What can be done about climate change?
The scientific evidence is now overwhelming: climate change presents serious global risks. It demands an urgent global response.
What we do in the next 10 or 20 years will have a profound effect on the climate in the second half of this century and in the next.
But what can we do?
The answer is simple: we need to stop burning fossil fuels at such an alarming rate and we need to stop destroying the rain forests.
What levels of greenhouse gas emissions are consistent with stabilising the climate?
The current evidence suggests aiming for stabilisation of the level of concentration of greenhouse somewhere within the range 450 - 550ppm CO2-equivalent. (See Category II/ III in the IPCC table of model predictions).
- To stabilise at 450ppm CO2-equivalent, without overshooting, global emissions would need to peak in the next 10 years and then fall at more than 5% per year, reaching 70% below current levels by 2050.
- Stabilisation at 450ppm CO2-equivalent is already almost out of reach, given that we are likely to reach this level within ten years and that there are real difficulties of making the sharp reductions required with current and foreseeable technologies.
- Stabilising at or below 550ppm CO2-equivalent will require global emissions to peak in the next 10 - 20 years, and then fall at a rate of at least 1 - 3% per year.
- By 2050, global emissions need to be around 25% below current levels.
- Weak action in the next 10-20 years will put stabilisation even at 550ppm CO2-equivalent beyond reach - and this level is already associated with significant risks.
- Remember these cuts will have to be made in the context of a world economy in 2050 that may be 3 - 4 times larger than today - so emissions per unit of GDP would need to be just one quarter of current levels by 2050.
Putting a price on carbon; the polluter pays
Almost every aspect of economic activity results in greenhouse gas emissions. The fight against climate change requires a fundamental change to the basis of our fossil fuelled economies.
The most effective way to motivate such fundamental change is to ensure that the true environmental cost of carbon is reflected in the cost of fuel, electricity and food.
This can be achieved through taxation, regulation and through the 'shadow price of carbon', used by the government to evaluate investment decisions.
The carbon price is an amount payable per tonne of carbon dioxide released into the atmosphere:
- Carbon prices around US$20-50 /tCO2 eq are felt to be sufficient to drive large scale fuel-switching and make both CCS (carbon capture and storage) and low-carbon power sources economic as technologies mature.
- Models suggest that a predictable and ongoing gradual increase in the carbon price that would reach 20-50 $UStCO2-eq by 2020-2030 corresponds with Category III stabilization (550 ppm CO2-eq). For stabilization at levels between 450-550 ppm CO2-eq, carbon prices of up to 100US$t CO2-eq need to be reached around 2030. To put this in perspective the average UK household emits approximately 9 tonnes of carbon dioxide per year (excluding emissions from flights). At a carbon price of £25 per tonne, average fuel and energy bills will rise by £225 per year. At a carbon price of £50 per tonne, average fuel and energy bills will rise by £450 per year. A flight to Australia and back emits over 10 tonnes of carbon per passenger when the effects of radiative forcing are taken into account. At a carbon price of £50 per year, the price of the flight would rise by £500.
The Shadow Price for Carbon in the UK
- The "shadow price for carbon", representing the cost to society of the environmental damage, has already been agreed for every year up to 2050 by UK government economists. It will be set at £25.50 a carbon tonne for 2007, rising annually to £59.60 a tonne by 2050.
- It will be used to evaluate investment strategies. So for example if a new power station will cost £1bn to build, but is expected to add £200m of carbon emissions, it will be assumed that the true cost of the power station is £1.2bn, even though its cash price is £1bn.
Caps on emissions; emissions trading
Kyoto's clean development mechanism caps emissions by rich countries, forcing them to buy permits from poor countries to emit greenhouse gases. The emissions trading program of the European Union is the hub of the global market; the value of EU carbon emissions trading reached $50bn in 2007.
Cutting emissions from energy generation
It is estimated that 60-80% of reductions in emissions will need to come from energy generation, by saving energy and by using carbon-free technology (renewable, nuclear and carbon capture and storage).
Future energy infrastructure investment decisions (expected to total over US$20 trillion between 2007 and 2030) will have long term impacts on greenhouse gas emissions. A wide range of energy-supply mitigation options are available:
- Fuel switching and plant efficiency
- Solar PV and concentrated solar power
- Coal in conjunction with carbon capture and storage (burying carbon dioxide emissions underground)
- Gas in conjunction with carbon capture and storage (burying carbon dioxide emissions underground)
Cutting transport emissions
In 2004 transport energy amounted to 26% of world energy use and accounted for 13% of GHG emissions.
