The law and science have not always had much to do with each other, but more recently have begun to intersect. A very obvious current example is the intertwining of medical science and the law around the issue of compulsory Covid vaccinations.

However recently a rather less visible intersection has become evident to lawyers: that of climate change and property transactions. This is not mainly (or even largely) been because of the obvious issue of the value impact on coastal properties threatened by beach erosion. Its impact is now clear in relation to regional and rural properties, where value resides not simply in the land, improvements and location; but very importantly the income-producing potential of the properties, and the potential impact of extreme weather. In other words, the effect of climate change.

Scepticism about climate change is understandable because the links between the causes, as scientifically assessed, and the observable effects, aren't obvious. But lawyers now need to be able to advise clients about the future risks in property transactions, so it's necessary to gain a better understanding.

Climate change scepticism

One of the reasons why scepticism about climate change flourishes may be because there is little explanation of the underlying concepts, many of which have been uncontroversially established for centuries.

The underlying mechanisms of climate change have been proved and can be experimentally verified; even if it can be difficult to identify and quantify specific outcomes. The first part of this article takes a look at those mechanisms.

Some of these underlying concepts which are often unexplained are things about which there should be no argument - the second law of thermodynamics, electromagnetic radiation, the heating and cooling of the ground, the greenhouse effect and human-caused warming. It then discusses things which could be subject to debate - chaos theory and the misuse of statistics.

The second part of this article looks at the many challenges facing Australian property owners and developers as vendors and purchasers of real estate impacted by climate change.

Second law of thermodynamics

There are all sorts of ways of stating the second law of thermodynamics, but as good as any is that all physical systems tend toward states of minimum energy. "Entropy" is a word used to describe a state of maximum disorganisation, because energy is required to keep things in some kind of orderly fashion, and this tendency is irreversible in direction: no physical system ever by itself moves in the opposite direction.

A common nineteenth century example ran as follows: if you heat up a cannonball in a fire and then drop it into a barrel of cold water, what happens (apart from a lot of popping and fizzing) is that the cannonball cools and the water heats up, until everything is at the same temperature.

Everyone knows from their own experience that this is true. If you put your cup of hot coffee on your desk and are then called away, when you get back after a sufficiently long time the coffee will be at room temperature. In the process the air in the office will theoretically have warmed a trifle, but even if the office were sealed there would be no practical means of measuring the tiny change.

Electromagnetic radiation

One of the fundamental forces in the universe is electromagnetism. There is a wide range of frequencies, but the relevant bit is visible light and the frequencies either side of it.

On the violet side of the visible spectrum is ultraviolet light. It is shorter in wavelength, and higher in frequency, than visible light. Beyond that are microwaves and X-rays. The shorter the wavelength and the higher the frequency, the more energy. UV radiation inflicts sunburn; X-rays serious damage.

Beyond the red end is infrared radiation: longer in wavelength and lower in frequency. The heat you feel from oil heaters is infrared radiation.

If you took the cannonball out of the barrel when the water had just stopped boiling, it would radiate heat which you could feel but not see. This is infrared radiation, and the physicists call a source of this kind a "black body radiator", meaning simply that it's not incandescent.

Heating and cooling of the ground

The sun is a nuclear fusion reactor. It operates at about 6000 degrees Celsius: seriously incandescent. The radiation from the sun is high energy ultraviolet. Because of its short wavelength and high frequency, it passes for the most part straight through the atmosphere without being absorbed by anything. The exception is ozone (O3), which absorbs some UV; hence the concerns about "holes in the ozone layer".

However, when the UV radiation strikes the surface of the earth, it is eventually absorbed by the soil, which is thus heated up. Because the radiation has passed through the atmosphere unabsorbed, the atmosphere has not warmed up or, more accurately, has not been warmed by the sun.

When the sun goes down, the ground is hotter than the atmosphere. By the second law of thermodynamics, it starts radiating energy back into the now cooler atmosphere. Like the cannonball in the previous example, the ground is a black body radiator, and the radiation it emits is infrared radiation.

The greenhouse effect - a key point for the sceptics

While apart from ozone there are no gases in the atmosphere which in any way block UV radiation, there are some which will absorb infrared radiation. Water vapour and nitrous oxide (N2O) are two, but the ones which count are carbon dioxide (CO2) and methane (CH4). These can absorb infrared radiation.

The key thing is that molecules of greenhouse gases store some of the energy emitted by the ground as it cools. Thus the system is not a zero-sum system: more energy has been received than has been emitted. This is the underlying mechanism of global warming.

