Climate science myths that refuse to die
This is an edited summary of the article “Have you got climate zombies? We debunk the myths that refuse to die”, by environment reporter Nick Kilvert on the ABC website. This edited summary is interspersed by other observations and evidence which has since come to light.
"Climate zombies" is a reference to theories that were convincingly refuted years ago, but still refuse to die. For a rebuttal of the views of Christopher Monckton, equally applicable to climate zombie myths generally, see also the comprehensive analysis of Professor John Anderson, cited also on the previous page. The skeptical science webpage lists and responds to no less than 149 so-called "global warming and climate change myths". Click on "view all arguments" in the left hand pane. The ethos of the skeptical science page is skepticism about global warming skepticism.
Here is a sampling of Kilvert's zombies, and one or two more:
- The concentration of CO2 in the atmosphere is so small as not to be worth worrying about.
The idea that the concentration of CO2 in the atmosphere is so small as to be unable to wreak the climate chaos it is accused of causing has been convincingly refuted by Professor Mark Howden, director of the Climate Change Institute and a vice chair of the IPCC:
o "Anyone who says that this doesn't happen has to catch up with 150 years’ worth of science."
o "The argument that small concentrations don't matter is an absolutely ridiculous one. o "You wouldn't propose that anyone take half a teaspoon of potassium cyanide — it's a small concentration in your body but we know it's fatal." o “The scale of the increase [of CO2] is huge. In my lifetime it's gone up 100 parts per million." |
- · Milankovitch cycles [1]
Here, the prevailing myth is that so-called Milankovich cycles - cyclical variations in the Earth's orbit and the tilts and wobbles of its axis and named after the Yugoslavian climatologist who recognised their existence in the 1920s - are the predominant force behind the current phase of global warming.
Over the last million years or so, the distribution of solar radiation on the Earth has varied in a more or less regular way because of variations in the Earth’s orbit around the sun. Three factors are relevant here.
- Firstly, the Earth’s orbit, although nearly circular, is actually an ellipse and the eccentricity of its orbit varies.
- Secondly, the Earth also spins on its own axis, the axis or spin being tilted with respect to the axis of the Earth’s orbit.
- And the third variation is as regards the time of the year when the Earth is closes to the sun (the Earth’s perihelion)
However, these cycles wax and wane over thousands to hundreds of thousands of years and don't correlate with today's rapid temperature increase. In fact, studies of the relationship between the ice ages and the Earth’s orbital variations show that the size of the climate changes is larger than might be expected from forcing by the radiation changes alone, and other processes that enhance the effect of the radiation changes (in other words, positive feedback processes) have to be introduced to explain the climate variations.
One such feedback arises from the changes in CO2 influencing atmospheric temperature through the greenhouse effect, illustrated by the strong correlation in the climatic record between average atmospheric temperature and carbon dioxide concentration. As a result, climates of the past cannot be modelled without taking the greenhouse feedback into consideration.
Right now, Earth's tilt is in the decreasing phase, which means the northern hemisphere, where the majority of Earth's landmass is located, is slightly less tilted towards the Sun. So, if Milankovitch cycles were the dominant driver or "forcing" on our planet, we'd be in a cooler phase where temperatures should be slightly down on average. The projection is that the next ice age will not occur for something like 30,000 years.
- The so-called recent “pause” in global warming
Thanks in part to an extreme El Nino, 1998 was an exceptionally hot year globally. At the time, it was the hottest on modern record at 0.62 degrees Celsius above pre-industrial levels. But warming isn't linear, it goes up and down a bit, so inevitably the following years were a bit cooler.
If you take 1998 as year one, and then look forward to 2002, it appears that warming has stopped or is trending slightly downwards.
If you ignore the black trend line, it looks like there was a “warming pause” in the early 2000s. But compare this NASA graph with the one below.
Climate is measured at a minimum of 30-year periods, according to Professor Will Steffen and Annika Dean of the Australian National University and the Climate Council. As time went on, 2005 was hotter than 1998, 2010 hotter than 2005, and 2014, 15, 16, 17 and 18, hotter than all of them. 1998 now clings on to 10th place in the global temperature books, with the hottest nine all since 2005.
Climate is measured at a minimum of 30-year periods, according to Professor Will Steffen and Annika Dean of the Australian National University and the Climate Council. As time went on, 2005 was hotter than 1998, 2010 hotter than 2005, and 2014, 15, 16, 17 and 18, hotter than all of them. 1998 now clings on to 10th place in the global temperature books, with the hottest nine all since 2005.
