Rational numbers: {p/q | p and q are integers, and q =0}: Real numbers: {x | x is a number that can be written as a decimal}. Irrational numbers: {x | x is a real number andx cannot be written as a quotient of integers.}. Deï¬nitions: â¢ The number of elements in a set is called the cardinal number,orcardinality,oftheset. The symbol n(A), which is read ân of A,â represents the cardinal number of the setA.
The Intergovernmental Panel on Climate Change (IPCC) reported in 2014 that scientists were more than 95% certain that global warming is mostly being caused by human (anthropogenic) activities, mainly increasing concentrations of greenhouse gases such as methane and carbon dioxide (CO2).
The primary cause of global warming is the greenhouse effect. Like global warming, this is a natural phenomenon. As sunlight hits the earth, some of the heat is reflected back into space, while some is absorbed by green house gases â naturally occurring atmospheric gases such as carbon dioxide and methane.