Analysis of report
The World Economic Forum (WEF) has issued a report in which the environmental status of 180 countries has been assessed (Report of World Economic Forum here) WEF has placed India at 177th place. We are celebrating our exalted position among the lowest five countries along with Nepal and Bangladesh.
The main reason for low rank of India is air pollution. The air pollution in turn is attributed to the burning of paddy straw and burning of coal for thermal power plants. The main cause of paddy straw burning is that the Government does not have a scheme to buy the paddy starw at profitable rates from the farmers. For more details please see our full post here.
We would here like to deal with the subject of carbon emissions due to coal burning in power generation. Generally, it is believed that the thermal power causes more pollution, whereas hydropower is comparably clean. But the ground situation is exacty opposite. The carbon emissions generated by hydropower is approximately the same or possibly more than thermal plant.
By washington post (see here)
The carbon emissions from hydropower take place as follows. A big reservoir is built Behind the large dams. The rivers bring Organic material like dead animals, plants, etc. into this reservoir along with the water. These organic materials settle down at the bottom of the reservoir and they start fermenting there. Initially, it absorbs the oxygen available in surrounding the water. The carbon in the organic matter combines with the oxygen in the surrounding water to make carbon dioxide (CO2) which is emitted from the reservoir. After some time the oxygen in the surrounding water becomes merely zero, but the organic matter continues to ferment. Now the carbon presents in organic matter gets combined with hydrogen in the surroundng water and forms Methane Gas(CH4) as shown in the picture below.
This methane gas is nearly 25 times more harmful than carbon dioxide for the environment as detailed in the report below:
In environmental terms, CH4 is a greenhouse gas. It has a Global Warming Potential (GWP) of 25, i.e. 25 times the GWP of CO2, the reference greenhouse gas (the GWP of CO2 = 1) (GWP values from the Intergovernmental Panel on Climate Change (IPCC)'s fourth assessment report published in 2007). Among the greenhouse gases covered by the Kyoto Protocol, CH4 is the second largest contributor to global warming after carbon dioxide (CO2). (for detail study see report here).
A study conducted by International Rivers has found that 2154 grams of carbon dioxide is emitted from large hydropower projects in Brazil in the generation of one unit (kWh) electricity. This is equal to about 900 grams of carbon emissions. In comparison. about 800 grams of carbon is meitted per unit of electricity in the generation of electricity from coal (see report here). Therefore, the more or almost equal carbon is emitted from hydroelectric projects in warm areas like Brazil than thermal electricity. Indeed, International Rivers also says that carbon dioxide emission from major hydro projects in a cold country like Canada was ony 36 gram per kWh. Therefore, the similarity of carbon emissions from hydropower and thermal planst is applicable to hot areas only.
Projects of Himalayan Areas
Many hydropower projects in India are being built in Himalayan regions. A study conducted by the National Environmental Engineering Research Institute, Nagpur (NEERI) found that 2.5 grams of carbon dioxide per square meter per day and 24 mg of methane per square meter per day is being emitted from Tehri lake. (See detailed report of NEERI here).
This works out to approximately 1200 tonnes per day [2.5 gram * 450 sq.km area], which is quite large. It follows that that the hydropower projects in the Himalayas are similar to Brazil and not to Canada.
The low rank of India in the Environment Performance Index, therefore, is not only due to the burning of coal but also due to large hyropower projects. It is unfortunate that the World Economic Forum has remained silent on this.
The World Economic Forum has given importance to air pollution because 16 lakh people are being killed every year in India due to this, mainly due to respiratory diseases. Hydropower projects create another adverse effect on public health. Mosquitos breed in the reservoirs behind and small ponds in the downstream river. These spread infectious diseases such as malaria.
We have received information from Uttarakhand's Health Department that the incidence of malaria in all districts of Uttarakhand except Tehri is declining, which established adverse impact of large dams on health.
The Prime Minister has asked the world's investors to invest in India with great enthusiasm in the World Economic Forum. We hope he will give equal importance to the air pollution. Unfortunately, the Prime Minister is promoting major hydropower projects like Lakhwar Vyasi and Pancheshwar which will only worsen India’s rank in Environment Performance Index.
We must make a basic re-evaluation of hydro-electric projects which have adverse effects on air pollution and public health.