A recent study by the National Environmental Engineering Research Institute has projected that in 2051, carbon dioxide emissions in residential areas are likely to go up to 51 million tonne compared to the current 15 million.

Similarly, carbon dioxide emitted from vehicles is likely to increase to 81 lakh tonne from the current 37 lakh. The study was carried out to understand housing and transport issues with regard to energy and environment and its links with climate change.

Energy consumed in residential areas amounts to 24% of total consumption in the country, second only to industries that eats up 37%. The agricultural and commercial sectors consume 22% and 10% of energy, respectively. Environmental experts believe that development and use of energy efficient technologies for cooking, heating, lighting, electrical appliances, and building insulation in developing countries like India has been poor, leading to high amount of consumption.

The key findings of the study showed that both fuel and journey time increase in peak traffic. Carbon dioxide emissions increased by 33-75% when travel time was up by 5-30 minutes.

Terming it as a possible "energy crisis" if not tackled in time, environmentalists believe that carbon offset programmes are needed to be chalked out to find ways to save energy. The study looked at Thane, Navi Mumbai, Kalyan, Dombivli, Ulhasnagar, Ambernath, Panvel, Alibag, Virar, Vasai, Nala Sopara, Mumbai and so on.

The energy consumption in non-slums areas of MMR is more than in the slums of these regions. The highest energy usage is by refrigerators and geysers, while in the slums it is iron box and refrigerators. Going by the current standards, there is likely to be a six-fold increase in the total energy demand from the housing sector by 2051—the present demand of 1,931MW per day is expected to go up to 6,680MW.

The study has seen that appliances using highest electricity in Greater Mumbai are refrigerator, geyser, iron box, ceiling fan and television set, while in the rest of the corporations, it is refrigerator, incandescent light bulb and iron box. In municipal councils, it is refrigerator, iron box and ceiling fans that have the highest consumption.

"We need to think of a policy to offset carbon emissions and devise different methods that will make it possible. Other countries have made it possible by imposing carbon cess or tax. There is also a need to chalk out carbon mitigation and adaptation plan and formulate an action plan document for Mumbai with specific roles and responsibilities at the individual, corporate and government level," said Dr Rakesh Kumar, head scientist, NEERI.

According to estimates, there will be a need to plant 5,100 million trees for offsetting carbon dioxide in 2051. One tree, according to experts, has the capacity to offset on average of about 10 kg carbon dioxide each year.

Govt, citizens need to share blame, say experts

The biggest problem is that the government does not understand the impact of climate change. In the name of development, largescale "devilopment" is taking place. If we destroy natural resources, how will it be possible for th e city to thrive? Debi Goenka | founder of Conservation Action Trust

Water shortage is a big environmental concern. We take it for granted that there is ample water. Wastage happens at the domestic level more than at the industrial level. It is one of the major natural resources, which is getting wasted Sharad Chaphekar | director, Indian Institute of Environmental Medicine

Both the government and citizens are not focusing on the low hanging fruits. They should realize that the smallest of things we do every day, like minimizing use of fume-yielding vehicles and choosing walking/cycling instead, improving our habits to save energy, can make a big impact on environment Rishi Aggarwal | environmentalist

Traffic and construction are the biggest hazards to noise pollution. We haven't taken any measures to institutionalize steps such as noise mapping. There is no concrete action plan. Also, there is complete lack of awareness on use of sand