Australia – where the Sun hits the hardest

Today, I’d like to talk about solar radiation and its consequences in Australia (it is, after all, linked to astronomy and heliophysics).

Last week, a friend sent me this incredible map.


A map of the global irradiance (power of solar radiation) on Earth for the period 1990-2004

Look at the bright red spots in the Pacific, mid-Atlantic and Australia where irradiance (the power of solar radiation) is highest.

Australia receives much more solar radiation than California or even the Mediterranean famed for its sunny summers and beautiful beaches. And while it does not necessarily mean blue skies and sunny days (solar radiation can be pretty high on a cloudy day), there is a correlation between strong solar radiation, heat, the climate, and health. Solar radiation includes visible light, but also infrared radiation responsible for the “heat” sensation you feel and ultraviolet radiation responsible for sunburns. 

So, what is irradiance? Irradiance is the power of electromagnetic radiation on a unit of area, and is measured in watts par square metre (W/m2). In Australia, it reaches the scale’s 2nd maximum of 270-280 W/m2 on a large portion of the country. The sunlight that hits Australia is really strong, and there’s lots of it.

In fact, the map shows there are only three important continental areas to reach such highs: Australia, eastern China (Tibet) and central Africa at the intersection of Sudan, Chad, southern Libya and southern Egypt. Australia is the largest, making it, some claim, the world’s sunniest country.

What does this mean? Simply, that Australia is scorched by the Sun. So much irradiance means various things:

  1. It’s a great holiday destination
  2. It’s a very good place to produce solar energy
  3. But, it’s also really bad for your health
  4.  and it means extreme weather

Today I won’t elaborate on 1. because we all already know that 😉 (and if you don’t, come visit! You’ll love it). Rather I’ll focus on the science and impacts.

Solar Farm in the USA credit: U.S. Air Force/ Nadine Y. Barclay

Solar Farm in the USA credit: U.S. Air Force/ Nadine Y. Barclay

2. So much irradiance tells me Australia is a great if not the best place on Earth to produce solar energy. The map also made me realise Australia is probably the safest, most politically stable and most accessible place on Earth among the areas where solar radiation is highest. The sun is shining strong throughout the year, and we have large flat uninhabited areas ready to host giant solar farms. And yet, the largest solar farms are located in California, Spain, and…Germany!

In August, The country’s top expert body on climate change, the ex- government-funded Climate Commission (scrapped by the new government and now reborn as the crowd-funded Climate Council) recognised this, writing:

Germany receives less sunlight than Victoria but has more installed capacity than any other country (…)

Australia is the world’s sunniest continent with enormous, but largely underutilised, potential for solar power generation.

In fact, Australia doesn’t even make it into the long list of the largest photovoltaic plants in the world. You have to wonder about that…I know it’s not that simple, because Australia is largely uninhabited, making it very hard and very costly to build such stations in the middle of nowhere and connect them to the grid. Still, you’d think the investment would be worth it. 

To be used without moderation!

To be used without moderation!

3. Such strong solar radiation also means high ultraviolet radiation (UV is part of the electromagnetic spectrum, like visible light and infrared), which is really bad for your health. In fact, Australia has the highest level of skin cancer in the world. Some 2 out of 3 Australians will be diagnosed with skin cancer before the age of 70, and Australians are 4 times more likely to develop skin cancer than any other form of cancer. So, if you’re coming from abroad, cover up, wear sunglasses and hats and leave your 15+ sunscreen at home, as the minimum recommended here is 30+.

4. Finally, the main point I’d like to raise is strong solar radiation also means extreme weather, and it’s getting worse (Read this page to better understand the complex links between solar radiation and greenhouse effect). Australia had a record drought for the better part of the last decade and regularly experiences terrible bushfires. A couple of years ago, Australia also experienced its worst summer. It was so bad that it became known as the Angry Summer. The Climate Council, at the time, produced this scary map summarising it:


In 90 days, 123 records were broken throughout Australia, with 7 days in a row above 39°C for Australia as a whole, the hottest january on record and the hottest summer on record.

Heat records were broken all over the country. The hottest day, hottest month, and hottest summer ever were recorded that year. The heat was so bad that in many areas the only thing you could do was stay inside all day with the air conditioning on.

This was two years ago. Just a fews days ago, this map was also released, showing Australia experienced its hottest September month ever.

The image shows the maximum temperature deciles across Australia for September 2013, showing which areas are the highest on record. Credit: Australian Bureau of Meteorology

The image shows the maximum temperature deciles across Australia for September 2013, showing which areas are the highest on record. Credit: Australian Bureau of Meteorology

The story was picked up around the globe by science sites and IFLS on Facebook, whom I’ll just quote because their post is spot on:

Australians have just experienced the warmest September since records began, with temperatures almost 3 degrees Celsius above the long-term average. The latest record also makes the past 12 months the warmest documented and 2013 will likely be the hottest calendar year in Australia, surpassing 2005. Climate change is increasing the risk of more frequent and longer heatwaves and more extreme hot days, as well as exacerbating bushfire conditions in Australia.

To nail the point about climate change, I urge you to read the Climate Council’s summary of the latest IPCC report on Climate Change, well presented in layman’s terms here. You can also read this article about the increasing acidification of our oceans caused by their absorption of massive amounts of CO2 (emitted by guess who), at levels not seen in 300 million years.

To conclude, it feels to me Australia experiences what might be the world’s strongest solar radiation (and worsening), and it’s a terrible challenge for the country, putting it with other places, particularly in the Pacific and arctic regions, on the frontline of climate change. It has terrible consequences for our environment, for our health and so for our economy.

But it could also be a blessing. Australia could seize this opportunity and invest in a green revolution to harness the Sun’s power in our country, which would in the long term ensure energy independence, sustainability and cheap, permanent energy for the entire country. Surely that is worth thinking about. And like this document will show – published by the Climate Commission in August just before being axed -, there is hope.

4 thoughts on “Australia – where the Sun hits the hardest

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