The current discourse surrounding sustainable energy is frequently dominated by “twaddle.” Everyone agrees that transitioning away from fossil fuels is crucial, and individuals are encouraged to “make a difference,” yet many of the actions and proposals suggested simply don’t add up when scrutinized numerically.
This high level of “twaddle emissions” arises because public debate often becomes emotional—concerning wind farms or nuclear power, for example—and people rarely discuss concrete numbers. If numbers are mentioned, they’re often cherry-picked to create an impression, sound impressive, or score points in arguments, rather than genuinely contributing to thoughtful discussion.
This series is fundamentally concerned with cutting through that emotion and concentrating on basic arithmetic, because, as Sir David King FRS noted, basic arithmetic is all it takes to distinguish between viable strategies and “pipedreams.”
The Chasm of Disagreement
The emotional nature of the debate obscures what is essentially a numerical challenge, leading smart people to wildly differing conclusions.
Consider the debate over resource depletion: Caltech physicist David Goodstein predicted an impending energy crisis caused by the end of cheap oil, expecting the crisis to “bite” possibly as soon as 2015 or 2025. He argued that even a miraculous switch to nuclear power immediately would only replace the oil crisis with a uranium depletion crisis within twenty years. Conversely, Bjørn Lomborg, an economist, painted a completely different picture, asserting that “everything is fine,” “everything is getting better,” and “there is plenty of energy,” implying no major energy crisis is looming.
Similar stark polarization exists within UK energy policy debates. During discussions about expanding nuclear power, Michael Meacher, a former environment minister, claimed that cutting greenhouse gases by 60% by 2050 has “no other possible way of doing that except through renewables.” In direct contrast, Sir Bernard Ingham, speaking in favor of nuclear expansion, countered that “anybody who is relying upon renewables to fill the [energy] gap is living in an utter dream world and is, in my view, an enemy of the people.”
Even within the ecological movement, disagreement rages. Jonathan Porritt, chair of the Sustainable Development Commission, asserted that “a non-nuclear strategy could and should be sufficient” to achieve necessary carbon savings and secure energy access up to and beyond 2050. Yet environmentalist James Lovelock wrote that it is “much too late” for sustainable development and that power from nuclear fission is “the only effective medicine we have now,” dismissing onshore wind turbines as “merely… a gesture.”
These passionate arguments often rely on broad adjectives, such as claiming “nuclear is a money pit” or “we have a huge amount of wave and wind.” The flaw in this approach is that knowing something is “huge” is insufficient; one needs to quantify how that specific “huge” resource compares numerically with our existing “huge energy consumption.” The path forward requires numbers, not adjectives.
The Arithmetic of the Energy Challenge
The core task illustrated by the numbers is just how challenging replacing fossil fuel will be, necessitating both new energy technology and aggressive energy conservation measures.
To grasp this challenge, we must systematically quantify both energy consumption and sustainable production, creating a detailed balance sheet. The goal is to compare potential sustainable energy supply (the green stack) against current energy demand (the red stack).
Understanding the Units of Energy
For clear discussion, it’s essential to establish precise terminology, as energy units are frequently confused.
| Concept | Water Analogy | Measurement Units |
|---|---|---|
| Energy | A volume of water (e.g., one litre if thirsty) | Joule (J), Kilowatt-hour (kWh), Megajoule (MJ) |
| Power | A flow rate of water (e.g., litres per minute from a tap) | Watt (W), Kilowatt (kW), Megawatt (MW), Gigawatt (GW), Terawatt (TW) |
The kilowatt-hour (kWh) equals 3.6 million joules (3.6 megajoules). Crucially, power units already incorporate time: one watt is defined as one joule per second, meaning “kilowatt per second” is nonsensical. A 1-kilowatt toaster consumes power at a rate of 1 kW.
To make national consumption and production figures relatable and comparable globally, they are expressed per person. The chosen standard unit for this series is kWh per day per person (abbreviated as kWh/d/p). For reference, 1 kWh/d per person nationally is equivalent to 2.5 GW.