(Graph: NASA)
Unless it's a seriously anomalous year, 2019 looks almost certain to knock 1998 out of the top 10. Short term fluctuations do not show the overall trend in climate
Here are some other examples of climate denier/sceptics who choose to distort the statistics by relying on an anomaly taken out of context as proof of a generality to prove their own particular preconceived point of view - such as relying on the statistics of fires worldwide for the last 50 years to prove that the world’s fires are diminishing in frequency as carbon emissions rise when the timeframe the focus of the investigation to which they are referring was over 70,000 years and came to the opposite conclusion.
Or saying that there were high CO2 levels up to 4,000 ppmv in a period of glaciation during the Ordovician-Silurian and Jurassic-Cretaceous periods, when climate science as we now know it predicts that there should have been runaway global during warming these periods because of that. However, the period of glaciation in question was no more than a blip during an otherwise warm era due to a coincidence of conditions.
An instance of this may be found in the now defunct Catholic religious magazine Annals Australia for 10 August 2019 in an article entitled “Climate Science at the Crossroads” by one Howard Thomas Brady. The synopsis at the heading of the article epitomises its argument: “Animals and plants have thrived for missions of years in carbon dioxide concentrations between 1500 and 2000 ppm, and sometimes even higher. The Earth has normally been at least 3degrees to 5 degrees warmer. The present levels of carbon dioxide are so low that despite some rise in carbon dioxide levels in the last 150 years, we are still in a carbon dioxide drought”. The true situation may be found in a piece entitled “Do high levels of CO2 in the past (when the climate was cooler) contradict the warming effect of CO2?” on the Skeptical Science page.
Sure, the Earth’s climate is constantly changing due to things like Milankovitch cycles, variations in solar activity, as well as changes in greenhouse gas quantities in the atmosphere, and it mostly happens on timescales of tens to hundreds of thousands of years and there have also been some really fast warming events.
In the end-Permian extinction about 252 million years ago, about 90 per cent of species died. Researchers believe it was caused by CO2 from massive volcanic eruptions in Siberia, wildfires, plus high emissions of methane. The CO2 emissions that kickstarted the end happened over a period of between 2,100 and 18,800 years. The average temperature on Earth increased by up to 10C.
In our present predicament, the IPCC's worst-case scenario is 4.8C by the end of the century, and we know this is definitely due to humans because the isotopic signature of carbon dioxide in the atmosphere has changed and this reflects the fact that additional carbon dioxide is being added from fossil fuels. An isotopic signature may best be described as a set of ratios of the abundances of different isotopes of specified elements in a sample, used as a diagnostic test of the sample's origin, or of its age. Carbon dioxide from fossil fuels has a different isotopic signature (from carbon dioxide from say, decomposing trees or grass. Carbon dioxide levels for as far back as our ice cores can show have never been as high as they are today.
And meanwhile, volcanoes, sometimes blamed for releasing more CO2 than humans, release only about 1 per cent of the CO2 that we do.
Yes, but plants not only need carbon dioxide to grow. They need a full set of nutrients, things like phosphorus, nitrogen, potassium, calcium, magnesium and sulphur.
David Ellsworth, an environmental scientist from Western Sydney University, exposed areas of mature eucalypt forest to high levels of CO2 for three years. While there was more photosynthesis in the leaves, the trees didn't grow any more than the control groups that were exposed to ambient air.
"Growth is limited by nutrients in the soil," Professor Ellsworth said. "What we've found is that low phosphorus levels really prevent the kind of growth that predictions would tell you to expect. But trees that were given extra phosphorus and no extra CO2 increased their growth rate by about 35 per cent. Increased CO2 will only make a difference to tree growth if we distribute fertiliser with it.
Palaeoclimate data [mostly proxy data from coral and tree records] shows warmer than average conditions, mostly in Europe and North America for at least some parts of AD 800-1200 — known as the Medieval Warm Period. But analysis of the data published in the journal Nature in July 2019 shows that:
The individual teams of researchers in the studies involved used seven different statistical techniques to reconstruct global temperatures during the so-called Common Era starting 2000 years ago and separately came to the conclusion that global heating in recent decades is of a pace and magnitude unique in at least the past two millennia, with human-caused climate change now "overwhelming" natural variability. They also studied variability over decades and centuries, including the Medieval Warming Period and the Little Ice Age, and found that no era had the spatial extent or intensity of the heating over recent decades.
