Tackling Climate Change - the role of the engineer

Edited version of a paper given by Dr Stuart Parkinson, SGR, at Women's Engineering Society annual conference, 'Proper Practice: Professionalism and Ethics in Engineering and Science' 12th Sept, 2003 at the Earth Centre, Doncaster, UK.

For a more detailed discussion of many of these issues, see the SGR briefings 'Career choice and climate change' and 'Cleaner technology: a positive choice'. (Updated February 6th 2005)


Global climate change is one of the greatest environmental threats facing the world. Human activities such as the burning of fossil fuels and deforestation over the past 150 years have led to the emissions of massive amounts of greenhouse gases (eg carbon dioxide and methane). These gases are increasing the amount of heat trapped in the atmosphere leading to changes in climate faster than at any time since the transition from the last ice age 10,000 years ago [1]. The consequences will be grave: large rises in sea level causing widespread coastal flooding; more severe weather (droughts in some areas, storms in others); and major threats to agriculture and natural ecosystems. Those affected most will be those already vulnerable today: people in poorer countries and endangered wildlife.

The choices that society makes on the use of engineering today and in the near future will be instrumental in determining whether we successfully tackle the problem or not. In this paper I briefly outline some of the main technical options for dealing with climate change, and highlight the ethical dilemmas that surround these options.

Reducing Greenhouse Gases

Because so many human activities result in emissions of greenhouse gases (GHGs), there is a very wide range of possible ways of reducing these emissions. Here I focus on three areas of particular importance to engineering:

  • Changes in energy production
  • Improvements in energy-efficiency by technical means
  • Reducing GHG emissions by social means

Changes in energy production

Energy production can be changed in several ways to reduce emissions. For a start we can switch away from coal and oil to gas, as gas emits only half the CO2 of coal and two-thirds the CO2 of oil per Joule of energy used. A further way is to expand the use of Combined Heat and Power (CHP or cogeneration) plants. Such plants use the waste heat from electricity production to provide space heating or hot water for local buildings. Whereas conventional plants producing electricity work at efficiencies of about 35% to 45%, CHP plants work at efficiencies of up to 85%.

Of course, the most effective change in the production of energy would be to use energy sources which do not emit any GHGs at all during operation. Renewable energy sources, such as solar, wind, hydro, biomass and geothermal, obviously fit into this category. Of these, wind energy (both on-shore and off-shore) has the highest potential in the UK. Onshore wind can already produce electricity at a competitive price, while the price of offshore wind is falling fast. The UK Government has set a target of 20% of electricity generation to be from renewable energy sources by 2020. Studies shows that the potential is much higher than this [2].

One problem, however, with some renewable energy sources is that they are intermittent: the sun does not shine all the time, and the wind does not blow all the time. Hence an important consideration is the required level of 'back-up' power plants (which can be other renewable sources, eg biomass, or not) to prevent power shortages. Power storage is also a way of dealing with the intermittency problem - however, this is still at an early stage of development. A growing number of energy producers envisage an eventual switch to the 'hydrogen economy'. This would be where energy sources (mainly renewable) are used to produce hydrogen from water by electrolysis, which is then stored or transported as required, to be used to deliver electricity from the recombination of the hydrogen and oxygen in a fuel cell. This technology is still at an early stage of development.

Nuclear power is another energy source which produces no GHG emissions during operation (although emissions from uranium mining and plant construction are not negligible). Currently nuclear power supplies 22% of the UK's electricity and 16% of world electricity [3]. It has the advantage over wind and solar energy in that it is not an intermittent supply, but of course it is highly controversial as I shall discuss later.

A further option for dealing with the CO2 emissions of energy plants is CO2 capture and storage. This is where CO2 is removed from the exhaust gases of a fossil fuel plant and piped into underground geological formations, eg former oil reservoirs. Again, the controversies surrounding this technology will be discussed later.

Improvements in energy-efficiency by technical means

The potential for technical change to lead to energy efficiency improvements as a way of reducing GHG emissions is very high. For example, most buildings in the UK are not well insulated due to (up until recently) low energy efficiency standards being followed in the building industry. Since most buildings are heated using fossil fuels, either directly or indirectly, a large amount of GHG emissions are needlessly produced. Large-scale deployment of building insulation will thus yield significant savings. Further, the recent improvements in the energy efficiency standards governing household appliances is beginning to have an effect.

One of the largest sources of GHG emissions in the UK is from motor vehicles. The recent introduction of the first 'hybrid' cars, which use a combined petrol-driven motor with an electric motor, can reduce fuel consumption by up to 50%. The promise of using fuel cells (see above) to drive motor vehicles has the potential to reduce GHG emissions further.

Reducing GHG emissions by social means

It is also important to consider social changes which could reduce GHG emissions. For example, if more people were to switch transport mode, from cars to public transport or cycling they could make very large savings in their personal energy consumption and hence reduce emissions. Of course, the ability of people to make such changes depends on many factors, such as how far they live from work. But if such changes encourage people to live closer to work, they could reduce their emissions further. Indeed basing more of our economy on local activity, eg buying locally-produced food or other goods and services, could reduce GHG emissions quite substantially.

Ethical dilemmas for engineers

There are four main ethical questions I will tackle in this section:

  1. Will nuclear power cause more problems than it solves?
  2. Is CO2 capture & storage an acceptable option?
  3. Are improvements in technical efficiency just undermined by more consumption?
  4. Will reducing GHG emissions conflict with international development?

Will nuclear power cause more problems than it solves?