The Motivations: Finite Resources, Security, and Climate
Three main motivations drive contemporary energy discussions:
1. Fossil Fuels as a Finite Resource
The primary concern is that cheap oil, which powers most transport, and cheap gas, used widely for heating, may become depleted within our lifetime. While some dispute the timing, warnings about an oil crisis biting as early as 2015 or 2025 exist. Even if one were to mine non-renewable resources like uranium, the reserves for use in once-through nuclear reactors could face depletion within hundreds of years if global consumption were significantly scaled up. The need to find alternative sources is clear.
2. Security of Supply
Dependence on foreign sources, particularly for oil and gas, introduces political and economic vulnerability. High fuel prices have been deemed a significant risk to European and global growth, leading to calls for increased drilling and petrochemical investment.
3. Climate Change
The foundational fact is that carbon dioxide (CO₂) concentrations are rising. This rise is directly linked to the burning of fossil fuels.
The Historical Reality of Emissions
The period between 1800 and 2000 saw immense change, notably initiated by James Watt patenting his steam engine in 1769. From 1769 to 2006, world annual coal production increased 800-fold and continues to increase today. Coal remains the largest source of CO₂ emissions among fossil fuels.
The fundamental issue is that while natural carbon flows (like absorption by the ocean and atmosphere) were historically balanced, the addition of carbon from burning fossil fuels creates a new flow that is not cancelled out.
This process can be understood using the airport queue analogy: Imagine an airport passport control where 1,000 passengers arrive per hour, and 1,000 officials process them per hour. The queue maintains a modest length. If an extra 50 passengers arrive per hour (a small addition compared to the original flow), but the service rate remains 1,000 per hour, the queue will “slowly but surely” grow. Similarly, though the fossil fuel carbon flow is small compared to massive natural flows, because it is unbalanced, the concentration of CO₂ in the atmosphere accumulates.
Global Disparity and Britain’s Burden
Globally, CO₂ emissions are highly unequal. In the year 2000, Europe’s per-capita greenhouse gas emissions were twice the world average, and North America’s were four times the world average.
Historically, this disparity is even starker. When assessing cumulative CO₂ emissions per capita over the period 1880–2004, Britain ranks second only to the USA. The UK is currently a “fairly typical high-GDP country” compared to nations like Germany, France, and Japan, making it a suitable case study for how an affluent society can achieve sustainable energy.
To avoid catastrophic climate change, trajectories suggest global emissions must fall by 70% or 85% by 2050. If the world adopts “contraction and convergence”—where all countries eventually aim for equal per-capita emissions—Britain must target cuts greater than 85%.
Avoiding Pointless Policies and Fearing the “No”
The effort to achieve these deep cuts requires focusing on solutions that demonstrably “add up.” This involves being critical of ineffective or purely emotional proposals.
For instance, promotional campaigns sometimes encourage small actions, like unplugging a mobile phone charger, which, while saving a few pounds per year, only constitutes a tiny fraction of total energy consumption and should not lead people to believe they have “done their bit.” Similarly, companies like BP celebrate marginal reductions (e.g., changing ship paint) when the focus should be on the core issue—the oil inside the tanker.
Misleading metrics, such as expressing reductions in terms of “equivalent number of cars taken off the road,” are used in advertising to sound impressive but distract from actual numerical impacts.
Even if technically feasible, maximizing the use of Britain’s own renewable resources (the green stack) faces a formidable obstacle: public opposition. People generally endorse renewable energy until proposals become large enough to genuinely make a difference, at which point the sentiment becomes “no.”
Specific objections include:
- Wind farms are “ugly noisy things.” If industrializing the countryside is required, people fear losing tranquil places.
- Forestry “ruins the countryside.”
- Waste incineration raises worries about health risks and traffic.
- Offshore wind is opposed due to concern about “ugly powerlines coming ashore.”
After factoring in these likely objections—the “not in my back yard” or NIMBY effect—the maximum sustainable power Britain might realistically attain from its own renewables is estimated at 18 kWh/d per person. This is extremely challenging when compared to the average British consumption of 125 kWh/d per person.
Therefore, achieving sustainability requires tackling the three biggest categories of consumption—transport, heating, and electricity—by focusing on technologies and policies that deliver big results, rather than relying on the emotional appeal of small, pointless actions.