Certainly CO2 has been at higher levels than today when temperatures were much cooler, but that was when things like low solar activity or Milankovitch cycles were the dominant climate forcings, or factors. There are a multitude of things that can affect the climate, and CO2 is just one of them. When all things are equal, and you take one factor and ramp it up or down, it's going to make a change.
We can observe this from the Pliocene epoch, a mere 5.3 to 2.6 million years ago. Background climate factors were similar to today, and like today, CO2 was around 400 parts per million. At the time, temperatures were about 3C to 4C warmer than today, sea levels were about 20 metres higher, and there were trees in Antarctica. See also above on the Ordovician era.
Here, the contention is that there's a group of governments and global elites that stand to benefit from hoaxing the world into believing the climate is changing. It is alleged that these so-called elites conscripted groups including NASA, the Australian Bureau of Meteorology, the UK Met Office, the CIA, thousands of climate scientists and universities wordwide, among a raft of others, to contrive an environmental crisis. However, the reality is that not acting on climate change will punish the poor. The IPCC predicts millions will be displaced if warming hits 2 degrees.
Many of those will be in low-lying areas of developing nations including Bangladesh, and Australia's island neighbours in the South Pacific. Increases in extreme weather events also disproportionately affect areas with poor housing and infrastructure, and where subsistence farmers can be quickly undone by drought.
It is true that CO2 has risen after the temperature has started going up, during some periods of warming throughout history, but the conclusion that therefore CO2 doesn't cause warming, isn't sound. There are in fact many forcings that cause climate change, and there are things called positive feedback loops.
So for instance, deglaciation that began around 20,000 years ago was initially caused by changes in Earth's orbit of the Sun. This initial temperature increase warmed the oceans, and warmer oceans, as research shows, release more CO2. That CO2 then increased in the atmosphere, and in turn created even more warming, that in turn released more CO2 from the oceans — a positive feedback, according to Professor Will Steffen and Annika Dean of the Australian National University and the Climate Council. "These positive carbon cycle feedbacks initially follow temperature rises, but then amplify them by causing further warming."
And CO2 isn't the only greenhouse gas that is involved. "Warmer temperatures can also melt permafrost [frozen subsoil] in the Arctic, causing the release of methane, a potent greenhouse gas," they said.
The reality is that climate scientists don't earn any more than researchers in other areas, and science isn’t a particularly lucrative profession. "According to the ABS, people employed in full-time jobs related to professional, scientific and technical services earned an average of $1,872 per week in the year to November 2018. This is more than some industries, but less than some other industries, such as mining, which paid on average $2,696 per week to full-time employees over the same period."
On the other hand, the fossil fuel industry is worth nearly $5 trillion, according to a Bloomberg New Energy Finance report from 2014.
What do the figures actually say? According to a 2009 report by the IUCN Polar Bear Specialist Group, of the 19 recognised subpopulations of polar bears, 8 are in decline, 1 is increasing, 3 are stable and 7 don’t have enough data to draw any conclusions.
Estimates place the overall number of bears at about 20,000 to 25,000. Polar bears are classed as vulnerable by the World Conservation Union (IUCN) and listed as a threatened species under the US Endangered Species Act. The reason polar bears have been classed as threatened comes from the impacts of future climate change on the bears’ habitat. Current analysis of subpopulations where data is sufficient clearly shows that those subpopulations are mainly in decline. Further habitat degradation will increase the threats to polar bears.
The Australian Coalition Government inherited a 755 million tonne emissions "deficit" when it cam to power and that it has been turned around by 1.1 billion tonnes: https://www.abc.net.au/news/2019-10-24/zombie---angus-taylor-emissions-abatement-kyoto-protocol/11630780 See also https://www.abc.net.au/news/2019-04-11/fact-check-coalition-emissions-reduction-angus-taylor/10936652
[1] This section represents an edited version of portion of Chapter 4 of Sir John Houghton's Global Warming - The Complete Briefing, 5th edition, Cambridge University Press. 2015, pages 83-84.
Unless it's a seriously anomalous year, 2019 looks almost certain to knock 1998 out of the top 10. Short term fluctuations do not show the overall trend in climate
Here are some other examples of climate denier/sceptics who choose to distort the statistics by relying on an anomaly taken out of context as proof of a generality to prove their own particular preconceived point of view - such as relying on the statistics of fires worldwide for the last 50 years to prove that the world’s fires are diminishing in frequency as carbon emissions rise when the timeframe the focus of the investigation to which they are referring was over 70,000 years and came to the opposite conclusion.
