Andreas Chai, Griffith UniversityLast month’s dire report by the Intergovernmental Panel on Climate Change may have left you feeling overwhelmed, or unsure what to do next. We often hear about ways everyday people can tackle climate change, but which acts will make the biggest difference?
The academic literature tells us three spheres of our lives contribute most to climate change: home energy use, transport, and food consumption. Together, these activities comprise about 85% of a household’s carbon footprint.
As one study showed, by adopting readily available practices, households in developed countries can cut their carbon footprint by 25% with little or no reduction in well-being.
Clearly, national governments must set, and meet, ambitious emissions-reduction targets. But 72% of global greenhouse gas emissions are related to household consumption. So small changes at the household level really can make a world of difference. Here’s a guide to get you on the right path.
Using energy in the home more efficiently is a good way to reduce your impact on the climate. Signing up to so-called “demand response” programs is a relatively new way to do this.
Demand response involves making changes to energy use to reduce stress on the electricity grid during times of high demand. In Australia, this often entails electricity companies offering financial incentives to households so they use less energy at peak times.
For example in Queensland, the state-owned company Energex offers up to A$400 to those who install a “PeakSmart” air conditioner. When the electricity system is under stress, the electricity network will remotely switch the air-conditioner into a lower performance mode.
Energy retailers have also been trialling demand response programs in other states. For example under AGL’s Peak Energy Rewards program, customers can choose to receive an SMS message prompting them to reduce their energy use at peak times. By turning up the temperature on the air conditioning or waiting to do the laundry, people can earn discounts on their energy bills.
Demand response leads to less electricity use and reduces the need for fossil-fuel electricity generation at times of high demand – and so, can cut greenhouse gas emissions in the electricity sector.
If you drive a traditional petrol or diesel vehicle, try to reduce the amount of time your engine idles. Research last year found Australian motorists are likely to idle more than 20% of the time they’re driving. If idling was eliminated from all journeys, the emissions saved would equal that of removing up to 1.6 million cars from the road.
While some idling is unavoidable such as when stopped at traffic lights, drivers can turn their engines off while parked and waiting in their vehicle.
And drive smoothly, not aggressively. Driving with limited acceleration and braking has been found to significantly reduce emissions.
You might be thinking of making your next car an electric vehicle. While the cost of electric vehicles has traditionally been prohibitive for many people, the technology is expected to reach price parity with conventional cars in Australia in the next few years. And these days, you can even get a good second-hand deal.
There’s a lot of misinformation out there about whether electric cars are a good choice for the planet. So where does the truth lie?
It’s true that electricity used to charge an electric vehicle’s battery is often sourced from fossil fuels. And energy is still required to make an electric vehicle – in particular, the battery.
However, last year, research found in 95% of the world, electric vehicles were less emissions-intensive than traditional cars over their full life cycle – even accounting for the current emissions intensity of electricity generation.
If you buy an electric vehicle, it’s important to ensure potential emissions savings are realised. One way of doing this is by recharging during the middle of the day when renewable electricty is most abundant. And don’t forget, as renewable energy forms an ever-increasing share of the electricity mix, the climate benefits of electric vehicles become even greater.
And of course, don’t forget about the obvious low- or zero-emission ways to get around: walking, cycling, catching public transport and car pooling.
Research earlier this year showed food systems are responsible for a third of human-caused greenhouse gas emissions. And recent studies show even if the world stopped burning fossil fuels immediately, emissions from the global food system could still push global temperatures over the 1.5℃ warming threshold.
Reducing meat consumption is a well-known way to cut your carbon footprint. In fact, recent research from Sweden showed just how high emissions from meat and dairy products are, compared with substitute products. It found:
- lamb is 25 times more polluting than tofu
- milk is five times as polluting as oat drink
- dairy-based cheese is four times as polluting as vegan cheese.
In Australia, the range of meat alternatives is growing quickly. In just one example, Sydney-based All G Foods is developing plant-based mince, sausages, chicken and bacon, as well as “cow-free” dairy products. Helped along by $5 million in federal government funding, the company’s first product launches this month.
Another food that promises to help cut your carbon footprint is seaweed. Australia is only just catching on to the benefits of commercial seaweed production, which can be grown with few environmental costs.
Australia’s first factory manufacturing food-grade seaweed products opened in New South Wales last year. It has the capacity to put seaweed into pastas, and even muesli!
Reduce, reuse, inspire
Reducing your climate footprint is not just about buying “green” stuff: it’s also about avoiding consumption in the first place. So try to buy less – and if you can’t avoid it, try and buy second-hand.
