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Recently in New York there was the biggest conference ever held of scientists and others sceptical of one or more of the following propositions: human activity is warming the globe; this poses a serious threat; and something significant can be done about it.
Attending was Jennifer Marohasy, who discusses some new data presented at the conference.
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Transcript This transcript was typed from a recording of the program. The ABC cannot guarantee its complete accuracy because of the possibility of mishearing and occasional difficulty in identifying speakers.
Michael Duffy: Recently in New York there was the biggest conference ever held of scientists and others who are sceptical of one or more of the following propositions; human activity is warming the globe, this poses a serious threat to the future of humanity, and something significant can and should be done about it. Well, as that somewhat clumsy sentence indicates, those sceptical of the current orthodoxy on climate change don't speak with the degree of certainty and unanimity we often hear by many of those in favour of it.
Paul Comrie-Thomson: The conference was ignored by the environmentally orthodox Australian media, which is their and their readers' and viewers' loss because some very important new scientific data emerged.
Michael Duffy: Biologist Jennifer Marohasy attended the conference and she joins us in a moment. Jennifer Marohasy works for the Institute of Public Affairs which, like the Heartland Institute which was the main organiser of the conference, has received funding from fossil fuel and energy companies. I spoke to Jennifer Marohasy earlier today. I first asked who attended this gathering.
Jennifer Marohasy: A great diversity of people; meteorologists, geologists, statisticians, economists, astrophysicists. I'm a biologist, and there was at least one other biologist there, Mitch Taylor, he's a polar bear specialist. We were there to talk about climate, climate change, the sciences of global warming. It was a gathering of so-called sceptics, but I guess I should make it clear that we're not sceptical of climate change, climate has always changed, but we are sceptical to the extent to which carbon dioxide drives warming.
Michael Duffy: The conference was virtually ignored by the Australian media, but over the last few days the media here did give a lot of coverage to the thinning of glaciers around the world, and in most cases that story was accompanied by the claim that was caused by the warming of the Earth. However, if we look at the best records we have for the past decade, is the Earth still warming?
Jennifer Marohasy: No, actually there has been cooling, if you take 1998 as your point of reference. If you take 2002 as your point of reference then temperatures have plateaued. This is certainly not what you'd expect if carbon dioxide is driving temperature because carbon dioxide levels have been increasing, but temperatures have actually been coming down over the last ten years.
Michael Duffy: Is this a matter of any controversy? Would the people, for example, behind the IPCC report disagree with what you've just said?
Jennifer Marohasy: Actually, no, the head of the United Nations Intergovernmental Panel on Climate Change, the IPCC, has actually acknowledged...he talks about the apparent plateau in temperatures so far this century. So he recognises that in this century, over the eight years temperatures have plateaued. If you look over the last ten years since the peak in 1998, temperatures have actually been coming down. This is not what you'd expect, as I said, because if carbon dioxide is driving temperature then you would expect that given carbon dioxide levels have been continuing to increase, that temperatures should be going up. But in actual fact they've been coming down since 1998. If you look since 2001, 2002, they've plateaued. So very unexpected, not something that is being discussed, it should though be being discussed because it's very significant.
Michael Duffy: It's not only that it's not discussed, we never even hear it, do we? Whenever there's any sort of weather event that can be linked into the global warming orthodoxy it's put on the front page. But a fact like that, which is that global warming stopped a decade ago, is virtually never reported, which is extraordinary.
Jennifer Marohasy: It is extraordinary, though I perhaps should pick you up on 'global warming has stopped'. It has stopped for the last ten years, but that's a very short timeframe. If you look over the last 100 years, it's mostly been warming over the last 100 years but there was some cooling from 1940 through to 1975 and now there appears to be some cooling since 1998. But if you look at the longer timeframe, say, since the last glacial maximum, well, that's going back, say, 16,000 years, then there actually has been significant warming, and sea levels of course have risen over 100 metres over this period. So the last eight to ten-year dip may just be a dip, and there may be continued warming into the future, or it could be the end of this interglacial warm period and we could go into another ice age. We don't know what the future holds.
Michael Duffy: Yes, but as you say, there has been a dip and it doesn't seem to fit in with the notion that carbon is directly linked to temperature. People like Kevin Rudd, Ross Garnaut are speaking as though the Earth is still warming at an alarming rate, but what is the argument on the other side? What would people associated with the IPCC say to explain the dip?
Jennifer Marohasy: Well, the head of the IPCC has suggested natural factors are compensating for the increasing carbon dioxide levels, and I guess to some extent that's what sceptics have been saying for a long time, that yes, carbon dioxide will give you some warming but there are a whole lot of other factors that may compensate or that may augment the warming from the elevated levels of carbon dioxide. There's been a lot of talk about the impact of the Sun and that maybe we're going to go through or we're entering a period of less intense solar activity and this could be contributing to the current cooling.
