Mumbai: India is likely to overtake the US as the second largest emitter of carbon from energy use by 2050, after China amid rising demand for crude oil and coal in the country.
''Together, these two emerging giants are projected to account for around 45 per cent of global carbon emissions from energy by 2050 compared to only around 20 per cent of the global total for the US and EU combined," consulting and research firm PricewaterhouseCoopers said in a report.
The report cited the growing power generation and transport sectors in these countries that would contribute to more carbon emissions than from other sources.
The rise in vehicle population in these two emerging economies would lead to high growth rate in emissions, it stressed.
The scale of the challenge posed by global warming has grown even greater since an earlier report on this topic in 2006, thanks to higher projected economic growth in China and India, the report said.
''The updated 2008 report concludes that the cost of pursuing a 'business as usual' approach would be a more than doubling of global carbon emissions from energy use by 2050, leading to an accelerating rise in atmospheric concentrations of carbon dioxide and a severe risk of adverse climate change effects on future generations,'' PWC said in the report.
With higher growth CO2 (carbon dioxide) in major economies emission is estimated to rise by 55.8 per cent, from around 385 parts per million (ppm) now to around 600ppm by 2050 globally, it said.
''It would be technologically feasible without excessive economic costs' to bring down global emissions by half the current level by 2050,'' the report suggested.
''We estimate that the costs of halving global carbon emissions by 2050 should be no more than around 3 per cent of world GDP. This is broadly equivalent to sacrificing around a year of global GDP growth between now and 2050. In other words, reaching the same level of GDP in 2051 as might otherwise have happened in 2050,'' John Hawksworth, head of macroeconomics at PWC and the main author of the report, said.
''The key requirement now is for governments in all of the major economies, including the US and developing economies like China and India, to send the right economic signals to private sector investors and consumers for delivering the new technologies and changes in behaviour that are required to combat global warming," PWC Climate Change Services head Bharti Gupta Ramola said.
For the advanced G7 economies, this requires a reduction in carbon emissions by around 80 per cent relative to current levels by 2050, whereas for the E7 emerging economies led by China and India, it involves mitigating the growth of emissions up to around 2020 and then aiming for reductions in emissions after that date, he said.
Higher oil and gas prices should help to incentivise the move to greater energy efficiency and use of renewables, the report added, while also highlighting other issues such as the trade-off between increased biofuels production and affordable food.
This scenario requires significantly increased energy efficiency in all sectors of the economy, greater use of renewables and nuclear power, carbon capture and storage, and other low carbon technologies and techniques - as well as reducing deforestation.
Putting a price on carbon emissions through an appropriate combination of global carbon trading and carbon taxes is also critical, it added.