The issue of whether to build new nuclear power stations as a way of tackling climate change is one of the most controversial areas. There are four basic problems with nuclear power: connection with nuclear weapons; disposal of radioactive waste; safety of nuclear installations; and cost.

Nuclear power plants use highly enriched uranium (HEU) as fuel. HEU (at higher enrichment levels) can be used to produce nuclear weapons. Following use in the reactor, the spent fuel includes significant amounts of a variety of isotopes of plutonium. While the plutonium from a civil nuclear reactor is not classified as 'weapons grade' (because it has a high fraction of the higher isotopes of plutonium), reprocessing of the fuel converts it to a form which can more easily be weaponised [4]. The current tensions over North Korea and Iran's nuclear plants, not to mention the possible theft from, eg, badly secured stores of Russian HEU demonstrate that these issues still have major international security implications.


Radioactive waste is also of serious concern. A typical 1 giga-watt nuclear power plant produces 32 tonnes of high level waste (including uranium and plutonium), and approximately 300 m3 of low and intermediate level waste each year [5]. The high level waste is of particular concern because of its very hazardous nature. Discussions still rage about its long-term disposal.

Nuclear installations, especially temporary waste storage and processing sites, are also potential terrorist targets. Scientists for Global Responsibility has estimated that the effects of a September 11th-type plane crash on Sellafield waste facilities would be catastrophic [6].

The economics of nuclear are also not promising. Despite nearly 50 years since the first civil nuclear power station was opened, no nuclear power plant has been built anywhere in the world without government assistance, either in construction costs, operation costs, insurance cover or decommissioning costs. In the UK, both British Energy, which operates Britain's newest nuclear power plants, and British Nuclear Fuels (BNFL), which manages the country's nuclear waste, are in severe financial difficulties. BNFL has liabilities resulting from nuclear waste amounting to a massive £41 billion [7].

Is CO2 capture & storage an acceptable option?

CO2 capture and storage (CCS) raises a number of ethical issues. The first is whether the CO2 injected into the ground will leak out. Current research indicates that the CO2 will remain, but it is still a technology in the early stages of development. Further concerns include the way in which it will support the continued use of fossil fuels. The extraction and transport of fossil fuels have significant non-climate environmental and social impacts, eg oil tanker spills and damage to ecosystems during oil extraction. Perhaps the strongest concern is that it will continue to exacerbate geo-political problems, eg in the Middle East. Related to this is the concern that R&D in this area will divert finance away from renewable energy.

Are improvements in technical efficiency just undermined by more consumption?

When energy efficiency is improved it obviously leads to a drop in the amount of energy that can be sold by suppliers. To compensate (which is the same for any business whose sales fall), the suppliers try to lower the price so that people are encouraged to consume more. Unfortunately, such a response can undermine the original energy savings. The simplest way around this is for energy prices to be increased by the use of taxes. The particular taxation method of most relevance to climate change is carbon taxes, whereby the tax is determined by the emissions of CO2 per Joule of energy. Unfortunately, many large businesses involved in energy generation and use oppose such taxes because of the potential cost to their business. However some businesses have more progressive environmental policies and support such taxes.

Will reducing GHG emissions conflict with international development?

A criticism which has been levelled by some of the developing world is that, if they are forced to reduce GHG emissions, this may increase the costs of energy and hence undermine their efforts to tackle poverty. Hence it is crucial that the richer industrial nations assist in the transition to cleaner energy generation and use. One aspect of particular benefit to poorer communities is simpler 'intermediate' technologies. These technologies, which include some renewable energy technologies like small-scale hydro and wind, tend to be easier to maintain and cheaper.

An ethical agenda for engineers?

It is very difficult to define exactly what an ethical approach to tackling climate change is. Rather than make pronouncements that any particular technology or approach is ethical or not ethical, I make a series of recommendations of which areas deserve the most attention from engineers.

  • Given that there are options for tackling climate change which have clear benefits, working in these areas should be a priority. These options are:
  • renewable energy technologies because they produce zero GHG emissions during operation;
  • power storage technologies, including hydrogen technologies, which can assist in the deployment of intermittent renewable energy sources;
  • large technical changes in efficiency, eg CHP or fuel cells;
  • technologies that support social change, eg buses/bikes rather than planes/cars;
  • intermediate renewable and energy efficiency technologies that will be of particular value to communities in poorer countries.
  • Seek employment with organisations with strong environmental and social policies, including supporting eco-taxes.

(web links correct as of September 2003)

  1. IPCC (2001) Climate Change 2001: The Scientific Basis. Second Assessment Report. Working Group I of the Intergovernmental Panel on Climate Change. Summary for Policymakers. http://www.ipcc.ch/
  2. Eg p34-35 of Boyle G. (1996) Renewable Energy: Power for a sustainable future. Oxford University Press.
  3. International Atomic Energy Agency (2003) Country nuclear power profiles. http://www-pub.iaea.org/MTCD/publications/PDF/cnpp2002/index.htm
  4. p70-83 of Barnaby F. (2003) How to make a nuclear bomb and other weapons of mass destruction. Granta.
  5. p106 of Grimston M.C. and Beck P. (2002) Double or Quits?: The global future of civil nuclear energy. Royal Institute of International Affairs/ Earthscan.
  6. Scientists for Global Responsibility (2002) Could terrorists turn the UK into a nuclear wasteland? p1 & 8 of SGR newsletter, 24. March.
  7. Brown P. (2003) Sellafield shutdown ends the nuclear dream. The Guardian. 26th August. http://www.guardian.co.uk/nuclear/article/0,2763,1029361,00.html