Although it is a worldwide treaty, the Kyoto Protocol has received criticism. Criticism of the Kyoto Protocol Some also argue the protocol does not go far enough to curb greenhouse emissions and avoid dangerous climate change (Niue, The Cook Islands, and Nauru added notes to this effect when signing the protocol). Some environmental economists have been critical of the Kyoto Protocol. Many see the costs of the Kyoto Protocol as outweighing the benefits, some believing the standards which Kyoto sets to be too optimistic, others seeing a highly inequitable and inefficient agreement which would do little to curb greenhouse gas emissions. There are also economists who believe that an entirely different approach needs to be followed than the approach suggested by the Kyoto Protocol. In Russia, Andrey Illarionov, who was an economic policy advisor to the President of Russia, Vladimir Putin, expressed the opinion that since human civilization is based on the consumption of hydrocarbons, the adoption of the Kyoto agreements could have a negative impact on Russian economy. He regarded the Kyoto agreement as discriminatory and not universal, since the main sources of carbon dioxide emissions like the US, China, India, Brazil, Mexico and Korea, as well as a number of developing countries, did not impose any restrictions on themselves. Andrei Illarionov also referred to a large number of works that cast doubt on the very idea of a "greenhouse" effect caused by the accumulation of carbon dioxide. Base year as 1990 controversy Further, there is controversy surrounding the use of 1990 as a base year, as well as not using per capita emissions as a basis. Countries had different achievements in energy efficiency in 1990. For example, the former Soviet Union and eastern European countries did little to tackle the problem and their energy efficiency was at its worst level in 1990, the year just before their communist regimes fell. On the other hand, Japan, as a big importer of natural resources, had to improve its efficiency after the 1973 oil crisis and its emissions level in 1990 was better than most developed countries. However, such efforts were set aside, and the inactivity of the former Soviet Union was overlooked and could even generate big income due to the emission trade. There is an argument that the use of per capita emissions as a basis in the following Kyoto-type treaties can reduce the sense of inequality among developed