Renewable energy and climate change
Abstract
The energy sector is the major contributor to human-made greenhouse gas emissions. Can wind, wave and solar energy save us from catastrophe?Godfrey Bevan explores the issues of renewable energy and efficiency – and finds huge potential, but a terrifying lack of time.
It has been recognised1 that greenhouse gas (GHG) emissions, generated by humankind, are bringing about potentially catastrophic climate change. An unprecedented rapid rise in global average temperature is one of these changes. The major contributor to human-made GHG emissions is fossil fuel consumption. Government, industry and the public generally are all concerned; action is being taken on two major fronts: to reduce consumption and to introduce new, less carbon-intensive, renewable energy sources. However, with economic development and a growing population, both energy consumption and GHG emissions are still growing, and they are projected to continue to grow unless much more intensive mitigation programmes are introduced very rapidly.
Renewable energy sources could supply all our needs and more. But international commitments lag far behind necessary actions
Energy demand
Energy consumption has grown exponentially with population and economic development since the industrial revolution. Figure 1 illustrates this, and shows also how consumption per person varies widely with the level of regional economic development.
Huge and successful efforts have been made internationally to improve the efficiency with which we use energy. Technological development and government stimulation programmes have achieved results, and these are illustrated in Figure 2. In 2010 we were using around 23% less energy per unit of GDP than in 1980. The efficiency improvements are forecast to continue through increasing use of improved technologies in industrial, buildings and transport markets.
These have not been trivial achievements and have taken effort, ingenuity and investment. Yet despite this very significant improvement in energy efficiency, world energy demand is still forecast to grow rapidly into the foreseeable future. The International Energy Agency (IEA), among the most authoritative of the many bodies examining possible scenarios for the future, projects future demand against three sets of assumptions:
- the “current policies” scenario – governments continue to implement current policies;
- the “new policies” scenario – governments implement the new policy commitments that have already been entered into but not yet implemented;
- the “450” scenario – governments implement vigorous policies to limit global temperature rise to 2°C by stabilising GHG emissions to 450 parts per million CO2 equivalent.
Energy demand continues to grow under each of these three scenarios, as illustrated in Figure 3. This has grave consequences for GHG emissions and consequent global temperature rise, even under the most favourable “450” scenario.
What contribution can renewables supply?
To make these scenarios happen, the mix of energy sources will have to change. The three IEA scenarios demand differing contributions from renewables. The progressive growth of their contribution under each scenario is illustrated in Figure 4.
In all of the scenarios fossil fuels continue to dominate, despite their higher carbon contributions. Under “current policies”, renewables and nuclear meet only 21% of supply by 2035. Under the “new policies” scenario the figure is 26%; under “450” it is 38%. For comparison, in 2008 the figure was 19%.
Energy and climate change policy – too little, too late
Governments have recognised and reacted to the increasingly intractable problem of growing demand and GHG emissions since the first oil crisis in 1973. Actions gradually increased in intensity until the formation in 1988 of the Intergovernmental Panel on Climate Change under the auspices of the United Nations. Negotiations have produced a series of partial and limited international agreements, which are summarised in the box on page 11.
Yet despite all these agreements, and despite recognising the seriousness and urgency of the issue, governments have yet to agree and implement programmes on anything like the volume or timescale required even to limit global average temperature rise to 2°C. The IEA2 projected in 2011 that, by 2015, 90% and, by 2017, 100% of the permissible emissions from energy will have been reached to achieve the 2°C limit if we do not change course. The Durban Agreement of December 2011 (see box) aspired to reach a legal agreement by 2015, with actions in place by 2020; it will therefore be too late if the projections are correct.
Consequences of Climate Change
We can consider the consequences of climate change as projected by the IPCC and use them to consider how adequate negotiations such as Durban have been. The 2007 IPCC Assessment Report1 summarised economic and social consequences of climate change. The estimated impacts from increasing average global temperature on water, ecosystems, food, coasts and health are displayed in Figure 5. As can be seen, in all five of these areas the consequences are very serious indeed. The projected temperature rises associated with the “new policies” and “450” scenarios are also shown in the figure.
