The Queensland floods of 2010–2011 raised a hard question: was this simply another natural flood, or a sign of a changing climate? From personal experience near Bundaberg, this article explores how extra greenhouse energy can amplify flood and drought cycles even before average temperatures rise much. It also argues that the best near-term response is practical: change agriculture so it absorbs carbon, improves soils, and reduces vulnerability to extreme rain and drought.
Colin Austin — 19 January 2011 — Gin Gin, near Bundaberg, Queensland
We can mitigate the flood and drought cycle by simple changes to our agricultural system.
When the Floods Came
For three days I have been digging a mega trench around my house to divert the water running under my house.
As I live near Bundaberg I am used to floods. Once or twice a year we will get a major rain dropping over 200 mm in two or three days. The water forms a sheet, flooding the roads, but when the rain stops the roads clear, the sun comes out, and all is well again. It is not really a big problem. After months of “hot and dry” the rains are almost welcome.
But these rains were very different. It was not just one storm but storm after storm after storm, saturating the ground so the full force of the rain ended up as run-off. We were cut off for several days with no way of communicating with the outside world.
Damage estimates kept going up daily. The latest estimate I saw was $40 billion, with deaths and much personal hardship.
And it is not just Queensland. Throughout the world—Brazil, Sri Lanka, the Philippines, the Rhine, the UK, Pakistan, Russia and the Rhine again—are just examples of severe flood and drought damage.
Future Food Production
My interest is in developing technology to secure future food production. Increasing population and degradation of our soil are part of the picture, but adapting agriculture to climate change is a critical part of this work.
I had many experiments under way on different ways to grow food. It was very upsetting to see these experiments disappear under water. A short flooding has little effect—the plants will soon recover. The extended flooding, as we have just experienced, does the damage. For commercial farmers this is their livelihood vanishing into the murky waters.
Is this just a one-off freak flood or is it an indicator for the future? This is a critical question, not just for me but for everyone. I had to find the answer.
When the internet returned after the floods, I resolved to do further research to look for answers.
Floods — Freak Weather or Climate Change?
I was in for a surprise. At first there were few postings, but then the avalanche started—a veritable cyber war.
There are literally hundreds of climate change research centres around the world. They agree on the basic mechanics of the greenhouse effect and that temperatures will rise by between 2 and 5 degrees in some fifty years. They also agree climate change will lead to more wild weather and amplified flood and drought cycles, although they are cautious about relating it to any specific weather event.
But just as there is broad agreement among climate experts, there is an equally violent reaction from the skeptics. Their main argument is that flood and drought cycles are normal and there is nothing exceptional about the current floods. They point to even higher flood levels in the 1840 and 1893 events. One claim is that the devastation of the current floods is the result of bad water management and the poorly regulated housing boom.
Of course climate experts have never said the flood and drought cycle is “caused” by climate change, but that the natural cycle will be amplified by the extra energy in the system.
I also noticed there is an enormous range of literature—from kids’ booklets to sophisticated papers—explaining the mechanics of climate change. How had all of us involved in climate change been doing so badly in presenting our case? We had obviously got something seriously wrong. But what?
The third aspect of the debate is what we should do about it, and this is sadly neglected.
Progress on climate change had virtually stalled for the last five years. Why? Naomi Oreskes’ book Merchants of Doubt throws light on how effective destabilising strategies can be. But there is more to it than vested interests holding up change. There is a significant proportion of the population opposed to action. I can understand that attitude from my experience in pioneering computer simulation.
Reasons for Dissent
If there is so much agreement among climate change researchers, why is there so much dissent?
What climate experts say and what the public hears are very different. Look at the message being received: “We need to cut emissions or in fifty years we will experience a temperature rise of between 2 and 5 degrees.”
That may be true as a scientific statement, but how does the public react? Many say: “Fifty years is a long time. Think of the technologies that have developed since then: the jumbo jet, the computer, the internet, the mobile phone. It is a reasonable bet that in the next fifty years some new technology will emerge to combat global warming.”