Or saying that there were high CO2 levels up to 4,000 ppmv in a period of glaciation during the Ordovician-Silurian and Jurassic-Cretaceous periods, when climate science as we now know it predicts that there should have been runaway global during warming these periods because of that. However, the period of glaciation in question was no more than a blip during an otherwise warm era due to a coincidence of conditions.
An instance of this may be found in the now defunct Catholic religious magazine Annals Australia for 10 August 2019 in an article entitled “Climate Science at the Crossroads” by one Howard Thomas Brady. The synopsis at the heading of the article epitomises its argument: “Animals and plants have thrived for missions of years in carbon dioxide concentrations between 1500 and 2000 ppm, and sometimes even higher. The Earth has normally been at least 3degrees to 5 degrees warmer. The present levels of carbon dioxide are so low that despite some rise in carbon dioxide levels in the last 150 years, we are still in a carbon dioxide drought”. The true situation may be found in a piece entitled “Do high levels of CO2 in the past (when the climate was cooler) contradict the warming effect of CO2?” on the Skeptical Science page.
- The current warming means that the Earth's climate is a manifestation of the Earth’s natural cycles
Sure, the Earth’s climate is constantly changing due to things like Milankovitch cycles, variations in solar activity, as well as changes in greenhouse gas quantities in the atmosphere, and it mostly happens on timescales of tens to hundreds of thousands of years and there have also been some really fast warming events.
In the end-Permian extinction about 252 million years ago, about 90 per cent of species died. Researchers believe it was caused by CO2 from massive volcanic eruptions in Siberia, wildfires, plus high emissions of methane. The CO2 emissions that kickstarted the end happened over a period of between 2,100 and 18,800 years. The average temperature on Earth increased by up to 10C.
In our present predicament, the IPCC's worst-case scenario is 4.8C by the end of the century, and we know this is definitely due to humans because the isotopic signature of carbon dioxide in the atmosphere has changed and this reflects the fact that additional carbon dioxide is being added from fossil fuels. An isotopic signature may best be described as a set of ratios of the abundances of different isotopes of specified elements in a sample, used as a diagnostic test of the sample's origin, or of its age. Carbon dioxide from fossil fuels has a different isotopic signature (from carbon dioxide from say, decomposing trees or grass. Carbon dioxide levels for as far back as our ice cores can show have never been as high as they are today.
And meanwhile, volcanoes, sometimes blamed for releasing more CO2 than humans, release only about 1 per cent of the CO2 that we do.
- Plants need CO2 to grow and the more the better.
Yes, but plants not only need carbon dioxide to grow. They need a full set of nutrients, things like phosphorus, nitrogen, potassium, calcium, magnesium and sulphur.
David Ellsworth, an environmental scientist from Western Sydney University, exposed areas of mature eucalypt forest to high levels of CO2 for three years. While there was more photosynthesis in the leaves, the trees didn't grow any more than the control groups that were exposed to ambient air.
"Growth is limited by nutrients in the soil," Professor Ellsworth said. "What we've found is that low phosphorus levels really prevent the kind of growth that predictions would tell you to expect. But trees that were given extra phosphorus and no extra CO2 increased their growth rate by about 35 per cent. Increased CO2 will only make a difference to tree growth if we distribute fertiliser with it.
- It was warmer during the Mediaeval Warm period.
Palaeoclimate data [mostly proxy data from coral and tree records] shows warmer than average conditions, mostly in Europe and North America for at least some parts of AD 800-1200 — known as the Medieval Warm Period. But analysis of the data published in the journal Nature in July 2019 shows that:
- Firstly, that Earth wasn't uniformly warmed during that period. Peak warm periods occurred at different times in Europe than in North America. In other words, framing these localised temperature peaks as representing globally warmer conditions is misleading. "The a priori belief about a given palaeoclimate time series should be that it represents local information," the researchers said.
- Secondly, the research confirms that temperatures during the Medieval Warm Period weren't as warm as today. Instead, the researchers reiterated that the hottest period between AD 1 and AD 2000 was in the tail end of the 20th century, and that unlike between AD 800-1200, that warming has been uniform across 98 per cent of the globe at the same time. This also indicates that current CO2 climate forcing is stronger than the forcing between AD 800-1200.
The individual teams of researchers in the studies involved used seven different statistical techniques to reconstruct global temperatures during the so-called Common Era starting 2000 years ago and separately came to the conclusion that global heating in recent decades is of a pace and magnitude unique in at least the past two millennia, with human-caused climate change now "overwhelming" natural variability. They also studied variability over decades and centuries, including the Medieval Warming Period and the Little Ice Age, and found that no era had the spatial extent or intensity of the heating over recent decades.
