Scores of Labour MPs have urged the prospective prime minister Andy Burnham to rule out the “tin-eared” and “deluded” development of the Rosebank oilfield in the North Sea, which new research indicates would produce as much carbon dioxide as the UK does in 10 months.
Estimates seen by the Guardian show that Rosebank, which mainly contains oil, would produce about 250m tonnes of CO2 over its lifetime. That is the equivalent of about 70% of the UK’s annual emissions.
Marine scientists have expressed concerns following a 60 per cent drop in migrating whales seen off South West WA’s coastline compared to previous years.
Sharks are front of mind for many Sydneysiders and coastal New South Wales residents. In January, a teenager died amid a spate of attacks in and around Sydney. This month, a woman was bitten by a large great white while swimming close to shore and between the flags at Coogee Beach.
The NSW government has ruled out culling great whites, a protected species, but is considering a bull shark cull. This week, it announced $A34 million in new funding to expand its shark-spotting drone program, as part of a larger shark safety program. It will mean daily drone surveillance of around 70 beaches, including every Sydney beach and one for each coastal council.
While spotter drones are a genuine advance in shark detection, they’re not foolproof. After flying spotter drones over Sydney beaches for a season, this article’s lead author found shark detection didn’t mean protection.
Before drones, authorities relied on infrequent spotter flights over popular beaches. As a result, few sharks were sighted.
Drones have made it much easier to watch the ocean from above for extended periods. As a result, spotting a shark is now more likely. But more sightings doesn’t necessarily mean there are more sharks.
As authorities roll out their expanded drone program, we can expect to see a surge in shark sightings and more beaches closed as a precaution.
Detection doesn’t mean protection
Researchers have used drone footage to map shark movements and assess the risk to help pilots decide when to evacuate beaches. This showed the risk was low. At three Queensland beaches, only 4% of sightings over four years were bull sharks and no white or tiger sharks were seen at all. Drones mostly spotted small whaler sharks.
To date, there’s no published peer-reviewed research showing drone surveillance reduces shark bites. This isn’t an oversight. Shark bites get a lot of media attention, which makes them seem common. In reality, they are extremely rare.
Millions of Australians swim in the ocean every year. Last year, there were 23 bites across all Australian waters.
Their rarity means no research could realistically gather enough data to prove drone spotting led to a fall in bites, given many other possible explanations and factors.
Drone spotting is not flawless. Even in good conditions, drone pilots only detect around 40% of sharks swimming under the surface in real time. The figure rises to about 50% after careful post-flight review.
Detection is even more challenging when water isn’t clear. Murky water is common after periods of rain.
Drowning is a much bigger risk than sharks
Shark bites make headlines and capture public attention. This gives many of us a skewed view of what the real risks are of swimming in oceans and estuaries.
Deaths due to shark bites in Australia averaged about 3 per year over the last decade.
But in just the last year, 154 people drowned along the Australian coast. This included 30 deaths due to the single biggest beach hazard – offshore flowing rip currents.
In an average year, rip currents cause more deaths than bushfires, floods, cyclones and sharks combined. Each death causes significant trauma for loved ones and the community.
It’s worth asking why a spate of shark bites led to major public investment while deaths from rip currents do not tend to attract the same spending.
If the goal of the NSW government was to save the most lives at the beach, it might have made sense to first tackle drownings due to rip currents. Local governments could be funded to extend and expand their beach lifeguard services.
Evaluation before expansion
Drones may well prove useful tools to boost beach safety. The scale and cost of the NSW drone spotting program makes it a world-first.
But it’s an open question whether rapid expansion of drone spotting will boost the safety of beachgoers, given shark bites are the rarest hazard. The NSW government announced the investment without an evaluation of evidence for spotting program effectiveness.
It may not be possible to prove drones reduce bites, but we could still evaluate what they demonstrably do: shark detection and species identification, response times, and how often drones assist with other rescues.
We should expect the drone spotting program to lead to more frequent and more extended beach closures. That could have unintended consequences, such as a fall in beach visitors and a drop in revenue for coastal economies.
If closures get more frequent and become the new norm, people may seek out unpatrolled beaches with no flags, lifeguards or drones. That would be a dangerous outcome, as almost every coastal drowning occurs on unpatrolled beaches or outside lifeguard patrol hours and times.
Until we have evidence to say drone spotting will help, we should be honest about what this program will do.
Their clearest life-saving value may be elsewhere: in Queensland’s trial, drones were also used to spot swimmers caught in rip currents and locate missing persons.
Spotting for sharks alone looks to be about reassurance – not true protection.
Samuel Cornell previously worked in a casual capacity as a drone pilot for the Australian UAV Service and received funding from Surf Life Saving Australia during his PhD via the Beach Safety Research Group.