They also say: “What is the big deal about a couple of degrees temperature rise? Most of that will occur near the polar regions, so it might be good rather than bad. And for all this you expect us to give up the benefits of modern living—my car, air conditioning, and so on. It is not worth it. Thanks but no thanks. I will wait and see.”
In other words, they are saying it is not worth making major changes now for possible negatives far down the track. Timing is the issue.
This attitude could shift if it was clearer that climate change is already influencing floods and drought. But the debate has been damaged at both ends. Overzealous converts preaching an impending Armageddon also prevent progress. The world is not going to fry up in a little ball.
Meanwhile, simple steps to change agriculture could immediately start extracting carbon from the atmosphere. This is not even a long-term “cost” if it safeguards future food supply. Yet conflict between skeptics and zealots stops pragmatic steps that should be widely acceptable.
Now Is the Time
Think about all the people in Toowoomba, Brisbane, Rockhampton and now Victoria who have been flooded. Think about the people around the world who have suffered from floods in Pakistan, Brazil, Sri Lanka, the Philippines, the UK along the Rhine, together with those who have suffered from bushfires or drought in the US, Russia, Africa as well as Australia.
Their problems are now, not in the dim and distant future. They are looking for protection now.
Reference: Interpreting_the_data shows unequivocally that temperatures are rising. Yet many skeptics and much of the public decide temperature change is relatively unimportant and anyway a long way into the future—so why worry now, something will turn up.
Presenting climate change as a small rise in temperature at some point in the future is not effective. We have to relate climate change to what is happening now: the flood and drought cycle and the threat to our food supplies.
Climate Change and the Flood–Drought Cycle
Greenhouse gases increase the energy being trapped by the earth. It takes time for the mass of the earth to show even a small temperature rise. This is why climate change is often thought of as a long-term issue.
Weather, however, is a local instability. It is not the same as climate. It is caused largely by differential heating of the atmosphere: some areas are heated faster than others, creating temperature and pressure gradients. These gradients cause winds, which can be dry or wet depending on whether the moving air is cooling or heating.
Increasing greenhouse gases means greater energy input. That, in turn, produces greater variation in temperature and pressure. In plain language, the weather becomes wilder.
The effect of extra energy is immediate. This is why we are experiencing floods and drought around the world even though the temperature increase is still relatively small.
We cannot procrastinate about a distant global temperature rise. We are dealing with the here and now. Data indicates that flood and drought rainfall cycles are becoming more severe.
Action on Climate Change
Despite all the talk and debate about the floods (there were over a million hits on “Queensland + flood + climate change” on Google at the time), there was virtually no discussion on what to do about it.
We need pragmatic solutions. This is not the time for denial or Armageddon prophecies of doom. It is a process of analysing problems and coming up with solutions that work, are affordable, and acceptable to the population.
There are many facets to the problem: damage to property, infrastructure and agricultural land. Food production is, or will be, probably the most severe problem globally. It is also the source of a solution.
Burning fossil fuels is blamed as the number one cause of climate change. Around the world there is widespread resistance to foregoing the benefits of modern industrial society. Developing countries have even greater incentive and justification to adopt modern technology to alleviate poverty.
No doubt new technologies will evolve enabling us to maintain affluence without carbon emissions, but this will take time. We need a solution now.
Science, Engineering, and Acting Without Perfect Certainty
Climate science is a science. The aim of science is understanding based on facts. Climate scientists are understandably frustrated that they cannot give an unambiguous answer linking a specific flood or drought to climate change. Scientists do not like errors.
Errors are the tools of trade of engineers. Engineers are used to errors and know how to handle them. The key tool is the use of “safety factors”. Safety factors are really ignorance factors: a way of making things work when you do not have all the answers.
Flood and drought, with all the damage they cause and the threat to our food supply, are too important to wait until we know every connection between climate change and weather extremes. We need the engineer’s pragmatic approach and skills in handling uncertainty.
There is an old adage: a scientist looks at what is and says “why”; an engineer looks at what is not and says “why not”.
