The target to limit global warming to 2?C this century appears "highly unrealistic" without "unprecedented" cuts in carbon emissions, PricewaterhouseCoopers (PwC) has warned.
The 2?C target was formally agreed at COP-15 in Copenhagen in December 2009. At that time, PwC estimated that a global decarbonization rate of 3.7% per year to 2050 was required to meet that target. Governments have since agreed to launch a review in 2013 to consider strengthening the long-term goal to 1.5?C.
However, according to PwC, the average annual rate of decarbonization between 2000 and 2011 was only 0.8%. If the world continues to decarbonize at that rate, there will be an emission gap of some 12 gigatonnes of carbon dioxide (GtCO2) by 2020, 30 GtCO2 by 2030 and nearly 70 GtCO2 by 2050, as compared with PwC's 2?C scenario.
"Even doubling our current rate of decarbonization would still lead to emissions consistent with 6?C of warming by the end of the century." Leo Johnson, PwC.
In the newly-published fourth edition of its Low Carbon Economy Index, PwC estimates that the required improvement in global carbon intensity to a meet a 2?C warming target has now risen to 5.1% per year up to 2050. However, "Even if it might be achievable in the longer term, it is unrealistic to expect that decarbonization could be stepped up immediately - which means that the reduction required in future years is likely to be far greater than 5.1%." The company warned, "We have passed a critical threshold" and that keeping to the 2?C target "will require unprecedented and sustained reductions over four decades."
"Even doubling our current rate of decarbonization would still lead to emissions consistent with 6?C of warming by the end of the century," said PwC partner for sustainability and climate change Leo Johnson. "To give ourselves a more than 50% chance of avoiding 2?C will require a six-fold improvement in our rate of decarbonization."
PwC noted that major EU economies achieved the highest rates of decarbonization in 2010-11, with the UK, Germany and France all reducing carbon intensity by over 6%. "Both the UK and France witnessed increased generation in low-emissions nuclear power, whereas Germany's exit from nuclear is reflected in its relatively lesser decline in emissions," PwC said. Carbon emissions in the USA decreased by 1.9% in 2011.
In China and India, the reduction in carbon emissions over the last decade "appears to have stalled." PwC suggests that, with their economies set to double by 2020, China and India must stabilize their emissions in order to meet their targets. "The majority of any new energy demand will have to be met from renewable energy or nuclear and not fossil fuel generation," it said.
"Gas may buy some time much needed by the global climate system and help limit emissions growth - displacing coal with gas in power generation roughly halves carbon emissions." However, PwC warns that low gas prices may also reduce the incentive for investment in low-carbon nuclear power and renewable energy - both "critical technologies for low carbon energy generation."
"Large scale renewables and low-carbon technology such as carbon capture and storage (CCS) and nuclear will require significant amounts of political will, finance and time," the company suggests.
PwC concluded that there is a need for "much more ambition and urgency on climate policy, at both the national and international level. Either way, business-as-usual is not an option."