You never know, you might start a revolution. Evidence suggests people who observe their peers undertaking environmentally friendly behaviour often adopt similar actions.
Gregory Moore, The University of MelbourneWhen I was a child, I was intrigued by the Queensland box (Lophostemon confertus) growing in our backyard. I noticed its leaves hung vertical after lunch in summer, and were more or less horizontal by the next morning.
This an example of heliotropism, which literally means moving in relation to the sun. We can see it most clearly as spring arrives and various species burst into flower — you might even get the feeling that some flowers are watching you as they move.
Many of us probably first got to know of heliotropism at home, kindergarten or primary school by watching the enormous yellow and black flowering heads of aptly name sunflowers, which moved as they grew.
These flowers track the course of the sun spectacularly on warm and sunny, spring or summer days. Sometimes they move through an arc of almost 180⁰ from morning to evening.
So with the return of sunny days and flowers in full bloom this season, let’s look at why this phenomenon is so interesting.
The mechanics of tracking the sun
A number flowering species display heliotropism, including alpine buttercups, arctic poppies, alfalfa, soybean and many of the daisy-type species. So why do they do it?
Flowers are really in the advertising game and will do anything they can to attract a suitable pollinator, as effectively and as efficiently as they can. There are several possible reasons why tracking the sun might have evolved to achieve more successful pollination.
By tracking the sun, flowers absorb more solar radiation and so remain warmer. The warmer temperature suits or even rewards insect pollinators that are more active when they have a higher body temperature.
Optimum flower warmth may also boost pollen development and germination, leading to a higher fertilisation rate and more seeds.
So, the flowers are clearly moving. But how?
For many heliotropic flowering species, there’s a special layer of cells called the pulvinus just under the flower heads. These cells pump water across their cell membranes in a controlled way, so that cells can be fully pumped up like a balloon or become empty and flaccid. Changes in these cells allow the flower head to move.
When potassium from neighbouring plant cells is moved into the cells of the pulvinus, water follows and the cells inflate. When they move potassium out of the cells, they become flaccid.
These potassium pumps are involved in many other aspects of plant movement, too. This includes the opening and closing of stomata (tiny regulated leaf apertures), the rapid movement of mimosa leaves, or the closing of a fly trap.
But sunflowers dance differently
In 2016, scientists discovered that the pin-up example of heliotropism — the sunflower — had a different way of moving.
They found sunflower movement is due to significantly different growth rates on opposite sides of the flowering stem.
On the east-facing side, the cells grow and elongate quickly during the day, which slowly pushes the flower to face west as the daylight hours go by — following the sun. At night the west-side cells grow and elongate more rapidly, which pushes the flower back toward the east over night.
Everything is then set for the whole process to begin again at dawn next day, which is repeated daily until the flower stops growing and movement ceases.
While many people are aware of heliotropism in flowers, heliotropic movement of leaves is less commonly noticed or known. Plants with heliotropic flowers don’t necessarily have heliotropic leaves, and vice versa.
Heliotropism evolves in response to highly specific environmental conditions, and factors affecting flowers can be different from those impacting leaves.
For example, flowers are all about pollination and seed production. For leaves, it’s for maximising photosynthesis, avoiding over-heating on a hot day or even reducing water loss in harsh and arid conditions.
Some species, such as the Queensland box, arrange their leaves so they’re somewhat horizontal in the morning, capturing the full value of the available sunlight. But there are also instances where leaves align vertically to the sun in the middle of the day to minimise the risks of heat damage.
Plants are dynamic
It’s easy to think of plants as static organisms. But of course, they are forever changing, responding to their environments and growing. They are dynamic in their own way, and we tend to assume that when they do change, it will be at a very slow and steady pace.
Heliotropism shows us this is not necessarily the case. Plants changing daily can be a little unsettling in that we sense a change but may not be aware of what is causing our unease.
As for me, I still keep a watchful eye on those Queensland boxes!
In a UK study published today in Nature, scientists found Australia must keep 95% of coal in the ground if we have any hope of stopping the planet warming beyond the crucial limit of 1.5℃.
These findings echo the message of senior United Nations official Selwin Hart, who earlier this week urged Australia to end the use of coal by 2030. He warned if the world doesn’t boost climate action urgently, Australia can expect more frequent and severe climate disasters such as droughts, heatwaves, fires and floods.
Meanwhile, markets for coal seem to be sending the opposite message.
The price of Newcastle thermal coal recently reached a record high of US$180 per tonne due to rising electricity demand in India, China and other Asian countries. That seems to suggest whatever the consequences, Australia and the world are not going to give up on coal or other carbon-based fuels.
