Greenhouse: Do I Need to Care?

A Google search of the word ‘greenhouse’ yields 31.5 million results. Don’t check them all; 12 or 13 thousand should be enough to convince you the greenhouse effect is both real and a good thing. Greenhouse is what makes Earth the ‘Goldilocks’ planet – not too hot (like Venus) nor too cold (Mars) – just right for us.

We have the atmosphere to thank for that. It prevents all of the Sun’s infra-red heat energy from being lost due to reflection. Think of it like a one-way insulator that traps just enough heat to keep the Earth’s temperature in the green zone for life as we know it.

The biggest greenhouse vector in the atmosphere is water vapour, which accounts for three to four times the greenhouse effect caused by CO2. However, we humans emit CO2 like there’s no tomorrow. Some say this will be a literal truth if we continue our profligate obsession with hydrocarbon-based energy.

Overwhelmingly, elite scientific opinion has it that elevated CO2 levels are warming the earth, and that most of this effect is ‘anthropogenic’ (down to us). It’s caused basically by our addiction to transport and electricity, and the intrinsic emission of CO2 when hydrocarbons are burned. On this there appears to be remarkable scientific agreement.

In Australia, we burn one litre of fuel, travel seven kilometres on average, and emit 2.1 kilograms of CO2. Times 29 billion annually.


The problem is global warming, not greenhouse. Some, like Jeremy Leggett, former professor of earth sciences at Imperial College, London, prefers “global overheating” and “climate meltdown”, to describe the problem. Al Gore, in An Inconvenient Truth, calls it the “climate crisis”. But, 20 years ago, some viewed even ‘global warming’ as too scary a term. With more zeal than a tobacco company obfuscating the link between cigarettes and lung cancer, Saudi Arabia and the US – the oil lobby, in other words – pushed the United Nations successfully in 1989 to remove ‘global warming’ references from climate-preservation resolutions and retain instead the somewhat less threatening term ‘climate change’. Future debate was therefore agnostically dumbed down and framed by a cosy-sounding expression that takes no position implicitly on the direction of the change. We wouldn’t want to frighten the kiddies, after all. Who knows – climate change might even be a positive thing: more water for the dams, say, or warmer winters for cold climes.


UK Chief Scientific Advisor Sir David King and former UK Meteorological Office boss Sir John Houghton both say global warming is a bigger threat than weapons of mass destruction, while John Browne, Group Chief Executive of BP in 2004 publicly acknowledged global warming as fact and discussed how to tackle it practically. It’s serious when an oil company jumps on board.

On June 21, 2004, 48 Nobel Prize-winning scientists signed a petition accusing US President George Bush and his administration of “Threatening the Earth’s future [by] ignoring scientific consensus on critical issues such as global climate change”.


Science is not always right. In 1616 the consensus scientific view was that the Earth was the centre of the universe, a position upheld by the Bible, which states several times that the Earth is fixed and cannot be moved. Galileo Galilei raised the ire of both Pope Urban VIII and the Holy Inquisition when his telescopic observations suggested that the Earth rotated about the Sun.

Almost 400 years later, science remains transitional. All it takes to ‘about face’ is robust new evidence. Could that happen with global warming?

Probably not. There is no credible scientific disagreement over whether global warming is real, whether human activity is the main cause, and whether the potential repercussions are so dangerous and profound that immediate action is warranted. Atmospheric CO2 levels are the highest they have been at any time in the past 650,000 years, by a long shot (at least 30 per cent higher), and this ‘off the chart’ period correlates nicely to the post-industrial world; recently the hottest world on record.

Debate does exist over the exact extent of potential consequences, however.

It is the media that grants global warming’s denial lobby the oxygen of publicity. Although there is no peer-reviewed scientific disagreement on basic global warming science, about half of all articles published in the popular press give the impression that uncertainty is rife between climate scientists. It is the press’s default position, giving equal weight to both sides of an argument even when no such underlying parity exists. A balanced view on this issue is, clearly, unbalanced.


In 2004, Australia’s greenhouse emissions totalled 565 million tonnes of CO2 equivalent, according to the federal Department of Environment and Heritage. Passenger cars emitted 42 million tonnes. Although this sounds like a lot, Australia contributes just 1.1 per cent to the world’s greenhouse emissions total. The big players are the US (30.3 per cent), Europe (27.7 per cent), Russia (13.7 per cent) and Southeast Asia, China and India (12.2 per cent).

A total of 169 developed nations have ratified the Kyoto Treaty, which aims to stabilise manmade greenhouse emissions at a level that prevents dangerous interference with the climate system. Only two developed nations have not: Australia and its big CO2-emitting brother the United States.


How much CO2 is in air? About 380 parts per million (ppm). Look at it like this. Take a one-metre cube of air, which is 1000 litres, then extract one stubby’s worth. (The level doesn’t go down much.) That’s the approximate proportion of CO2 currently present in the atmosphere, and what all the fuss is about. In the past 650,000 years, CO2 levels have been below 300ppm, but they will go above 600ppm (totally of the chart, in other words) in the next few decades unless dramatic changes are made. If the scientists are right, the consequences of that are potentially horrific – global depression, food and water crises, war, refugees, plague, sea level rise, large-scale habitat destruction, plus amplifying and irreversible warming – just like the Apocalypse from Revelation, only real.

We look back 400 years and sneer at those who believed the earth was the centre of everything. Will those who succeed us – if anyone does – look back with equal derision over how we saw it coming and just kept on burning regardless? It makes being stuck in peak hour traffic seem even more pointless an undertaking, doesn’t it?

John CadoganComment