There are actions we can take right now. The short-term solution lies in changing agriculture on a large scale. It is not widely recognised that current agricultural techniques are major emitters of carbon, yet modified agricultural practices can absorb large amounts of carbon. Changing agricultural technology can make food production more sustainable and less prone to damage from flood and drought.
The Technical Solution: Soil as a Carbon Tool
My interest is how to change agriculture to both mitigate and adapt to climate change. I have been developing technologies that take carbon from the atmosphere and embed it in the soil. This is research I have conducted for some thirty-five years, and I know that for a period of at least twenty years we can stabilise carbon levels in the atmosphere.
Plants are already absorbing some thirty times all man-made emissions. This is an important but little appreciated fact. The problem is that most of this carbon goes straight back into the atmosphere and does little to reduce atmospheric carbon.
However, it is relatively straightforward and inexpensive to divert part of this return flow of carbon—using allies such as mycorrhizal fungi—to embed carbon into the soil. This improves agricultural output and makes food production more sustainable.
Whether we can do this for longer than twenty years is unknown at the moment. But a twenty-year window gives us time to find out whether the period can be extended, or to develop alternative technologies.
This will not happen by itself. It needs a plan and acceptance of certain realities. The immediate problem is that, in the short term, it costs the farmer money to change practices so more carbon is absorbed into the soil.
Carbon Trading and International Cooperation
A carbon trading scheme—particularly one in which rich countries offset emissions by buying carbon credits from developing countries—would solve the farmer’s cost problem and could have major social benefits.
This cannot be done by Australia in isolation. We are a relatively small contributor to greenhouse gases and have limited capacity to absorb global carbon. We need cooperation from major developing and agricultural nations such as China, India, Brazil, Russia and others. If we cooperate broadly, we can hold the carbon battle.
This requires government initiative: establishing scientifically monitored trials, and negotiating with other countries on effective carbon monitoring and trading.
Other countries have every reason to cooperate. It provides protection against flood and drought cycles. For developing countries it provides a way to upgrade food production capacity and ward off famine. For developed countries it provides a source of carbon credits unlikely to be available in their own landscapes.
Public Awareness: Changing the Message
Climate action requires public support, but most people are not concerned about a few degrees rise in temperature fifty years ahead. It is not on the daily agenda of most households.
Skeptics promote that framing, and it lands on willing ears in a public reluctant to give up modern luxuries. Meanwhile, dedicated supporters sometimes create an impression of impending Armageddon that can only be resolved by draconian measures. While well intentioned, this can also reduce support for action.
The first part of the action plan is to get the message out that floods and drought are amplified by climate change, that this is an issue to address now, and that practical solutions are available right now.
Links and Supporting Notes
Mechanics of Climate Change
Fourier did the first heat balance on the earth over 200 years ago. The first detailed prediction of global warming was carried out by Arrhenius over 100 years ago—done by old fashioned paper and pencil. He came to the same basic answer our high-tech computers reach. There is nothing mystical here.
This is not based on “hyper technology”. When light of a certain wavelength passes through a gas, some energy passes through, some is absorbed, and some is bounced back. The ratios can be measured by apparatus developed over 150 years ago.
In the same way, when light lands on the surface of the earth, some energy is absorbed and the balance is reflected back at different wavelengths. This is simple physics accepted for hundreds of years.
Pioneering Computer Simulation
If climate change physics is simple and accepted, why do intelligent people reject it? This question is more about how people think than about the physics itself. To answer it, I go back to my early experience of developing computer simulation.
My simulations had nothing to do with climate change. They solved an engineering problem: hot plastic flowing into a cold mould. The problem required solving fluid flow and heat transfer equations, complicated by viscosity changes with temperature, flow rate and pressure.
This may sound complex, but the physics itself is made of simple laws—essentially Newton’s laws of motion and heat transfer—taught in early school science. Just like climate change.
The difficulty was the combined complexity. During development I checked, by old fashioned hand calculations, every single calculation done by the computer. Nothing flash about this; any competent student could do it now. The real problem, like climate change, is that the system is too complex to include every factor. You must decide what matters and what can be safely ignored.