But it’s a mistake to place too much weight on fluctuations in coal markets. Earlier this year, the price was about US$50 per tonne and seemed likely to fall further. The current price tells us nothing about the choices we face in reducing emissions by 2030.
It’s entirely feasible for Australia to phase out thermal coal by 2030 — we just need political will.
World economies must decarbonise
The authors of the new modelling study in Nature examined the world’s reserves of oil, gas and coal, and determined how much would have to be left untouched for at least a 50% chance of limiting global warming to 1.5℃.
Overall, it found nearly 60% of the world’s oil and fossil methane gas, and 90% of coal must remain unextracted by 2050. But the estimate for exporters like Australia is even higher.
This means production in most regions must peak now, or in the next decade, and that stronger policies are needed to restrict production and reduce demand.
The study reinforces how urgent it is to decarbonise economies. As Selwin Hart, the Special Advisor to the UN Secretary-General on Climate Action, noted in his speech to the Crawford Leadership Forum:
Decarbonisation of the global economy is quickly gathering pace. And there are huge opportunities to create more jobs, better health, and a stronger and fairer economy for those countries and companies that move first and fastest.
Is an end to coal feasible?
But would it really be possible for Australia to phase out coal by 2030, as Hart insists?
To consider this, it’s important to first distinguish between thermal coal and metallurgical coal. Thermal coal is used to generate electricity, while metallurgical coal is used in steelmaking.
Blast furnaces using metallurgical coal will ultimately be replaced by alternative technologies, such as using “green” hydrogen produced using clean electricity.
That process has begun, but it will take a long time, and can’t start until electricity generation is decarbonised. So, it makes sense to focus on phasing out thermal coal first.
But if decarbonisation of the global economy requires a rapid end to the use of thermal coal, why has its price suddenly surged?
A number of factors determine the thermal coal market, and fluctuations don’t tell us much about what the coal market will look like in 2030.
The recent increase in prices was caused by a combination of the rapid recovery from the pandemic recession, rising gas prices, weather-related disruptions to coal supply from Indonesia, and drought in China. It’s worth noting that despite high prices, the volume of seaborne thermal coal has actually declined.
Ending thermal coal in Australia would be easy
Given a modest amount of political will, or just the end of obstructionism from the federal government, Australia could easily replace coal-fired electricity generation with a combination of solar and wind, backed by storage.
Most of Australia’s coal-fired power plants were commissioned in the 20th century with obsolete sub-critical technology, and would be approaching the end of their operational lives even in the absence of climate change concerns.
Bringing those dates forward to 2030 or earlier could be almost costless. We could easily double our current rate of installation of utility-scale solar and wind generation, if the federal government got out of the way and let the states tackle the job.
Only five coal plants have been commissioned this century. The Bluewater plant in Western Australia has already been written off as worthless because of competition from solar and wind power.
The remaining four, all in Queensland, have a total capacity of less than 3 gigawatts. Allowing for the fact solar photovoltaic (PV) only operates in daylight hours, this is about the same as one million 10-kilowatt rooftop solar installations (about average for new installations). Queensland already has more than 750,000 solar rooftops, and capacity for another million.
More notably, the cost of decarbonising electricity supply is a fraction of the amount we have collectively spent to respond to the problem of the COVID-19 pandemic. Not only is COVID a smaller threat in the long run than climate change but a comprehensive response to pandemics requires us to stabilise the climate and stop the destruction of natural environments.
In a report I prepared for the Australia Institute last year, I found Australia could successfully transition the workforce with a mixture of measures including early retirement, retraining, and investments in renewable energy targeted at coal-dependent regions.
The cost of this would be around A$50 million a year, over ten years. That’s less than the estimated cost of a week of COVID lockdown in Sydney.
But would this condemn developing countries to energy poverty?
The reality is it makes economic and environmental sense for all countries to shift away from coal.
The central government in China has committed to reach net zero carbon emissions by 2060. But many provincial governments still see investment in coal plants and other polluting industries as an engine of growth, not to mention a lucrative source of kickbacks and donations.
The picture in India is similarly complex. Coal remains the main source of electricity, but most electricity generation businesses have abandoned new investments in coal-fired power and many have stopped bidding for access to domestic coal supplies.
We can’t do much to influence energy policy in China and India. But a commitment to reduce and ultimately eliminate exports of thermal coal would not, as some have suggested, condemn these and other developing countries to poverty.
Rather, it would strengthen the hand of advocates of clean energy against the established interest groups that defend coal.