with observations of recent microwave anisotropy satellites.
Against the young Earth Creationist attacks on "evolutionism" and "Darwinism", critics argue that every challenge to evolution by YECs is either made in an unscientific fashion, or is readily explainable by science, and that, while a gap in scientific knowledge may exist now, it is likely to be closed through further research. While scientists acknowledge that there are indeed a number of gaps in the scientific theory, they generally reject the creationist viewpoint that these gaps represent fatal, insurmountable flaws with evolution. Those working in the field who pointed out the gaps in the first place have often explicitly rejected the creationist interpretation. The "God of the gaps" viewpoint has also been criticized by theologians and philosophers.
The bottom line is that there is no evidence for a "Young Earth" Creationism Model. On the other hand, old Earth creationists have demonstrated how the Earths actual age can be consistent w/ a belief in God.