Rabbits don't drive electric cars
Introduction
Learning Objectives
Travel in the Past
Rabbits don't travel very far. They stay in their same local area for most of their life.
Early humans were the same. It's only in recent times with the availability of cheap fossil fuels that humans have been able to travel such great distances in cars, planes, ships and even rockets.
Transport today contributes about 20% of all GHG emissions.
So as a general rule, the less we travel the lower our GHG emissions.
No Electric Cars are Zero Emission
We often hear politicians making claims that electric cars produce zero emissions. The assumption is that because electric cars produce zero emissions we can travel as far as we like.
That’s not true. Lots of emissions are produced when mining materials to be used in electric cars, especially the battery and other electrical components. The battery along weighs 200kg. Emissions are produced at all stages of manufacture and in the transport over sea. These emissions are rarely counted.
There are also emissions during the running of the car because renewable energy sources still produce emissions, just like the electric car. If the electric car is powered using coal power plants then it will still be releasing greenhouse gas emissions into the atmosphere.
Just think, there are 8 billion people on Earth and everyone would like to get around in private cars. It will be impossible if we consider that each new car produces around 15 tonnes of GHG emissions.
Reducing GHG emissions from Transport
It may seem obvious, but there are two things we need to do to reduce the GHG emissions from transport.
- Travel less (stay mostly within your neighbourhood)
- Travel using less energy intensive transport (e.g. walking, biking, public transport, telecommuting)
Travelling Less Distance
- A round trip to Hawaii from Australia (18,000 km) will generate 2.9 tonnes MyClimate. This is about 160 (g.CO2-eq/km)
- A medium sized car will generate 250 (g.CO2-eq/km) of CO2-equivalent emissions per km. If you travel 10km per day, over a year there will be 1 tonne of emissions. Most family cars travel greater distances and average emissions are closer to 3 tonnes per year.
Less Energy Intensive Transport
Here is a sliding scale for Energy intensive transport, starting with the least energy intensive
- cycling
- walking
- telecommuting - more on this later
- public transport
- car pooling
- electric cars and hybrids - still relatively high
- air travel - but often associated with great distances
- private vehicles
The GHG emissions associated with food intake required to fuel a kilometre of walking range between 50 gCO2e/km in the least economically developed countries to 260 gCO2e/km Nature Report
Cycling produces half these emissions.
The lesson here is that all forms of transport generate emissions, even walking and cycling. There is no transport that produces zero emissions.
Embodied Emissions from Transport
When we make something like a bike or car we also release GHG emissions. This is because we need to mine materials from the ground, refine the materials, make and transport the finished item. All these steps produce GHG emissions and are difficult to avoid.
However if we care for a product we can avoid producing these embodied emissions again. Keeping things for longer is generally better than buying something new.
The Target
- We should aim to reduce our transport to the bare essentials.
- A target of 3 tonnes / 15 = 200 kg CO2 emissions per year is compatible with a 1.5 degreeC world. In comparison to the embodied energy in an electric car, this is 75 times less carbon intensive. The 15 fold reduction is derived from reducing emissions from 15 tonnes/person/year to 1 tonne/person/year.
- If we divide the 200 kg by 48 working weeks in the year the result is 4.16 kg CO2 per week.
- If we assume that the car is used 6 days per week the result is 4160 g / 6 = 694 g CO2 per day.
Carbon footprint of travel per kilometre
- The graph below shows the carbon foot print of different modes of travel [1]
- This data is based on UK and European data. Australian emissions will be slightly higher because of the absence of nuclear power.
- Carbon emissions from walking and cycling are not shown.
- The carbon footprint of cycling one kilometre is usually in the range of 16 to 50 grams CO2eq per km depending on how efficiently you cycle and what you eat.
- The carbon footprint for walking will be approximately double the cycling footprint.
- Translated into km distance per day based on a
