NEW DELHI: Noting that air pollution has reached crisis level in Northern India , government think-tank Niti Aayog has recommended a slew of measures like imposing higher taxes on petrol in and around the more polluted cities to encourage commuters to share cars and take public transportation.The Aayog, in its 'Three Year Action Agenda to be implemented till 2019-20' and released by Finance Minister Arun Jaitley , also suggested making public transportation faster and more comfortable to discourage the use of private vehicles.It has identified coal power plants, brick kilns, vehicles, cooking and heating fires which burn biomass, rubbish burning and burning of crop residue and dust from construction as the "major" source of air pollution.It noted that air pollution has reached crisis levels in Northern India and though it is much publicised in Delhi, it is also widespread in many other cities and as many as ten of the top 20 most polluted cities in the world are in India.It recommended actions like finding alternatives to crop residue burning, reducing pollution from cooking fires and installing flu gas de-sulpherizers on all coal power plants in or close to densely populated areas except those less than 5MW capacity and those older than 25 years by 2020.It also suggested switching to cleaner technologies to reduce pollution from brick kilns considerably within three years."A number of complementary steps can be taken (to reduce in-city-vehicle pollution). First making public transportation faster and more comfortable will discourage the use of private vehicles."Metro or bus based rapid transit systems connecting suburbs and city centre and a dense in-city transport system will go some distance towards achieving the objective," it proposed.It also talked about replacement of vehicles from petrol and diesel to CNG, infrastructure improvements which allow vehicles travelling long distances to bypass the cities without entering, higher taxes on petrol to encourage commuters to share cars and other measures to cut emissions."Higher taxes on petrol in and around more polluted cities would encourage commuters to share cars and take public transportation."Higher parking fees and park and ride facilities will have similar effects," it recommended.As far finding alternatives to crop residue burning was concerned, the document noted that 'Happy Seeder', a machine developed by Commonwealth Scientific and Industrial Research Organisation (CSIRO Australia) and Punjab Agricultural University, allows planting of wheat through the residue.It said that the machine was introduced about five years ago and has been shown to reduce field preparation costs marginally and maintain yields and profits of wheat, which has led some farmers to adopt it."In view of the urgency of the problem and the large benefit from putting an end to crop residue burning, a larger subsidy on the machine for limited time complemented by extension and information campaigns may eliminate the problem within the next three years," it said.It also suggested installation of Flue-gas De-sulphurizers on all coal power plants in or close to densely populated areas except those less than 5 MW capacity and those older than 25 years by 2020.The older power plants should be shut down and retired in a phased manner, it said while adding that this will cut emissions of Sulphur Dioxide (SO2) gas that becomes sulphate particles in the atmosphere."It will also reduce particulate (smoke) emissions directly."The average cost of doing this along with improvements in fly ash removal and control of Nitrogen Oxides (NOx) emissions has been estimated to be 35-40 paise/KWh, and could reduce the PM2.5 concentrations by 30-40 per cent," it recommended.