David Cameron and Nick Clegg have launched a Carbon Plan setting out the coalition government's policies to meet its long term commitments to cut carbon emissions.
These must, by law, be cut by at least 80% of 1990 levels by 2050. They have already been cut by more than 25%.
The Carbon Plan states that with the policies already in place the economy will significantly exceed the 34% target set for the first 15 years under the Climate Change Act, and would have done so even if the recession had not occurred.
The plan looks to the future in the light of the carbon budgets set by the Committee for Climate Change running from 2008-2012, 2013-2017 and 2018-2022.
However, the Environmental Audit Committee has warned that any loosening of the budget following the 2014 review urged by the Treasury could jeopardise the 2050 goal.
And an independent assessment says that the UK's greenhouse gas emissions are actually increasing by 3.5%; more than double the 1.3% growth in the economy, according to a recent report from PricewaterhouseCoopers' Low Carbon Economy Index.
The Carbon Plan says that in the next decade the focus will be on energy efficiency, utilising the Green Deal, EU ETS, Climate Change Agreements and the CRC Energy Efficiency Scheme, as well as the benefits of the smart grid, which will help to reduce and manage peak and overall demands.
The average emissions of motor vehicles are expected to fall by a third, mostly due to more efficient combustion engines and sustainable biofuels.
Emerging low carbon technologies will be piloted, examined and deployed as they reach commercial levels.
During the 2020s, the successful technologies will move towards mass rollout, and this will include cheaper electric cars. The plan hopes that this will help the UK to "gain a long-term competitive advantage" in these technologies.
In the following decade, after the quick wins have been achieved, then emissions from the “hard to treat sectors, such as industry, shipping and agriculture will have to be tackled", energy secretary Chris Huhne says in his ministerial statement accompanying the plan.
He says that its publication is timed to coincide with the United Nations climate negotiations taking place in Durban, “to show that the UK is walking the walk, demonstrating that even in tough times it can be done".
Huhne is on his way to attend the talks next week.
The UK's 2020 target to reduce emissions by 34% is much less than the EU's 20% below 1990 levels by 2020 (rising to 30% if other nations commit to comparable efforts under a broader climate pact).
"Our national economic interest is to be found in a cost-effective transition to low carbon, to an economy that is more resilient, innovative and efficient,” Huhne added.
The plan envisages that by 2050, emissions from heating and powering buildings will be virtually zero, and the roads will be filled with ultra-low emission vehicles.
In a closed-loop society, waste will be a thing of the past, and materials will either be reused or become an energy source.
However, we will need much more electricity, perhaps as much as twice the amount, to deal with peak demand and power vehicles and provide heating, despite a projected reduction in demand per head of population due to energy efficiency measures by up to 50%.
The government says it does not wish to pick particular technology winners, instead helping academia, industry and the market to work together to do this.
But the plan does outline different possible scenarios: a “higher renewables, more energy efficiency" scenario; “higher carbon capture and storage, more bioenergy" scenario; and a “higher nuclear, less energy efficiency" scenario.
Nuclear power is currently projected to be the cheapest low carbon technology in the future, and the most cost-effective power mix using traditional cost analysis (based on the 'MARKAL' model, which has certain disadvantages) is anticipated to be 33 gigawatts (GW) of nuclear, 45GW of renewables and 29GW of fossil fuels with CCS.
The government says that this would result in energy costs to consumers being reduced by £84/person/year.
This would involve tripling the amount of nuclear power currently installed. But this week, EDF Energy, currently expected to build the UK's first new plant in three decades, at Hinckley, Somerset, said that its schedule was being put backwards due to extra safety checks.
Energy minister Charles Hendry also revealed yesterday that the government wants to build a new plant for processing nuclear waste, four months after a similar plant costing the taxpayer £1.4 billion was closed.
It will convert the UK’s giant stockpile of used plutonium into a form of nuclear fuel.
He said: “converting the plutonium into mixed oxide fuel is the most credible and technologically mature option,” and “any remaining plutonium whose condition is such that it cannot be converted into MOX, will be immobilised and treated as a waste for disposal″.
In the next 10 years decisions have to be taken which will affect the picture 30 years later: switching from coal to gas powered generation and renewable electricity, which will also help reduce exposure to volatile fossil fuel prices.
In the following decade, carbon capture and storage and nuclear power are expected to be deployed alongside more renewables. Around 60 to 80 GW of new capacity will need to be built by 2030.
The main barrier to this is lack of investment. The current electricity prices driven mainly by gas power stations. The reform of the electricity market is partly designed to address this problem.
The Green Investment Bank is expected to be lending money from 2015, when most funding for the construction of Round 3 offshore wind is required.
A calculator, based on the 'MARKAL' model, has been made available on DECC's website which attempts to explain the total costs associated with powering the entire economy, averaged over the four decades up to 2050.
It includes the costs of the infrastructure and technologies required across all sectors (everything from family cars, to gas boilers to power stations), the costs of financing that infrastructure investment over time, and the costs of fuel and maintenance to keep those infrastructure and technologies running.
A revised online 2050 calculator also allows users to compare the cost of their chosen future energy system compared to doing nothing, or to other low carbon pathways.