The key take-home message for the sceptics - the "science isn't in yet" crowd - is that, if you go to the trouble of demonstrating this experimentally, the effect will be replicated 100% - not 95% or 99% - of the time. In the process of scientific inquiry, showing that something happens 95% of the time is pretty good evidence, even if (as often happens) no-one can actually explain why it happens.

Here, in addition to knowing that the effect happens 100% of the time, we know exactly how and why it happens. We can measure radiation frequency and wavelength. We can measure bond energies in molecules. We know how greenhouse gas molecules absorb the infrared radiation. And we can express all this mathematically.

Human-caused warming

One thing about which there should be no argument (although there often is) is the role of humanity in creating climate change.

Humans have smelted metals for thousands of years, but only since the 19th century have they done this on a massive scale. The Industrial Revolution, bringing with it bridges and battleships made of iron and steel, saw CO2 emissions increase exponentially.

Methane from agriculture is a non-trivial contributor, but the single statistic which should put the issue beyond doubt is CO2 emissions from 1800 to the present.

Seeds of doubt - chaos theory

Newtonian physics had it that every physical system is 100% predictable, and the reason it appears otherwise is that our experiments can't be sufficiently controlled or accurate. While Einstein showed that physical systems did not follow Newtonian rules at extremes of scale (galaxies, and the subatomic world) he did not doubt the soundness of the Newtonian rules in day-to-day, Earthly, settings.

However it's now accepted that Newtonian predictability is also a bit of a myth. While it is not possible to have a full discussion of chaos theory here, you have probably heard of the Butterfly Effect (associated with the 1970s work of physicist Edward Lorenz), which is an aspect of it.

The Earth's atmosphere is a closed system - if it weren't, all the atmosphere would have drifted off into space billions of years ago and the population would just be anaerobic bacteria.

However, it's an enormously complex closed system, and identifying cause and effect incredibly difficult. Chaos theory backs that up.

It's why even the most committed disciples of global warming acknowledge that a particular flood or bushfire can't be attributed to a particular event.

Seeds of doubt - misuse of statistics

Benjamin Disraeli famously talked about lies, damn lies, and statistics. People can make statistics say anything they want. There are more polar bears in downtown Nome now than ten years ago, so the planet is cooling, not warming.

The magic incantation "statistics show that" preceding any crazy proposition you choose, will have some of the populace believing it. Even in a far less chaotic system than the Earth's atmosphere, statistics only have validity if the methods comply with clear mathematical parameters. Which usually isn't the case.

Climate change, fossil fuels and risk

The only possible rational approach is to treat climate change as a matter of risk. The standard risk matrix plots likelihood of an event against the impact of its occurrence. With properly used statistics, it should be clear that serious harm from global warming is very likely; maybe inevitable in the absence of action.

But even if you doubted this, even a decent possibility that the predictions are accurate should dictate the taking of action, because of the catastrophic nature of the events if they do occur.

Second, even if you didn't believe this at all, fossil fuels are finite. Coal seams aren't being renewed. Burning fossil fuels generates pollution in both air and water. So moving to renewables seems pretty much a no-brainer, however much you do or don't accept the human causes of climate change.

Impact of climate change in Australia

Climate change in Australia has been a critical issue since the beginning of the twenty first century, with rising CO2 levels warming the planet and exposing people to increasing health risks.

It is generally accepted that Australia is becoming hotter and more prone to extreme heat, bushfires, droughts, floods and longer fire seasons because of climate change.

Since the beginning of the twentieth century, Australia has experienced an increase of one degree Celsius in average annual temperatures. Global warming has increased at twice the rate over the past 50 years than in the previous 50 years.

Recent climate events such as extremely high temperatures, bushfires, widespread drought and flooding have focused government and public attention on the impacts of climate change in this country.

Rainfall in south west Australia has decreased by 10-20% since the 1970s. South east Australia has also experienced a moderate decline since the 1990s. Rainfall is expected to become heavier and more infrequent, as well as more common in summer rather than in winter.

Water sources in the south east areas of Australia have depleted due to increasing population in urban areas, coupled with persistent prolonged drought. While there are short-term fluctuations, water supplies overall are dwindling.

Bushfires have become more widespread, intense and life threatening in the past few years. Storm activity has also increased, sometimes leading to hail damage, tornados and flooding.

The year 2019 was Australia's warmest on record, with the annual national mean temperature 1.52 °C above average, surpassing the previous record of +1.33 °C in 2013.

