Publication Name

KICK THE HABIT

THE PROBLEM

If you want to reduce

greenhouse gases

, it helps to know where on Earth

they come from. So what are some of the obvious ways of emitting GHGs

that we may all be involved in, probably without even realising it? Here are

some of the really glaring ones.

Energy for...

Energy is involved in just about everything we do. Depending on the

source

of the energy, the efficiency of its use and the waste created in the process,

its use and production emits from zero to enormous amounts of GHGs.

Energy generation is the single most important activity resulting in GHG emis-

sions, in particular because most of it is produced from fossil fuels such as oil,

gas and coal, the latter being mainly used to generate electricity. Coal, par-

ticularly brown coal (also called lignite), is the energy source with the highest

GHG emissions per energy unit. Burning coal generates 70 per cent more CO

than natural gas for every unit of energy. At the same time, coal is cheap and

is the most widely available fossil fuel. According to the World Coal Institute, it

is present in almost every country, with commercial mining in over 50. It is also

the fossil fuel with the longest predicted availability. At current production levels

coal will be available for at least 155 more years (compared with 41 years for oil

and 65 for gas).

But current production levels will not remain static. While coal use is falling in

Western Europe it is rising in Asia and the United States. The Asia-Pacific region

will be the main coal market – with 58 per cent of global coal consumption by 2025

– if current trends continue. The region is home to the largest consumer (China),

the largest exporter (Australia) and the largest importer (Japan) of coal globally.

International commitments, the progress of new technologies such as Carbon

Capture and Storage (CCS, see page 88) and increased efficiency of power grids,

industrial processes and so on are all ways to reduce coal-related GHG emissions.

But ultimately the challenge is to develop a clean, widely available and affordable

alternative to satisfy the world’s energy needs (see page 144).

The greenhouse effect is an important mechanism of temperature regulation. The

Earth returns energy received from the sun to space by reflecting light and emit-

ting heat. Part of the out-going heat flow is absorbed by greenhouse gases and

re-irradiated back to the Earth. Though they occur naturally, human activities

have significantly increased their presence in the atmosphere. Greenhouse gases

vary considerably in amounts emitted, but also in their warming effect and in the

length of time they remain in the atmosphere as active warming agents.