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).
Global Warming is Human Caused. Scientists have concluded that most of the observed warming is very likely due to the burning of coal, oil, and gas. This conclusion is based on a detailed understanding of the atmospheric greenhouse effect and how human activities have been tweaking it.ome of that heat is trapped by greenhouse gases in the atmosphere, including carbon dioxide (CO2). Human activity--such as burning fossil fuels--causes more greenhouse gases to build up in the atmosphere. As the atmosphere thickens with more greenhouse gases, more heat is held in.