Responses to Questions & Objections on Climate Change

'Responses to Questions & Objections on Climate Change' by Dr Brett Parris, Chief Economist, World Vision AustraliaResearch Fellow, Monash University is the best dismantling of the flawed logic underpinning many climate myths currently being peddled - here is an excerpt of the summary from the Sydney Morning Herald, 7 December 2009, with the full list of contents below:

'AS WORLD leaders gather in Copenhagen, efforts to undermine public confidence in the science of climate change have intensified.

Sceptics have recently gained traction by exaggerating uncertainties in the research, said Brett Parris, a research fellow at Monash University and World Vision Australia's chief economist.

''They have been working very hard to create an impression there is a raging debate among research scientists about whether humans are contributing to climate change,'' he said. ''But that is not the case.''

With the advice of scientists, Dr Parris, who trained as a geologist, has developed a 48-page document outlining scientific responses to questions and objections proposed by sceptics.

''Those continuing to deny the links between greenhouse gas emissions and climate change are using specious arguments that have been repeatedly shown to be false, weak or irrelevant in the peer-reviewed scientific literature,'' he said.

The Herald has summarised some of his document's key points:

Climate change has happened in the past and what's happening now isn't outside the bounds of natural climate variability.

MOSTLY TRUE BUT IRRELEVANT
Sea levels were around 70 metres higher 45 million years ago, and 130 metres lower 21,000 years ago, for example, but this is no reason for inaction now. Most of the strong climate changes in the past were either local or regional. If global, they took many thousands of years to occur. There is no evidence of a global temperature rise of 5 degrees in a century, as could happen now.

It was warmer during medieval times when CO2 levels were lower.

PROBABLY FALSE BUT IRRELEVANT ANYWAY
It is possible temperatures in northern Europe between 800 and 1300 were slightly warmer than at present, but this appears to have been due to a local climatic effect in the north Atlantic Ocean, and cannot explain current warming.

Climate models are unreliable.

FALSE
Climate models are not perfect but they are based on sound science and have been able to replicate past observations to a good degree of accuracy and have anticipated effects such as global cooling from big volcanic eruptions.

There was a consensus among climate scientists in the 1970s that we would soon head into another Ice Age.

FALSE
This myth is repeated endlessly. A few research papers predicted cooling, but many more didn't and greenhouse warming dominated the scientific literature even then.

Global warming ended about 1998 and it's been cooling ever since.

FALSE
This is a case of cherrypicking. The years 1997 to 1998 saw a major temperature increase due to a strong El Nino, so if this is the starting point the years immediately after are, of course, relatively cooler. If 1997 or 1999 was chosen, it would show strong warming in the following years. What matters is the underlying warming trend over decades.

Warming is the sun's fault.

FALSE
Fluctuations in solar activity influence the world's climate but their effects have been taken into account and are not enough to explain observed changes...

Lack of warming in the lower atmosphere proves anthropogenic global warming is a myth.

FALSE
There is no longer a serious discrepancy, as claimed in a 2007 paper, between predictions of climate models and observations of the troposphere.

Coming out of the Ice Ages, the changes in CO2 came after the warming began, so CO2 doesn't affect atmospheric temperatures.

HALF TRUE BUT FALSE CONCLUSION
At the end of the Ice Ages, variations in the Earth's orbit and the angle of the axis warmed the planet again, followed 200 to 2000 years later by rising CO2. The CO2 amplified the initial warming, making the periods longer and warmer than they would otherwise have been.

Antarctica is cooling, so that proves the global climate isn't warming.

FALSE
While parts of Antarctica seem to be cooling, the continent is warming, and even the localised cooling and sea-ice expansion is consistent with climate change theory.

We should wait until there is more evidence before reducing greenhouse gas emissions.

WE'VE ALREADY DONE THAT AND THE EVIDENCE IS IN
The physics of the warming potential of greenhouse gases was worked out more than a century ago. The world is rapidly approaching points at which high risks of dangerous climate change are no longer avoidable.'



Introduction

1. The IPCC is a political body and its reports are scientifically unreliable

2. Science is not about consensus – Galileo was ridiculed by the authorities and the scientific establishment

3. There’s no consensus - 31,000 scientists signed a petition denying the link between greenhouse gas emissions and climate change

4. We should wait until there is more evidence before reducing greenhouse gas emissions.

5. Climate change has been happening throughout geological and human history. What is happening now is not outside the bounds of natural climatic variability.

6. Because what is happening now is within the realms of natural variability, we can’t say that humans are contributing to climate change.

7. Because what is happening now is within the realms of natural variability, it is not something to worry about. Species have always adapted.

8. It was warmer during medieval times

9. Climate models are unreliable

10. There was a consensus among climate scientists in the 1970s that we would soon be heading into another ice age

11. Global warming ended around 1998 anyway – it’s been cooling since then.

12. Our best strategy is simply to adapt to climate change.

13. CO2 exists only in very low concentrations in the atmosphere, therefore it cannot have significant effects.

14. CO2 is a weak greenhouse gas. Doubling of CO2 from its pre-industrial levels of 280 ppm to 560 ppm would only bring warming of about 1ºC.

15. CO2 is not a pollutant – it is completely natural and essential for life.

16. Any warming is the Sun’s fault.

17. Climate change is due to the effects of cosmic rays.

18. Lack of warming in the tropical troposphere (lower atmosphere) proves anthropogenic global warming is a myth.

19. Coming out of the ice ages, the changes in CO2 happened after the warming began, so CO2 doesn’t affect atmospheric temperatures.

20. Antarctica is cooling, so that proves the global climate isn’t warming

21. Action on climate change would ruin our economies

General remarks

Acknowledgments

Author Note

Endnotes

References

Useful Resources