Beyond question, climate change is having an impact on property transactions in Australia. There are many challenges facing property owners and developers today as vendors and purchasers of real estate impacted by climate change.

Rising sea levels and erosion of coastal properties

An obvious and much publicised impact of climate change is the rising sea levels along the coastline of Australia. This is dramatically seen along the northern beaches of Sydney, where property boundaries have been eroded by wave action along the coastline north of Sydney.

Registered surveyed title boundaries have been washed away and improvements damaged and destroyed. Property owners cannot convey the registered title of their property.

Bushfire risk, zoning and development

Property adjacent to bushland is prone to a higher bushfire risk and may be subject to zoning restrictions. The level of bushfire risk affects development requirements - the higher the risk, the more protection you need. The term "Bushfire Attack Level", or BAL, is used to quantify this risk.

The level of bushfire risk is affected by location, the nature of vegetation, the distance from the vegetation to property, and the nature of the surrounding terrain, and the extent to which that might intensify fire. As part of the build process, you will need to confirm your BAL in a written report. The NSW RFS can help with this step.

There are six bush fire attack levels. BAL-Low is the lowest bush fire risk and Flame Zone is the highest.

Multiple factors create increased insurance risk

Rising sea levels, flooding and bush fire risk also impact on insurance risk. Affected properties may be uninsurable or may become uninsurable because of changing risk analysis or planning regulations.

There is anecdotal evidence that some insurance companies are refusing to offer property insurance in villages and towns surrounded by bushland. This may affect properties in the Blue Mountains, on the central coast, in the far northern suburbs of Sydney and the western districts of NSW, west of Tamworth.

Increased pressure on limited water resources

Water resources and storage are also impacted by climate. Rising population and increasing demand for agricultural products, both food and fibre, are putting pressure on limited water resources.

Surface and ground water resources are under increasing stress. Water allocations have been limited under the Murray Darling Basin Plan as more water is allocated to rivers and the environment. Water prices are rising. Agricultural land with access to water is increasing in value.

Depletion of soil moisture due to rising temperatures

Rising temperatures also deplete soil moisture and exacerbate severe drought conditions across southeast Australia. Declining soil moisture affects farm productivity and may reduce farmland prices.

While there has been an increase in soil moisture in the western districts of NSW in the last two years due to good rainfall, the long-term trend is a decline in soil moisture, particularly in the subsoil.

This has an impact on land use, such as grazing and crop growing. In some areas wheat and barley are no longer viable crops, while in others farmers struggle to graze cattle, for example, on land which is now barely suitable for this purpose.

Transition to alternative power sources can create opportunities

Notwithstanding the challenges, there are opportunities.

Harnessing energy which does not create greenhouse gas emissions from fossil fuels will reduce CO2 and some types of air pollution.

With a lower level of emissions we can moderate the greenhouse effect and improve the quality of the air we breathe. Nitrous oxide, carbon dioxide and sulphur dioxide released by fossils fuels pose risks to health if inhaled over time.

Cleaner air can help to save lives, especially when it comes to illnesses such as lung disease, heart disease, respiratory conditions and even some cancers.

Benefits of alternative energy sources

The installation of solar panels and storage batteries may add to the value of residential, commercial and farming properties and reduce energy dependence.

Alternative energy costs will fall as new power sources develop and new supply infrastructure comes online.

Diversifying energy supply reduces dependence on imported fuels.

The transition from fossil fuels to alternative energy will create economic development and jobs in manufacturing, installation and infrastructure construction.

Importance of good land management practices for agriculture

For Australian agriculture, adaptation and land management practices will play an important role in building resilience and mitigating the physical impacts of climate change.

Water and soil conservation may improve water retention, soil quality and increase land values.

Tree conservation and carbon sequestration may also result in financial opportunities, including carbon credits that also provide environmental benefits while improving productivity, increasing resilience to a changing climate and preserving or improving property values.

Everyone stands to gain from understanding climate change

All of the improvements which can be made have economic and health benefits. Buyers of agricultural land, in particular, can achieve a higher level of certainty as to the longer term value of the property they are buying.

Lawyers acting in land transactions have long been disciplined in "searching" the qualities of the property for things such as easements, encumbrances, planned developments and the like; things which affect future property values. To this we can now add the effects of climate change.

Scepticism may fade when the hip pocket is hit by the impacts of climate change. However it isn't all that hard to understand the underlying science, and dealings with which lawyers help their clients should be more smooth and effective where there is better understanding of the factors affecting risk.

Geoff Baldwin
Michael McHugh
Buying a rural property
Stacks Law Firm

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.