Rob Brander receives research funding from Surf Life Saving Australia through philanthropic donations made to the UNSW Beach Safety Research Group.
Sydney is no stranger to extreme heat. In January 2020, Penrith in Western Sydney reached 48.9°C, the highest temperature ever recorded in Greater Sydney.
Now imagine Penrith in 2050: the heat lasts longer, extreme heat events happen more often, and power goes out on the hottest days because the grid can’t cope.
Our recent research, published in the journal Energy and Buildings, shows Sydney apartments built to current building codes may become very uncomfortable by 2050 far more often. In fact, we found that inside an apartment built to today’s standards, temperatures would stay above 30°C for several days in a row.
Sydney is rapidly rezoning, leads the nation in apartment living, and is still racing to build more homes. Many of the developments approved today will still be standing in 2050.
But while we are building for the future, we are designing for the past.
Building for yesterday’s climate
Our study used the latest climate projections for Sydney to test apartments built to today’s standards in inner-city Redfern and Western Sydney’s Penrith.
By the 2050s, owing to climate change, Sydney’s median outdoor temperatures could be up to 5°C higher than today in its hotter inland areas under the highest-warming regional projection (a high greenhouse gas emissions scenario known to researchers and policymakers as SSP3–7.0), with hot days becoming longer and more frequent.
We found apartments built to today’s standards could be too hot for comfort for the equivalent of about four weeks a year in Redfern and more than seven weeks in Penrith.
The level of indoor overheating could pose a serious heat stress risk to residents.
Design matters. West-facing homes receive intense afternoon sun, while top-floor apartments absorb heat radiating through the roof. Opening a window offers relief when air outside is cooler. But many apartments lack cross-ventilation, and others have windows too small to remove the heat that builds up indoors.
A threat faced unequally
Older people, poorer communities, and people with chronic illnesses face the greatest risks.
Our projections show people living in Penrith could face almost twice as much overheating inside their homes as people in Redfern.
Air conditioning (AC) isn’t always an option. This is especially true for renters, elderly residents, and low-income households who make up much of western Sydney’s growing apartment population.
Some renters may not be allowed to install AC. And even where it’s already installed (it is not mandatory in new builds), not everyone can afford to run it.
One national longitudinal study estimated about one in 14 Australian households (around 7% of households) already spends more than 10% of their income on energy bills.
A survey of more than 1,000 Australian found 49.7% of households resist using their AC units on hot days to save on summer electricity bills.
Running air conditioners during extreme heat also puts enormous strain on the electricity grid. On hot summer days, NSW peak electricity demand can surge above 13,000 megawatts, well above the state’s average operational demand of around 7,700 megawatts, straining the grid and increasing the risk of blackouts.
During a blackout, even homes with AC may lose cooling when they need it the most. Air conditioners also release heat outdoors, making already hot neighbourhoods even hotter.
To sum up: many people cannot rely on AC and may not be able to easily relocate during a heatwave.
Homes should be able to keep people safe even when AC is not available.
Two changes could make a major difference
The solution starts with building standards. Australia’s current construction code focuses on predicted energy use for heating and cooling based on historical weather data, not the warmer climate those buildings will face. They should also test how long a home can stay at safe temperatures in a warmer future, especially during heatwaves, without relying on AC. This is known as a building’s “passive survivability”.
To make homes safer, we need two changes to building standards.
First, new apartments should be tested against a range of future climates, including longer and more intense periods of heat.
Second, standards should set a minimum time that a home must stay safe without air conditioning and provide practical guidance on how to achieve this.
Better design can cut the risk
Adding more insulation on its own doesn’t go far enough to protect apartments from future heat. But our study found several design changes that can make a real difference:
External window shades block sunlight before it heats the apartment. We found they reduced the time apartments were too warm by up to 32%
Safe night-time ventilation – meaning windows you can leave open overnight – lets trapped heat escape after sunset. We found it reduced overly warm hours by up to 34%, especially in Penrith
Lighter roof colours also helped protect top-floor apartments.
The best results came from combining these measures with double glazed windows and insulation. Together, they cut the risk of Sydney apartments becoming too hot in the 2050s by up to 94%.
Australia needs more apartments. But homes approved today must still protect people decades from now.
Building codes need to change so the country’s growing apartment stock stays safe, liveable and resilient in a hotter future.
Our study focused on Sydney, but it is likely these findings are applicable across many other parts of Australia, and the region.
More broadly, planning for new developments should also combine urban-scale heat mitigation measures (such as urban greening, light-coloured or reflective materials for roofs, roads and pavements, providing shade for built surfaces, and designing with water) with building adaptation to offset the impacts of climate change.
Shamila Haddad has been supported by Sydney Horizon Fellowship.
Arianna Brambilla, Jingjing Liu, and Mat Santamouris do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.
