By Dr Michael Edmonds
Climate change is an issue which needs to be debated scientifically, through careful and rational analysis of the facts. However, as the climate change debate intensifies a disturbing trend is emerging — more and more of the debate involves arguments reminiscent of a ’down and dirty’ political debate. Personal attacks, misrepresentation or selective use of facts, and irrelevant arguments now permeate the debate and cloud our understanding of climate change.
There is not enough space here to describe all of the inappropriate tactics used in the climate change debate. However, below are five common misleading arguments. My hope is that by recognising and challenging misleading and irrelevant arguments we can remove them from the public arena and focus on the real issues.
- ’Carbon dioxide isn’t toxic. Plants used it to grow.’
- This argument is pure misdirection. Increased carbon dioxide levels are worrying because they enhance the greenhouse effect. It is disturbing to see many self proclaimed ’experts’ resort to this misleading argument.
- ’How can carbon dioxide which is present in parts per million (ppm) have a significant effect on the atmosphere?’
- Carbon dioxide levels in the atmosphere have increased by 20% in the past 60 years to 387 ppm, hardly a minor variation. While measurements in ppm might seem low, many gases have significant effects at low levels. Hydrogen cyanide, for example, is lethal at concentrations above 135 ppm.
- ’Scientists can’t prove their claims with absolute certainty.’
- Scientists seldom make claims with absolute certainty, particularly with regard to complex systems such as climate. Indeed, I would be wary of absolutist claims coming from either side of the debate. Scientists tend to discuss events in terms of probability, for example, the most recent IPCC report suggests that there is a greater than 90% probability that anthropogenic global warming (AGW) is occurring. This means that AGW is so likely that the odds against it occurring are similar to the chance of tossing a coin four times and getting tails every time.
- ’This summer hasn’t been very hot, global warming can’t be true.’
- Short term weather occurrences (intense storms, colder than average winters, hotter than unusual summers) do not prove or disprove climate change. Climate change patterns are measured over decades and centuries to determine underlining trends that are not obvious in the seemingly chaotic nature of daily weather.
- ’Many scientists do not believe anthropogenic climate change is occurring.’
- Worldwide, more than fifty scientific organisations have issued statements that global warming is occurring and is most likely to be anthropogenic. While six scientific organisations remain non-committal, there are none who refute that AGW is occurring. Closer to home, approximately 70% of New Zealand scientists and technologists agree that AGW is occurring, with 9% disagreeing, and 21% non-committal.
Some scientists who do not accept AGW are carrying out research in order to demonstrate their misgivings scientifically. This is to be applauded. Science does not fear the results of legitimate research. Unscrupulous opponents of AGW, however, have resorted to attacking scientists and science. Claims of a scientific conspiracy appear to have gained some public support even though these claims are based on disingenuous interpretations of hacked emails and exaggeration of errors in IPCC reports. Fear and suspicion may be powerful manipulators of public opinion, but they have no place in scientific debate.
If we are to make progress in understanding AGW both individually, and as a society, we must learn to see through the dirty tricks used in the climate change debate. We all have the capability to recognise and challenge misleading arguments. Removal of these arguments from the public arena can only serve to bring clarity to the climate change debate.
Dr Michael Edmonds is an educator, researcher and manager at Christchurch Polytechnic Institute of Technology. He has strong interests in the communication and promotion of science.