The world has spent billions of dollars, and will probably spend trillions more, on a “problem” that is invisible to the naked eye. Millions of taxpayers in Western countries are having their wallets syphoned so governments can study and prepare for global warming. Policies to reduce greenhouse emissions could potentially cost the lives of many people in poorer parts of the world, by slowing economic development.
The trouble is, the weather doesn’t seem to be acting the way climate scientists say it should, and there is no sign of the catastrophic climate changes that are supposedly going to happen in the near future.
The United Nation’s Intergovernmental Panel on Climate Change released it’s Summary for Policy Makers on February 2, 2007. This is a summary of the much larger Fourth Assessment report which will be released in May.
There were no real surprises in the report. Apparently the scientists are more confident than they were in 2001, when the last Assessment Report was released, that the climate is changing and that humans are to blame. We will have to wait until May to see how they justify this.
No matter, the headlines were up and running on front page stories around the nation, although the Adelaide Advertiser’s headline, “Chilling Warning”, seemed a touch inappropriate for a story about global warming.
Tim Flannery was forecasting the end of all life; French President Jacques Chirac said the future of humanity was at stake, and called for a United Nations body with increased power over nations that exceeded their emission quotas; Kevin Rudd decided to convene a climate summit to look for solutions (just don’t frighten the voters by mentioning the “N” word); Western Australia decided a carbon tax on the mining industry might be worth a try if they could get away with it; and South Australian Premier and Minister for Climate Change, Mike Rann, commissioned some more windmills to put on government buildings.
So it would be reasonable the think that the climate must be getting quite hot to justify this flurry of political activity.
Not really. Global temperature (and how exactly do they measure it?) in 2005 was about 0.7C warmer than in 1854, 0.4C warmer than in 1878, and 0.3C than 1943. It was about 0.1C cooler in 2005 than in 1998, and there has been virtually no increase in global temperature since then. On the other hand, it was about 1.0C warmer in 2005 than in 1913, the coolest year on record.
During the rapid increase in atmospheric carbon dioxide that followed World War II, global temperatures actually fell. In 1975 there was a sudden change in trend, and temperatures began to rise. 1998 was the warmest year in the instrumental record, and seems to have been unusual due to the very pronounced El Nino that year. Since then, temperature has not risen to any significant degree. While all this was going on, carbon dioxide has been steadily rising.
How is the weather that you and I experience every day changing? Not by very much. Sometimes there is unseasonably warm weather, usually attributed to global warming by the media. At other times there is unseasonably cold weather, which is usually just reported factually. There is nothing unusual about this, and any effect of the increased carbon dioxide in the air is completely invisible to normal human senses.
The same goes for rainfall. Droughts, floods and unseasonable rainfall are nothing new, and have happened since records began, and undoubtedly for many thousands of years before that. Ditto for sea level. There has been a slow rise ever since the end of the last ice age. I went to the beach on the weekend, and it was in exactly the same place it was when I went there in the 60s.
How do the scientists correlate the minute rise in temperature over the last 150 years with the increase in carbon dioxide, from about 270 parts per million (ppm) to about 380 ppm? They construct computer programs, called General Circulation Models, or GCMs, which are supposed to account for the magnitude and direction of all the factors, both natural and human, that force the climate to cool or heat. They say that when these models are run, the only way to account for the observed temperature is that greenhouse gases added by humans are heating the atmosphere, and without the human added greenhouse gases, temperatures would not have risen.
This approach makes some breathtaking assumptions. First, it is assumed that absolutely every factor that can affect climate is known. Then each factor, and the interactions between them, must be accurately calculated by the model. Yet the IPCC itself says that the level of scientific understanding of factors such as clouds and solar irradiance is low. Other scientists have suggested climate forcing factors such as the effect of galactic cosmic rays, which are entirely ignored by the GCMs.
Global warming is an issue that seems to cause a degree of anxiety in people, to the extent that politicians are driven to take some sort of symbolic action. (We don’t really believe that a country emitting about 1.5 per cent of global greenhouse gases is going to affect world climate by building a few wind farms.) Global warming is a virtual experience, some people believe in it because they read and hear about it in the media, but none of us are actually experiencing it to any detectable degree.
Climate has changed many times in the past, and humans with very limited technology have been able to adapt and thrive. There is no reason to lose confidence in our ability to cope with our current benign and stable climate.