74% of emissions come from road use. Measures to mitigate emissions from road traffic include:
- Increased use of public transport. If the share of buses in passenger transport were to increase by 5-10% then CO2 emissions would fall by 4-9%.
- More than 30% of the trips made by cars in Europe are for less than 2 miles and 50% for less than 3 miles. Walking or cycling will cut emissions and improve air quality, reduce congestion and improve road safety.
- Taxes on vehicle use and fuels, as well as road and parking pricing policies are important determinants of vehicle energy use and greenhouse gas emissions.
- Cleaner directed-injection turbocharged diesels (TDI), hybrid vehicles and electric vehicles.
- Reduced aerodynamic drag, reduced rolling resistance, reduced engine friction and pumping losses. There is the potential to double the fuel economy of 'new' light-duty vehicles by 2030, thereby roughly halving carbon emissions per vehicle mile travelled.
- Biofuels have the potential to replace a substantial part, but not all, petroleum use by transport.
Small is beautiful
A critical threat to the potential for future reduction of CO2 emissions from use of fuel economy technologies is that they can be used to increase vehicle power and size rather than to improve the overall fuel economy and reduce carbon emissions. The preference of the market for power and size has consumed much of the potential for greenhouse gas mitigation reduction achieved over the past two decades.
- In aviation, technology developments might offer a 20% improvement in fuel efficiency over 1997 levels by 2015, with 40-50% improvement likely by 2050. As civil aviation continues to grow at around 5% each year, such improvements are unlikely to keep carbon emissions from global air travel from increasing.
- The scale of airport expansion threatens the integrity of the UK's whole climate change strategy. Aviation emissions account for at least 9% of UK greenhouse effect. Over a single journey of 1,500km an aircraft emits twice as much greenhouse gas per passenger kilometre as a high speed train. Over a 500km trip, aircraft emit six times more greenhouse gas than high speed trains, and 12 times more than a coach.
Cutting emissions from buildings
- In the UK emissions from homes are responsible for an estimated 27% of the UK's total carbon emissions. Occupant behaviour and choice and use of technologies are major determinants of energy use in buildings.
- A report by the Energy Saving Trust predicts that by 2010 the UK could waste up to £11 billion annually and emit around 43 million tonnes of carbon dioxide through wasted energy, such as leaving lights on and appliances on standby.
- CO2 reductions of between 20-30% in building related emissions could be achieved by adopting proven simple measures:
Measures to reduce energy consumption
- Insulation and double glazing
- Efficient lights (low energy lights, compact fluorescent lamps)
- Efficient appliances.
- Switching off appliances rather than switching them to standby (standby power consumption accounts for 2.25% of electricity production).
- Energy management systems.
Switching to low carbon fuels, including a higher share of renewable energy from the grid or generated on site:
- Solar hot water and electricity.
- Heat pumps.
- Wind turbines.
- Use electricity generated by carbon free technology.
- Annual investment by the private and public sector of £0.75 billion per year over 40 years would reduce our building-related CO2 emissions by 33% in 2050. That annual expenditure is less than 1% of what we currently spend on construction each year.
Cutting emissions from agriculture
90% of mitigation potential arises from sink enhancement (soil C sequestration) and about 10% from emission reduction. Policies link in with sustainable development - maintaining soil carbon, efficient use of fertilisers.
Cutting emissions from deforestation
Land use and deforestation account for approximately 20% of global greenhouse gas emissions. Action to prevent further deforestation is needed urgently. Most proposals involve countries claiming credits for valuable forests, which they could then trade.
The poorest developing countries will be hit earliest and hardest by climate change, even though they have contributed little to causing the problem. Their low incomes make it difficult to finance adaptation.
The international community has an obligation to support them in adapting to climate change, and in switching to a low carbon economy.
Developing countries are already taking significant action to decouple their economic growth from the growth in greenhouse gas emissions. For example, China has adopted very ambitious domestic goals to reduce energy used for each unit of GDP by 20% from 2006-2010 and to promote the use of renewable energy. India has created an Integrated Energy Policy for the same period that includes measures to expand access to cleaner energy for poor people and to increase energy efficiency.
The Clean Development Mechanism, created by the Kyoto Protocol, is currently the main formal channel for supporting low-carbon investment in developing countries. It allows both governments and the private sector to invest in projects that reduce emissions in fast-growing emerging economies.
In future, a transformation in the scale of, and institutions for, international carbon finance flows will be required to support cost-effective emissions reductions. The incremental costs of low-carbon investments in developing countries are likely to be at least $20-30 billion per year.