The goal permitting increases of up to 2°C risks very serious consequences to health, water and food supplies for hundreds of millions of people, as well as the increased damage from storms and floods which we are already beginning to experience. However, the consequences of rises of 3–4°C which are projected for the IEA “new policies” scenario are potentially economically and socially catastrophic for billions of people. Yet this is the scenario which is consistent with the programme commitments already undertaken by the leading countries but not yet implemented – it is the scenario that we are actually facing if governments fulfil their current promises. (If they do not fulfil those promises the outlook is still more catastrophic.) Even this is not the worst: much more recent research measuring, for example, rate of loss of ice fields in the Arctic and Antarctic, and glaciers worldwide, is suggesting that the original estimates were conservative and that climate change is impacting more rapidly than predicted. The world needs to accelerate its response very significantly if even the more draconian risks of climate change are to be avoided. The energy sector needs to play the major role in the changes requiring to be brought about.
International agreements on climate change
- The UN Kyoto Protocol (1997) – 37 countries committed to reducing GHG, by the insufficiently ambitious target of 5.2% from 1990 levels by 2012, with 191 countries agreeing to implement “general” measures. In practice, most countries failed to meet their contributions to the target and GHG emissions have continued to grow rapidly.
- The UN Copenhagen Accord (2009) – all major participating countries agreed a non-binding objective of limiting the increase in global average temperature to 2°C above pre-industrial levels, which required industrialised countries to set emission targets for 2020. Limited action resulted and negotiations continued.
- The G8 Summit (2009) – called to share with all countries the goal of cutting global GHG emissions by 50%, but commitments subsequently announced by some individual countries even if they were fully implemented would not be sufficient to achieve the 2°C limit goal.
- The G20 Leaders’ Meeting (2009) – undertook commitments, over the medium term, to phase out subsidies that encourage wasteful consumption.
- The UN Cancún Agreement (2011) – acknowledged the need to restrict the global temperature rise to 2°C, with many countries announcing non-binding measures, but which again would be insufficient even if implemented to achieve the target.
- The UN Durban Agreement (December 2011) – recognised the need to raise the collective level of ambition to reduce GHG emissions to keep the average global temperature rise below 2°C; decided to adopt a universal legal agreement on climate change not later than 2015, with actions to come into force by 2020; and 38 industrialised countries agreed a second period of the Kyoto Protocol, but Canada withdrew from the Agreement.
Energy resources, markets and prices
There is already large-scale movement towards more sustainable use of energy. There is huge potential to go further, but this implies substantial changes of attitude by the institutions in the energy sector, most notably by governments, by energy supply companies and by energy customers – by and large, ourselves.
The GHG emissions of different energy sources vary widely. Coal and wind, for example, differ by almost two orders of magnitude. Table 1 gives the comparisons. It is evident that there is huge scope to reduce emissions if it were possible to move from fossil fuels to low carbon sources.
There remains the issue of the availability of energy resource and technologies and their comparative economics. Table 2 provides a much simplified summary of energy resource availability and the estimated lifetime at current rates of exploitation together with the state of commercial development.
Conventional fossil fuel resources are relatively limited, are unevenly distributed geographically and are likely to continue to rise erratically in price. Non-conventional fossil fuels, such as shale oil and gas, are much more plentifully available, more evenly distributed geographically and beginning to be exploited commercially, most notably in the United States, though they are more difficult and expensive to obtain. Technologies to capture and sequester the CO2 resulting from fossil fuels are expensive, uncertain and only at the initial stages of commercial development. It seems unlikely that that they could be applied on the very large scale necessary to permit continuing use of fossil fuels into the longer term. Nuclear technologies are at different stages of development. Only fission reactors are commercially exploited but their fuel source is uranium, and uranium supplies are relatively limited and likely to become a constraint if nuclear programmes are much expanded. But renewables could, in theory, supply all our energy. The technical potential for renewables is very much more than any likely worldwide demand for energy might be.
But the renewable sources are not available instantly, to be turned on like a tap. Different technologies are at varying stages of development, from research and development, through demonstration, deployment on a large scale with financial support, to commercial viability at market prices. Traditional biomass (wood), hydro-electricity and wind are currently the largest contributors, with wind growing very rapidly. Solar thermal energy for heating water is already competitive in sunny regions and the cost of solar photovoltaics is close to being competitive with the retail price of electricity in parts of the world where electricity is expensive, such as Japan. In contrast to fossil fuels, the costs of renewables are falling as the technologies mature and move to large-scale exploitation. The costs of the most mature technologies are already beginning to fall below that of fossil fuels in particular circumstances. Renewables are not only the most climate-friendly; they will become the most cost-effective option as the price of fossil fuels inevitably continues to escalate in the future.
