During an interview a few days ago, Auckland mayoral candidate Vic Crone would not say if she believed the earth was warming due to man-made pollution, saying only: “Gosh, that’s a very contentious debate.”
Dr James Renwick, a professor of physical geography at Victoria University of Wellington, has slammed Crone’s statement. “The climate is changing and it is due to human activity and that is very clear from all sorts of lines of evidence,” he said. “To say that it’s very contentious suggests a real lack of understanding of the area.” The evidence showed that human influence was the dominant cause of global warming, Renwick said. “To try and say that we’re not sure is very backward thinking.” [emphasis added]
But that’s just not the case. The IPCC make no such categorical statements and official reports are actually soaked in uncertainty. It seems Professor Renwick’s certitude is at odds with the science. Still, perhaps NIWA states things more confidently. So I searched the NIWA web site in an attempt to corroborate this no-nonsense, activist-oriented doctrine that is convinced we cause all or most climate change. I typed ‘climate change evidence anthropogenic’ in the search box and got ten results. But none supported Renwick’s brusque response to Miss Crone. These are the NIWA articles the search returned:
- Understanding past changes in the Southern Ocean
- Climate change, global warming and greenhouse gases
- Greenhouse gases and climate sensitivity – insights from ice cores
- Climate Change
- IPCC Fourth Assessment Report (2007)
- New Zealand in a warming world
- Global climate models
- Our Far South events
- NIWA says greenhouse gas methane is on the rise again
- The WMO/UNEP 2002 ozone assessment: a New Zealand perspective
I should say there were no surprises here, and NIWA make it no easier to understand anthropogenic climate change since 2009 (when we challenged the national temperature data published on their web site), they make it more difficult. All these articles confuse the reader seeking the cause of human climate change, apparently presenting material only to obscure the lack of evidence. They are, in the legal terminology, prolix.
No. 1 Understanding past changes in the Southern Ocean
Not relevant. Learning about natural climate change so we can recognise anthropogenic climate change when (and if) it occurs.
No. 2 Climate change, global warming and greenhouse gases
Some relevance. An interesting summary but fails to explain how humanity is the cause of global warming and thus of climate change, although it comes close [my emphasis]:
Have greenhouse gas emissions caused global temperatures to rise?
Greenhouse gas concentrations have continued to increase in the atmosphere. This is due largely to human activities, mostly fossil fuel use, land-use change, and agriculture. About 47% of the warming effect of greenhouse gas increases over the last 100 years is due to carbon dioxide.
The second most important greenhouse gas produced by human activities is methane, which accounts for about 35% of the increased warming over the past 100 years (this is an important aspect of New Zealand’s greenhouse gas emissions, since sheep and cows produce methane).
Warming by greenhouse gases is offset in some regions by cooling due to small airborne particles generated by burning fuel. These are concentrated around areas of industrial activity in the Northern Hemisphere and in developing countries. (The cooling effect of aerosols over the New Zealand region is expected to be small).
Global mean surface temperature increased by 0.74°C between 1906 and 2005, a change which is unlikely to be entirely natural in origin. The balance of evidence suggests a discernible human influence on global climate. Much of the 1.8±0.5 mm yr-1 average global sea level rise between 1961 and 2003 may be related to the rise in global temperature.
These are oily words in weasel expressions shaped in the manner of scientific conclusions but in fact only invitations to draw our own. But NIWA is openly uncertain: the expressions “due largely to human activities”, “about 47% of the warming … is due to carbon dioxide”, “unlikely to be entirely natural” and “a discernible human influence” are incompatible with Renwick’s inflated assertions that it is due [implying ALL due] to human activity.
His most outrageous claim was human influence was the dominant cause of global warming. He used this unscientific statement to belittle Vic Crone’s “lack of understanding”, but I’m curious to know the data that justifies the extraordinary statement.
These public documents don’t corroborate Renwick’s overblown certainty. He says disparagingly: “To say that we’re not sure is very backward thinking.” But an examination of the scientific sources shows our mayoral candidate is absolutely correct to express doubt. The only reason for Renwick to disparage this is that he disagrees with it. Which is no justification for presenting that disagreement as scientific fact.
No. 3 Greenhouse gases and climate sensitivity – insights from ice cores
Not relevant. Ice core research.
No. 4 Climate change
Not relevant. Though it claims that “most” of the increase in temperature since 1950 was due to the increase in our emissions of carbon dioxide, and that came from “a vast array of evidence” and “physics”, it goes on simply to describe the consequences of climate change.
No. 5 IPCC Fourth Assessment Report
Not relevant. There are 14 references to increased emissions of the accursed substances carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), their change over time and their respective contributions to radiative forcing, and two references to aerosols and albedo citing tiny negative radiative contributions. There’s one reference to “new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities.” But there’s no mention of what that evidence might be.
No. 6 New Zealand in a warming world
Not relevant. Looks at the consequences of warming.
No. 7 Global climate models
Not relevant. Looks at the skill of models. Aptly, it asks “How Well do Models Simulate Observed Features of the Climate?” (exactly what we wanted to know). It says the Atmospheric Model Intercomparison Project (Gates, 1992) was to document the performance of GCMs in simulating the contemporary climate. Perfect! But inaptly, it gives us no results at all, saying very weakly that this has all been described at the First AMIP Scientific Conference (AMIP, 1995), and that “results have also been reported extensively in the open literature and in IPCC assessments.” So we’re on our own. When I have a little free time…
No. 8 Our Far South events
Not relevant. A glorious photographic celebration of NIWA research.
No. 9 NIWA says greenhouse gas methane is on the rise again
Not relevant. Describes our methane emissions and claims that methane affects temperature, but doesn’t describe how.
NIWA’s web page mentions methane (CH4) because farmed livestock, especially cattle and sheep, produce large quantities of it. What NIWA doesn’t say is that livestock are part of a cycle; when the herd or flock size is stable, there’s no change in the climate forcing from their methane. That’s before considering the inflated CO2 equivalence assigned to CH4. Methane is measured in parts per billion by volume (ppbv) because there’s so little of it in the atmosphere. Right now its concentration is about 1850 parts per billion, which is only 1.85 parts per million. So atmospheric methane, at 4,300,000,000,000 kg (4.3 billion tonnes) has less mass than a 500th part of the atmospheric mass of carbon dioxide (2.3 × 1012 (2,300 billion) tonnes). It is indeed far-fetched to imagine the tiny mass of methane having any thermal influence on the 5,150,000,000,000,000,000 kg (5.15 quadrillion tonnes) of the whole atmosphere. [12:00 noon 19 Sep 2016 – corrected conversion error; recalculated methane’s fraction of atmospheric carbon dioxide using mass, not volume. Thanks, Robin. – RT]
In the last 28 years CH4 has risen from 1675 ppbv to 1850 ppbv, or about 10%. This graph, though it ends in 2009, illustrates the strong increase in atmospheric methane since industrialisation began. Notice that the vertical axis doesn’t begin at 0, it begins at 600, which exaggerates the recent increase. Also, given the infinitesimal amount of atmospheric methane, you could double it a few times more without the climate noticing.
Not relevant. Ozone is weird.
NIWA make it hard on their web site to find the link between human activities or emissions and global warming or climate change. It’s as though they don’t want to reveal the details, because the details are doubtful.
But this is a matter that requires substantial public resources. Fighting climate change requires, apparently, decades of effort, many millions of expenditure and deep changes to our industrial infrastructure.
It really is not too much to expect that our publicly-funded scientists will be open with us. What’s it to be, James?