Water is what sets us apart from the other planets in our solar system and it has existed on Earth for 3.8 billion years. It’s necessary for sustaining life on Earth and covers approximately 71% of its surface. Water exists in four environments on earth, which include the oceans, in the atmosphere, on land, and within living organisms. The majority of water on Earth, 97.25%, is found in the oceans, while only one thousandth of 1% exists as vapour in the atmosphere. Water also plays a crucial role in regulating the temperature of the planet through latent energy, which is released or absorbed when it transitions between liquid and gas.
The water cycle, also known as the hydrological cycle, is the continuous movement of water above and below the surface. The hydrological cycle is a closed system with four major processes: precipitation, surface runoff, evaporation and infiltration. It’s also an example of climate feedback, meaning that one change in the cycle leads to a cascade of events that can result in either positive or negative changes.
On Earth, we have two water cycles: small and large. The large water cycle is made up of the cyclic phases of rainfall and evaporation. Once rainfall makes contact with the Earth’s surface, it’s absorbed by the cracks, pores and crevices of underground rocks and soil to become groundwater, or humans, plants and animals capture it for use. It may also flow as run-off, which enters rivers, streams and lakes. Much of the run-off flows connect to the ocean and the cycle is repeated.
The small water cycle is more of a local transfer of water, taking place within the large water cycle. It’s a closed-loop circulation of water, which is evaporated on land in the form of precipitation. There is also a small water cycle that occurs over the seas and oceans, but the key role of the small water cycle is that it keeps water within the same region.
Graham, S., Parkinson, C. and Chahine, M., 2010. The Water Cycle. [online] NASA Earth Observatory. Available at: https://earthobservatory.nasa.gov/features/Water
Scientists have concluded that impacts from climate change and feedback loops are altering the water cycles. As extreme temperatures become more frequent, the average global temperatures rise and are likely to cause parts of the water cycle to speed up. For example, evaporation rates will increase worldwide, as warmer air can hold more vapour. Drier climates will get drier, while wetter climates experience more rain.
With a reduced small water cycle, and consequently decreased vegetation and increased desertification, more energy is converted to sensible heat, and the cycle is amplified. More extreme weather events are occurring as a result, thus changing the climate.
In Australia, it is evident that droughts are becoming more likely, severe and prolonged due to drier and hotter conditions associated with climate change. This has led to a decline in soil moisture as a result of increased water loss from plants and soil. The hotter and drier conditions have meant there has been less runoff into streams, rivers, lakes and dams, particularly in the southwest and southeast regions of Australia. This severely impacts Australia’s water security, and increases crop failure and livestock deaths, leading to an impact on the Australian economy.
However, despite these impacts, there is still hope – as long as we sustain small water cycles at the regional level. The small water cycle must be utilised, before the rainfall rates decline further and it becomes much more difficult to retain water within the Australian landscape. The more water within the small water cycle, the more efficient it is.
One way to measure the efficiency of the water cycle is by looking at the occurrence of dew. Dew is a measure of surface moisture and shows that transpiration is occurring in the daily water cycle and is being recycled. Increased dew indicates that plants are photosynthesising, and that water is being used to cool the plant during its growth. As dew increases, the growth of the plants increase, and thus can be used to measure the strength of the water cycle.
Another way of measuring the efficiency of the water cycle is by looking at how resilient the landscape of a given region is. This includes indicators such as producing a high crop yield and steady streamflows. Without an efficient water cycle, these would not be possible. Landscape resilience can include how likely the landscape is to survive a fire and recover, how it copes in times of decreased rainfall, or increased flood events. The healthier the landscape, the better equipped it is to combat the impacts of climate change.
Given this information, it is clear that rehydrating Australia is vital in restoring the landscape. Drainage and land clearing has led to an inefficient water cycles and the loss of functional vegetation. That’s why it’s so important that we focus our efforts on landscape regeneration. Not only to protect our land from being degraded where it can no longer be used for farming, but to support the efficiency of the water cycle on a regional basis.
It appears we have the ability to influence the water cycle by adopting a natural systems approach – and we know that it operated efficiently until mankind settled in Australia. If we can influence small water cycles and make them more efficient on a large scale, we may have the ability to curb some of the impacts from climate change and challenges such as prolonged droughts.
One way we can alter small water cycles is by starting with individual farms, which often have a lot of land area. Martin Royds, a fifth generation beef cattle farmer from Braidwood, New South Wales, used a natural systems approach to manage his farm – enabling nature to operate as it did in the past.
His approach to slowing the flow of the water, while rehydrating the land, allowed for more efficient use of water on his property. He also adopted rotational grazing and other soil carbon techniques, which enabled him to be the only farmer to have access to enough water to fight off the recent fires. He attributes his success to his natural systems approach to farming and land management – without it, his farms would be in a different place today.
Through this natural approach, Martin was also able to feed his livestock during droughts whilst others in the region struggled to keep their livestock alive. Martin also ensured he had a significant amount of biomass covering his land – including over 80 species of grass and plants to ensure resiliency – which has also helped keep his property hydrated.
It’s essential to support the regeneration and hydration of landscapes so that we can mitigate climate risk and bolster our resilience. This is critical, especially for Australia, given the desertification of our land, as well as reduced biodiversity and depleted soils. Decades of poor farming practices, coupled with low vapour levels and extreme weather events, have led us to a climate emergency.
Nature-based solutions are emerging as a top priority for meeting greenhouse gas targets and have been highlighted as one of the primary solutions for combating climate change. Nature-based solutions can provide at least one-third of the strategies needed for climate change mitigation, but currently receive less than 3% of the funding. There is a dire need to invest more into this industry – not only for our local communities, but also for the country – and the planet.
If you’re an investor that’s interested in land restoration and climate resiliency, please contact Jennifer Lauber Patterson to discuss how to get involved.