- The world had been colder before when CO2 levels her higher.
Certainly CO2 has been at higher levels than today when temperatures were much cooler, but that was when things like low solar activity or Milankovitch cycles were the dominant climate forcings, or factors. There are a multitude of things that can affect the climate, and CO2 is just one of them. When all things are equal, and you take one factor and ramp it up or down, it's going to make a change.
We can observe this from the Pliocene epoch, a mere 5.3 to 2.6 million years ago. Background climate factors were similar to today, and like today, CO2 was around 400 parts per million. At the time, temperatures were about 3C to 4C warmer than today, sea levels were about 20 metres higher, and there were trees in Antarctica. See also above on the Ordovician era.
- Climate science is a conspiracy of the “elites”
Here, the contention is that there's a group of governments and global elites that stand to benefit from hoaxing the world into believing the climate is changing. It is alleged that these so-called elites conscripted groups including NASA, the Australian Bureau of Meteorology, the UK Met Office, the CIA, thousands of climate scientists and universities wordwide, among a raft of others, to contrive an environmental crisis. However, the reality is that not acting on climate change will punish the poor. The IPCC predicts millions will be displaced if warming hits 2 degrees.
Many of those will be in low-lying areas of developing nations including Bangladesh, and Australia's island neighbours in the South Pacific. Increases in extreme weather events also disproportionately affect areas with poor housing and infrastructure, and where subsistence farmers can be quickly undone by drought.
- CO2 has historically followed, not caused warming
It is true that CO2 has risen after the temperature has started going up, during some periods of warming throughout history, but the conclusion that therefore CO2 doesn't cause warming, isn't sound. There are in fact many forcings that cause climate change, and there are things called positive feedback loops.
So for instance, deglaciation that began around 20,000 years ago was initially caused by changes in Earth's orbit of the Sun. This initial temperature increase warmed the oceans, and warmer oceans, as research shows, release more CO2. That CO2 then increased in the atmosphere, and in turn created even more warming, that in turn released more CO2 from the oceans — a positive feedback, according to Professor Will Steffen and Annika Dean of the Australian National University and the Climate Council. "These positive carbon cycle feedbacks initially follow temperature rises, but then amplify them by causing further warming."
And CO2 isn't the only greenhouse gas that is involved. "Warmer temperatures can also melt permafrost [frozen subsoil] in the Arctic, causing the release of methane, a potent greenhouse gas," they said.
- Climate scientists contrive what they contrive for the money
The reality is that climate scientists don't earn any more than researchers in other areas, and science isn’t a particularly lucrative profession. "According to the ABS, people employed in full-time jobs related to professional, scientific and technical services earned an average of $1,872 per week in the year to November 2018. This is more than some industries, but less than some other industries, such as mining, which paid on average $2,696 per week to full-time employees over the same period."
On the other hand, the fossil fuel industry is worth nearly $5 trillion, according to a Bloomberg New Energy Finance report from 2014.
- Polar bear numbers are increasing, not decreasing
What do the figures actually say? According to a 2009 report by the IUCN Polar Bear Specialist Group, of the 19 recognised subpopulations of polar bears, 8 are in decline, 1 is increasing, 3 are stable and 7 don’t have enough data to draw any conclusions.
Estimates place the overall number of bears at about 20,000 to 25,000. Polar bears are classed as vulnerable by the World Conservation Union (IUCN) and listed as a threatened species under the US Endangered Species Act. The reason polar bears have been classed as threatened comes from the impacts of future climate change on the bears’ habitat. Current analysis of subpopulations where data is sufficient clearly shows that those subpopulations are mainly in decline. Further habitat degradation will increase the threats to polar bears.
- Another zombie myth and misleading claim:
The Australian Coalition Government inherited a 755 million tonne emissions "deficit" when it cam to power and that it has been turned around by 1.1 billion tonnes: https://www.abc.net.au/news/2019-10-24/zombie---angus-taylor-emissions-abatement-kyoto-protocol/11630780 See also https://www.abc.net.au/news/2019-04-11/fact-check-coalition-emissions-reduction-angus-taylor/10936652
[1] This section represents an edited version of portion of Chapter 4 of Sir John Houghton's Global Warming - The Complete Briefing, 5th edition, Cambridge University Press. 2015, pages 83-84.