Introduction

Carbon footprint is a synonym for emissions of carbon dioxide or other greenhouse gases (GHGs) expressed in carbon dioxide equivalents. This has been used as an environmental indicator to understand and quantify the main emission sources and it constitutes as an effective tool for energy and environment management. It helps us to determine the quantity of emission from different carbon emitting sectors, which in turn is useful for quantifying the impact of human activities on the environment and global climate. Carbon dioxide concentration in the atmosphere has been rising alarmingly in the post industrial revolution era and the current level is about 379 ppm (ppm = parts per million) compared to 280 ppm earlier (pre industrialisation). The Planning Commission of the Government of India advocates in the 12th Five-Year Plan of the country for low carbon growth.  The proposed actions will reduce India’s emission intensity from 20% to 25% by 2020 with respect to the emissions in 2005. This includes policy interventions to reduce emission intensity through fuel-efficiency standards, green building codes and energy efficiency certificates. In this context, numerous challenges that are to be addressed include the burgeoning population coupled with urbanisation, industrialisation and provision of infrastructure and transport facilities. This necessitates decentralised mitigation strategies to minimise carbon emissions which require sector wise and region wise inventory of GHG emissions. National  GHG emission inventories based on United Nations Framework Convention on Climate Change (UNFCCC) aid in this regard for evolving mitigation policies and action plans. The national inventories of emission and sequestration provide a general guideline for assessing the mitigation alternatives [1]. Statewise estimates of emission inventories help to understand the major sources and sinks of carbon at regional levels. It also helps to understand the carbon flux and facilitate in the implementation at local levels by sector wise mitigation policies.

Carbon footprint at local level helps in aligning climate policy with local development, sharpening the awareness of municipal stakeholders about the links between local activities and climate change and local benchmarks against a city’s own historical emissions [2]. Environmentally extended input–output analysis (EE-IOA) has long been recognized as a useful top–down technique to attribute pollution or resource use to final demand in a consistent framework [3, 4, 5]. Interest for EE-IOA has increased with the significant increase of interest in consumption-based emission and resource accounting. Consumption-based accounting focussing on GHG has become relevant for policy and decision making. This approach, where all emissions occurring along the chains of production and distribution are allocated to the final consumer of products, is seen as providing several opportunities. Consumption-based accounting  (CBA)  complements the territorial-based approach [6, 7] by including all drivers of GHG emissions associated with consumption.

Consumption based GHG emission inventory varies with income and urbanization. Carbon footprint of twelve metropolitan cities, with inter and intra variability in metropolitan areas and found Delhi has lowest per capita CF of 0.70 metric ton with lowest per capita income of $950 where as Los Angeles and New York both with higher per capita income of $46,040 have CF of 3.69 and 1.94 metric ton respectively due to higher consumption pattern [8]. Urbanization has changed our lifestyle as well as consumption pattern. Carbon footprint analysis of metropolitan America using national database through transportation and residential sectors show that per capita carbon emissions vary substantially as large metropolitan areas offer greater energy and carbon efficiency [9]. Study on housing sectors reveal that wood intensive houses store more embodied carbon compared to normal modern houses [10]. Current Indian population has crossed 1,200 million according to the Directorate of Census Operation, with approximately 28% living in urban areas. This share is predicted to increase to about 40% by 2021 [11]. India and China account for 51% of incremental world primary energy demand in 2006-2030 as per WEO [12]. Urban areas in these countries are the prime energy demand and also GHG emission centres. An inventory of the energy status and carbon emissions of 54 South Asian cities, including 41 cities from India, based on the city energy consumption and related carbon emissions show that major metropolitan /urbanized and industrialized regions have higher GHG emission [1, 13].

The demand for energy has been increasing with urbanisation and burgeoning population. Electricity, fuel wood, kerosene and Liquefied Petroleum Gas (LPG) are used for cooking and lighting in rural and urban areas in India. Estimates indicate that in urban areas, per capita per month consumption of firewood, electricity, kerosene and LPG are 6.65 kg, 22.32 kWh, 0.22 litre and 1.81 kg, respectively. The total installed capacity of electricity generation has increased from 16 GW in 1971 to 174 GW in 2009 [14].

Socio-economic growth coupled with the boost in the infrastructure sector during the post globalisation era has enhanced the growth of cement and steel industries. The production of cement has increased to 181.61 mt in year 2008-09 as against 168.31 mt in year 2007-08. Similarly, the crude steel production shows annual growth of 1.23% [15]. However, these increases in cement and steel production have enhanced carbon emissions surpassing natural sequestration of carbon.

Forest vegetation and soil are major carbon sinks. In 2005, India’s  forest cover was spread in an area of 677,088 km² and it accounted for 20.6% of the total geographical area of the country, whereas, tree cover accounted for 2.8% of India’s geographical area [16, 17]. The greater forest cover is proportional to greater carbon storage because forest soil has the potential to sequester carbon. Also, improvements in agricultural practices would increase the quantity of organic carbon in soil [18].

In this context, decentralised inventory of carbon emission via-a-vis sequestration potential at disaggregated levels would help in implementing carbon capture strategies.  This requires sector wise analysis of sources and sinks at disaggregated levels and region specific mitigation measures depending on the sources. The focus of this work is to develop the state wise carbon balance inventory for India. Electricity generation, transport, industries, domestic energy, agriculture and waste disposal sectors are considered for emission estimates. Forest biomass, forest soil and agricultural soil are considered for carbon sequestration. This is done based on the compilation of data from each sector in all states of India and through the review of the emission and sink experiments carried out in India and India specific IPCC default emission factors [1, 19, 20].