For at least six years I presented this technology and was grilled by academics on what factors my simulation included. I was denounced if I had ignored some technical point. The attitude was that simulation was not valid unless every aspect was included—perfection was the only standard.
Industry took a very different view. Engineers had a big problem costing time and money. They wanted any solution—even imperfect—that worked reasonably well. They had a vested interest in it working, and they were willing to set up trials.
I used to tell a story about two hikers chased by a grizzly bear. One stopped to change into running gear. His mate said, “Even in running gear you cannot outrun a grizzly.” He replied, “I don’t have to. I just have to outrun you.”
The moral is practical: engineers with a real problem wanted to believe a working solution could help. Likewise, with climate change we do not need absolute proof on every linkage before acting. Our floods and droughts show we must focus resources on practical solutions now.
Interpreting the Data
Can we do better in interpreting available data? Consider a graph of flood levels in the Brisbane River floods. This type of graph is used by skeptics to argue flooding is a natural freak event unrelated to climate change. At first glance it looks convincing: the floods in the 1800s were very large, and in the age of the horse and sailing ship they were not caused by modern emissions.
It is true that in Australia (and worldwide) freak floods occur on what appears to be a random basis. Some skeptics also use graphs—sometimes selectively chosen—to appear to show a fall in temperature and deny warming.
No one denies the weather is cyclic. BOM graphs show temperature goes up and down. It is easy to pick a short period on a selected part of a graph and give a false impression.
There is no dispute that floods and droughts are natural events. The question is: does climate change make these floods more severe or frequent?
If we look at sea surface temperature, which is more stable, over a long period, there is no serious issue that temperature has been steadily rising.
Energy and Temperature
Greenhouse gases do not immediately lead to an increase in temperature. They immediately increase the rate of energy input to the earth, which over time leads to a new equilibrium temperature. That equilibrium rise is small compared to normal daily and seasonal cycles. It is therefore unconvincing to many people that a small rise in equilibrium temperature, by itself, is catastrophic—especially if it appears far away in time.
Energy is different. It happens right away and the results can be dramatic. Greenhouse gases do not cause uniform heating of the earth. Some areas heat faster than others, creating increased temperature and pressure gradients around the globe. This is the cause of wild weather. The larger variations in energy input are the real problem, not simply the average temperature increase.
The best analogy I can think of is heating water. Heat a cup of water in a microwave and there is little movement; it warms more uniformly until near boiling (and can become explosive if it boils together). Boil water over a gas flame and the heat is local; the water becomes turbulent, and the faster you heat it the more turbulent it gets. That turbulence is a useful picture for what happens when the climate system gains extra energy unevenly.
Analysing Rainfall Data
I have shown how easy it is to “fiddle” presentation even with a clear variable like temperature. Rainfall and drought are far less clear cut. Mathematical techniques designed to present data more meaningfully—moving averages and statistical manipulation—can mask real signals. You end up with nice smooth curves and tidy parameters, but part of the truth is hidden.
While we wait for someone to develop better mathematics for this problem, we must use tools available now. Humans are bad at interpreting tables of numbers. We do better with graphs, but still not as well as we could. We are astonishingly good at recognising patterns and shapes—faces, for example—even among thousands, and even more so when movement patterns are involved.
I tried applying this to BOM graphs. Take Queensland rainfall since 1900. A static graph with a five-year floating average still makes pattern recognition difficult. I made this into a short video to help interpretation.
References mentioned: qldrainfall.jpg; queenslandrain.mp4 (media referenced in original; no media included here)
If we include the floods in 1840 and 1893 there are six rainfall peaks. Our eyes are drawn to peaks, but mathematical pattern is hard to see, other than that most peaks occurred since 1950, with the first half of last century being relatively flat. The five-year average does not show a dramatic increase or decrease in total rainfall.
However, if we look for pattern, we see that in the first half of last century there was a clear flood and drought cycle with a short frequency of around three years. More recent cycles appear longer—up to ten years—with a tendency for rainfall to build up incrementally to a major rain event, then drop back sharply, then build again over years to the next major event.
Colin Austin — © Creative Commons. Reproduction allowed with source acknowledgment; commercial use requires a license.