Michael Duffy: Can you tell us something about the data? Are we getting better at measuring the Earth's temperature?
Jennifer Marohasy: Basically temperature has been measured in Europe with thermometers since the 17th century. The network of temperature collection stations based on thermometers has increased over time since the 17th century, though there was a decrease in the number of these thermometers in white boxes with the disintegration of the Soviet Union. We lost a lot of temperature stations in places like Siberia.
But it's also worth noting we've only had records for the polar regions since the 1940s, and it's recognised that thermometer measurements are affected by things like heat island effects, so as countries become more industrialised, there's more bitumen, there's more cars, there's more air conditioners, you're going to end up with the appearance of warming even though there's actually not. Only since 1979 have we had satellite measurements and actually only since...well, Roy Spencer talked a lot at the conference in New York about how much better data collection has got since, for example, 2002.
Michael Duffy: This was when NASA's Aqua satellite was launched, wasn't it?
Jennifer Marohasy: That's right.
Michael Duffy: Can you tell us a bit more about NASA's Aqua satellite because I understand some of the data we're now getting from it is quite important in our understanding of how climate actually works.
Jennifer Marohasy: That's right. The satellite was only launched in 2002 and it enabled the collection of data, not just on temperature but also on cloud formation and water vapour. What all the climate models suggest is that when you've got warming from additional carbon dioxide this will result in increased water vapour, so you're going to get a positive feedback. That's what the models have been indicating. What this great data from the NASA Aqua satellite...and the first time this data has been able to be collected is 2002 so we've got a little bit of data now, it's actually showing just the opposite, that with a little bit of warming, weather processes are compensating, so they're actually limiting the greenhouse effect and you're actually getting a negative rather than a positive feedback.
Michael Duffy: The climate is actually...in one way anyway, it's more robust than was assumed in those climate models.
Jennifer Marohasy: That's right, weather processes are adjusting. So, for example, you're getting more low cloud cover and less high cloud cover. For example, when it rains you get a release of water vapour, and what they're finding is you're getting less water vapour, less high cloud cover when there's some warming from other things including, for example, potentially, if you look at the big picture, carbon dioxide. These findings actually aren't being disputed by the meteorological community. They're having trouble digesting the findings, they're acknowledging the findings, they're acknowledging that the data from NASA's Aqua satellite is not how their models predict, and I think they're almost about to recognise that the models really do need to be overhauled and that when they are overhauled they will probably show greatly reduced future warming projects as a consequence of carbon dioxide.
Michael Duffy: From what you're saying it sounds like the implications of this could be considerable because they would change our idea or the current orthodoxy regarding the likely future of climate change, and therefore they could have implications for how we respond to climate change for future IPCC reports and even for steps taken by nations such as Australia.
Jennifer Marohasy: That's right, very much so. The policy implications are enormous. The meteorological community at the moment is really just coming to terms with the output from this NASA Aqua satellite and Roy Spencer's interpretation of them. His work is published, his work is accepted, but I think people are still in shock at this point in time.
Michael Duffy: Who's Roy Spencer? Is he with NASA?
Jennifer Marohasy: Roy Spencer leads the team that's analysing the temperature data from NASA's Aqua satellite, that's right.
Michael Duffy: And at the end of the conference you signed something called the Manhattan Declaration. What's that?
Jennifer Marohasy: The Manhattan Declaration basically talks about the economic implications of moving to a low carbon economy and that the economic implications are going to be significant but the impact on climate is going to be basically zero. So it's suggesting that some of the policy that's being advocated is going to make us poorer and not change climate.
Michael Duffy: It's got a few nice lines in it. One of them is this, that carbon dioxide is not a pollutant but rather a necessity for all life. In the context of what we've been hearing in the last few years I think that might actually come as a surprise to many people.
Jennifer Marohasy: That's right. We need carbon dioxide, plants breathe it in, we breathe it out, it's everywhere, and what Roy Spencer's work with that Aqua satellite has been showing is that climate systems can cope and adjust with elevated atmospheric levels of carbon dioxide.
Michael Duffy: Another line in the declaration that would come as a surprise to anyone who takes their science from the front page of the newspapers is that warmer weather is generally less harmful to life on Earth than colder weather. I think it's really great that these basic scientific points have been stated so publicly.
Jennifer Marohasy: Absolutely. Certainly people used to talk about periods like now where we actually are living during an interglacial warm period as being a period when life tends to flourish, when there's more opportunity for...anyway, it's the next ice age that we really should be worrying about, not a little bit of warming.
Michael Duffy: Jennifer Marohasy is a biologist, the director of the Australian Environment Foundation and a senior fellow with the Institute of Public Affairs which has received funding from fossil fuel and energy companies.
Guests Jennifer Marohasy Director, Australian Environment Foundation Senior Fellow, Institute of Public Affairs.
Further Information The 2008 International Conference on Climate Change
Presenter Michael Duffy
Producer Ian Coombe
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