 This amount of money is equivalent to gross national incomes for countries such as Russia or United Kingdom, and it represents 18% of United States' 2017 gross national income (19.61 trillion dollars).A change of temperature below 2 °C is, to certain extent, almost impossible to achieve due to the current carbon emission practices.The IPCC notes that it is difficult to assess a climate mitigation scenario that would limit average global temperature increase to only 1.5oC above pre-industrial levels.