London, March 12- If the price of oil decreases, carbon dioxide (CO2) emissions increase, says a new study suggesting a need to design new energy taxes for the conservation of environment. The results of the study have revealed that a one percent increase (or decrease) in the oil prices has been responsible for a reduction (or rise) in the CO2 emissions equal to about 0.4 percent. "It is well known that an increase in oil prices may lead to a reduction in energy consumption," said Manuel Cantavella researcher at Jaume I University in Spain, adding that oil is the second most polluting fuel just behind coal. However, experts have argued that an improvement in per capita income would reduce the level of environmental degradation. Thus with the effects of per capita income, there is room to apply specific measures aimed at improving the environmental quality, the authors noted. For the study, published in the journal Ecological Indicators, the scientists compared the relationship between air pollution and economic development by using the real oil prices in Spain between 1874 and 2011 as an indicator. The data was gathered from the Statistical Review of World Energy 2013. The researchers stressed the need for a cautious green tax structure that would reduce the overall consumption of fossil fuels and promote the user of cleaner and more efficient energies.