Greenhouse Emissions

Discussion

Greenhouse gas emissions, accumulating in the atmosphere, are causing global warming. We can reduce emissions by phasing out fossil fuels, but this will require economic restructuring to avoid disruption.

In 2004 around 49 Gt of greenhouse gas per year were being emitted as a result of global economic activity, up from 28.7 Gt in 1970. (IPCC)

Greenhouse Emissions and Global Warming

What's wrong with greenhouse gas emissions?

Greenhouse gases such as carbon dioxide, methane, and nitrous oxide - emitted by fossil fuel consumption, cement production, land clearing, agriculture, and other economic activities - are accumulating in the atmosphere. This in turn is causing global warming which threatens to disrupt natural habitats and human settlements this century and beyond.

An adequate response to global warming will include reducing greenhouse gas emissions, and so stopping and even reversing greenhouse accumulation in the atmosphere.

The cost of reducing emissions now is likely to be much less than the cost of adapting to the higher global temperatures that unabated emissions would bring.

How to reduce greenhouse gas emissions

The challenge is to develop a global economic system which provides a good quality of life for all people without the high emission levels currently generated.

Greenhouse gas emissions could be reduced very quickly by prohibiting the combustion of fossil fuels. However, fossil fuels are the basis for modern industrial economies, so prohibiting their use overnight would cause widespread economic disruption, which would increased material deprivation.

We need phase out fossil fuels gradually to give us time to restructure our economies. The faster we can restructure, the more quickly we can phase out fossil fuels and hence reduce emissions.

If we restructure global and regional economies appropriately, we may be able to extend material prosperity to all regions and populations, as well as reducing emissions.

This means designing or otherwise creating economies that can deliver prosperity at the relatively low per capita greenhouse emission levels of around 2 t CO2e per year - the level we will need in 2050 if we are to stop greenhouse accumulation and accomodate an expected world population of 9 billion.

Current per capita emissions in industrialised countries are typically 10 to 20 t CO2e per year. Getting down to 2t would be a significant change.

Carbon Dioxide Emissions

How to stabilising atmospheric CO2

Atmospheric CO2 can be stabilised by reducing the rate of CO2 emission from economic activity until it is in balance with the capacity of the oceans, vegetation and other carbon sinks to take up that CO2. That would require reducing CO2 emissions to 50% or more below the current rate.

On current economic trends, CO2 emissions are likely to increase. Current economic trends involve increased demand for electricity, and this demand is being satisfied by commissioning more coal burning power plants. Current economic trends involve increased demand for freight transport, and hence increased international freight movements via diesel powered ships, and local freight distribution by diesel powered trucks. In addition, there is increased demand for individual travel using passenger cars by newly prosperous populations (but little decreased demand by already prosperous populations).

Per Capita Emissions

If overall emissions are to be held at or below current emission levels until 2050, then due to a growing world population - tipped to increase from around 6 billion in 2000 to around 9 billion in 2050 - per capita emissions must decrease by at least 30 percent. If overall emissions are to be reduced by 50% or more, then per capita emissions must decrease by at least 60 percent.

Currently, per capita emissions vary widely from country to country. Australia's per capita emissions are some 4 or 5 times world per capita emissions. Other industrialised countries are not far behind, and industrialising countries such as China will increase their per capita emissions significantly over the next few years, if they follow the energy and carbon intensive industrialisation path that many other countries have taken.

Per Capita Emissions Convergence

In order to reduce world per capita emissions by, say, 60 per cent, we could ask all countries to reduce their per capita emissions by 60 per cent. But it would hardly seems fair to ask poor countries with below average per capita emissions make forgo emissions growth, just so that rich, high per capita emitting countries like Australia only have to make modest modifications to their energy intensive economies.

If all countries agreed to converge on similar per capita emission levels by 2050, then the resulting economic and technological transition on the part of the richer countries would generate solutions that poorer countries could use to achieve economic growth without emissions growth.

Of course poorer countries, which haven't gone down the path of high fossil fuel consumption, offer many examples that wealthier countries may care to follow, such as building quality of life on strong communities rather than individual-focused material consumption.