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).
Human causes. Climate change can also be caused by human activities, such as the burning of fossil fuels and the conversion of land for forestry and agriculture. Since the beginning of the Industrial Revolution, these human influences on the climate system have increased substantially.