Recently, many of my Greens colleagues and myself have received an email that appears to be circulating widely which makes a number of arguments disputing the science of climate change. The arguments are the same ones that climate change deniers have been using for many years and though they can be easily countered with basic scientific facts, the arguments keep coming. In the interest of not shying away from debate, below is my response to these all too common but false arguments. Most numerical data on climate change used here comes from the Intergovernmental Panel on Climate Change (IPCC) 4th assessment report (2007), available at http://www.ipcc.ch/publications_and_data/publications_and_data_reports.htm#1.
• False Argument “CO2 does not hold any more heat than any other gas”
The Truth - This is a statement that is flawed in a number of ways and can be countered with basic high school level chemistry. A wide range of gases, liquids and solids absorb, re-emit and store heat in different amounts, depending on a wide range of properties.
An easy to understand example of one of these properties is colour – place a black stone and a white stone in the sun and the black stone will very soon be hotter than the white one as black objects absorb more heat than white objects. Although carbon dioxide is the same colour as other atmospheric gases, it has other properties not detectable with the naked eye that means it absorbs and holds large amounts of heat, unlike other gases such as oxygen and nitrogen (the main two gases in the earth’s atmosphere). Skeptics will not be able to present any evidence to dispute this basic chemical fact.
With that bit of basic chemistry and the undisputed fact that human activities, primarily burning fossil fuels, are putting more carbon dioxide into the atmosphere, the reality of climate change falls very simply into place.
• False argument “CO2 is not a pollutant, it is essential to life”
The Truth- CO2 is both a pollutant and essential to life, the same as many other chemicals. Iron is essential to humans, yet a person with the disease haemochromatosis builds up excess iron in their bodies and this has severe negative health effects. On an even more fundamental level water is essential to life, yet no one argues that floods or tsunamis are not destructive because of this. The argument that because CO2 is essential to life it can’t be harmful is just as ridiculous.
• False argument “CO2 makes up such a small percentage of the atmosphere so it can’t be harmful”
The Truth - while it is true that CO2 is only 0.0387% of the atmosphere by volume its effect is disproportionate to its quantity. Like many other substances big increases in CO2 can induce large negative effects even if the overall increased amount is still a small proportion. Another example of such a substance is fluoride. Fatal fluoride poisoning can occur in a person who only takes in an amount of fluoride salts equal to only 0.0125% of their body weight yet fluoride in the water supply in even smaller amounts has yielded improved dental health in the population.
• False argument “Atmospheric CO2 levels have been higher in the past”
The Truth - current atmospheric levels of CO2 are higher than they have been any time in at least the last 650 000 years, a period far longer than that in which human civilisation has existed. It is true that millions of years ago CO2 concentrations were higher than they are now, but they had a dramatic effect on the world. Living organisms thrived under these conditions because they were vastly different to the organisms alive today and had specific adaptations to deal with these conditions. However organisms not adapted to live in those high CO2 conditions, such as humans and most other life of today, would have a much harder time of surviving because of massive climatic differences and other effects, just as a lion adapted to live in the African savannah would have a very hard time surviving in Antarctica. Likewise penguins survive in Antarctic environments because of specific adaptations, but these adaptations leave them most unsuited to the African savannah.
• False argument “Ocean levels have only risen 30mm since 1870”
The Truth - this figure is way off. According to the IPCC, sea levels have risen by over 80mm since the 1960s. Since 1993 sea levels have risen on average 3.1mm/year representing an acceleration of the 1.8mm/year average rise since 1963.
• False argument “Ice caps are expanding”
The Truth - while there has been expansion of some Antarctic ice sheets in the last few decades, due to the reductions in ozone depleting gases in the atmosphere and changed weather patterns around the Southern Ocean, overall global ice coverage is shrinking.
• False argument “The planet is not warming, it is cooling”
The Truth - global temperatures on average have risen 0.74 degrees C since 1905.The image below, produced by NASA’s Goddard Institute of Space Studies, shows the changes in surface temperature in 2001 relative to the average for 1951-1980. 11 of the 12 years from 1995-2006 (inclusive) were among the warmest 12 years since records began in the 1850s (this data only goes to 2006 because it is from the IPCCs 2007 report, there has been nothing to indicate that the trend stopped in 2006). It is often said that because 1998 was the warmest year on record the world has cooled since then. However there has always been year to year variation, the same as there is day to day variation – one does not deny temperatures will be warmer in summer if the 15th of November is a few degrees cooler than the 14th. The record of 1998 as warmest year ever will without doubt be broken soon.
• False argument “Solar power cannot produce large amounts of energy”
The Truth - this argument is out of date, and becomes more out of date every year as technology advances. Throughout the world solar thermal power plants, which produce steam that drives conventional turbines, with capacities measured in the hundreds of megawatts (MW) currently exist and plans for many more are on the drawing board. Energy can be stored cheaply (eg in vats of molten salt) so that solar thermal plants can run overnight or at other times when the sun isn’t shining. For a recent article on the state of this industry, see http://www.smh.com.au/business/handicapped-by-19thcentury-technology-20100202-nb3t.html.
• False argument “The maximum size for a wind turbine is 3MW”
The Truth Wind turbines with outputs of up to 5MW currently exist.
• False argument “Climategate shows that the science of climate change is fraudulent”
The Truth – “Climategate” was not the falsifying of figures by the IPCC. Rather it involved staff at a single British university who had their computer systems illegally hacked and a variety of emails taken out of context. These emails were used to try to show that the researchers had been selective about what data they used in order to support their research on climate change. Even if those allegations proved correct, this is one single isolated case – it does not invalidate the mass of other research (2500 scientists on the IPCC report alone) that has shown overwhelmingly that climate change is occurring.
• False argument “The IPCC admitted to lying about Himalayan glaciers”
The Truth - the IPCC have admitted that one paragraph in a 938 page report was inaccurate. Most documents of that size, exposed to as much scrutiny as IPCC reports are, would come up with many more errors.
I hope this information might come in useful next time you need to counter uninformed statements denying the science of climate change. Feel free to send it on to your networks. It is also worth remembering that there are many vested interests (by fossil fuel and mining companies amongst many others) in pretending that climate change isn’t real when it is. On the other hand there are far fewer organisations, with far less resources, who have an interest in pretending climate change is real when it isn’t. Some organisations, such as renewable energy companies, stand to make money as a result of action on climate change but these sort of enterprises only emerged after the science of climate change became well accepted. To imply that climate change is a conspiracy, started decades ago to create a market for what was at the time fringe technology, is simply ludicrous.