| Energy source | CO2 emissions from heat and electricity conversion gCO2/kWh IEA CO2 Emissions Highlights 2010 | Life cycle CO2 emissions from UK electricity generation gCO2/kWh IEA REWP Environmental Implications of Renewables 1996 |
|---|---|---|
| Oil | 640 (crude) | 817 |
| Gas | (natural) 370 | 429 |
| Coal | 840 (anthracite) | 955 |
| Nuclear | 3–30 (various sources) | |
| Renewables | ||
| Energy crops | 30–33 | |
| Hydro | 9 | |
| Photovoltaics | 98–167 | |
| Solar thermal | 61 | |
| Wind | 7–9 |
| Energy resource | Scale of resource | Years of production of proven recoverable reserves* |
|---|---|---|
| Oil | Limited and rising production costs | 41 |
| Unconventional oil | Extensive but expensive | – |
| Gas | Limited | 61 |
| Unconventional gas | Very extensive and widespread | – |
| Coal | Extensive | 128 |
| Traditional biomass | Limited and depleting rapidly | |
| Nuclear | ||
| Fission uranium | Limited | 70–80 |
| Fission thorium | Extensive but experimental | |
| Fast breeder | Unlimited? but experimental | |
| Fusion | Unlimited? but experimental | |
| Renewables | Unlimited? but still under development |
- *Estimates extracted from World Energy Council and World Nuclear Association reports are for years of production at current rates of extraction
One of the key issues with the economics of energy is that supply operates in a variety of markets. They range from “command” economies, through nationalised industries with rates of return determined by government rather than the market, to pure commercial free markets. Regulation of energy prices is very common. Energy supply is both taxed and subsidised in a variety of ways around the world; hence simple market economics do not apply generally.
Bodies such as the IEA attempt to remove the impact of taxes and identify the subsidies involved in their analysis and projections. Fossil fuels remain far the most heavily subsided currently, according to IEA statistics3. I am not aware of equivalent published data for the nuclear industry, which has certainly been heavily subsidised throughout its history either through price support, lower rates of return demanded in the nationalised sector, or underpinning through guarantees and decommissioning and waste storage costs being met by governments. Subsidies for renewables are expected to grow during their development phase; governments have agreed through the United Nations negotiations to reduce subsidies in the medium term.
The developing world
In rural areas in developing countries there are 1–2 billion people without electricity supply, with availability of traditional sources of biomass such as wood and dung for cooking declining, and unable to afford the ever increasing cost of kerosene. Is this politically or socially acceptable? These people are unlikely ever to be connected to “grids”, and localised supply from small renewable energy systems probably offers the only solution. Initial development is beginning to taking place, often through local entrepreneurs and charitable assistance, but the scale of the problem remains immense.
What is the need and scope for future action?
The world is currently embarked upon an unsustainable course, environmentally, economically and socially. Despite 40 years of awareness since the 1973 oil price shock, and despite detailed negotiations on climate change over more than 20 years, according to the best of government aspirations we are heading for a global average temperature rise of 2°C, with severe consequences for hundreds of millions of people. In practice, it is probably already too late to meet those government aspirations. In reality, we are more likely to be heading for a minimum temperature rise around 3–4°C on the basis of actual current commitments. The consequences, for billions of people, are potentially catastrophic.
There is huge scope to increase energy efficiency and move to low-carbon sources. This would lead us back to the necessary path of reducing GHG emissions to a level that is sustainable in the longer term. It would require a much more rapid shift away from continuing investment in fossil fuels than is currently envisaged. The developed world would need to move away from fossil fuels and the developing world would need to avoid following the developed world down the fossil fuel route. Nuclear may be a partial option in the electricity market, but the full costs of nuclear – including decommissioning, waste storage and insurance of liabilities – have yet to be properly acknowledged. The public acceptability of nuclear is also in doubt and new technologies such as thorium-fuelled breeder or fusion reactors would need to be developed to permit a contribution on the scale required in the longer term. A much faster development and deployment of renewables is likely to be the most cost-effective and lowest-risk option, alongside continuing and more extensive application of energy-efficient improvements.
In practice, it seems unlikely that this is going to happen. The “dash for gas” is likely to intensify, with widespread exploitation of unconventional gas sources, since there is a huge resource and the oil and gas companies are set up to pursue it. While this is better than expanding use of coal, the GHG emissions consequences of using even a tiny fraction of the resource are unthinkable. The world needs a change of direction in its energy policies now. It may already be too late.
