Not only is Earth suddenly spinning faster, but our Sun is getting more active than NASA predicted. The Sun appears to have a cycle of about 11 years during which it waxes and wanes. Its activity is measured by the number of sunspots on its surface, which have been counted each day since 1755.
"We do still see an increase in UV on a 30-year timescale, but it's moderate, it could have been worse, and it appears to have leveled off." In the tropics, the increase has been minimal, but in the mid-latitudes it has been more obvious.
Australia has some of the highest levels of UV radiation in the world – in fact, UV radiation is strong enough to cause sunburn in as little as 11 minutes on a fine summer day. UV radiation from the sun is also one of the best natural sources for vitamin D so a balance is important.
The depletion of the ozone layer leads, on the average, to an increase in ground-level ultraviolet radiation, because ozone is an effective absorber of ultraviolet radiation. The Sun emits radiation over a wide range of energies, with about 2% in the form of high-energy, ultraviolet (UV) radiation.
During summer, the Earth's orbit brings Australia closer to the sun (as compared to Europe during its summer), resulting in an additional 7% solar UV intensity. Coupled with our clearer atmospheric conditions, this means that Australians are exposed to up to 15% more UV than Europeans.
UV problem of another kind
"Tasmania is unique with the fact that in summer it gets to extreme level, and in winter it doesn't even get to moderate," Mr Carr said.
More about ozone layer depletion
This includes a five to nine per cent depletion over Australia since the 1960s, which has increased the risk that Australians already face from over-exposure to UV radiation resulting from our outdoor lifestyle.
UV radiation is generally affected by changes in the stratospheric ozone and global climate change. Decreased stratospheric ozone allows more UVB (the higher-frequency, more harmful type of UV) to reach the Earth's surface.
The absolute peak of the sun's intensity occurs in June, which is when the summer solstice happens. That's why sunburn happens more often during the late spring and early summer than any other time of year: the sun angle is significantly higher.
Dr Ahmad Hasanien, a skin cancer expert explained that 'During summer, the Earth's orbit brings Australia closer to the sun, resulting in an additional 7% solar UV intensity. Coupled with our clearer atmospheric conditions, this means that Australians are exposed to up to 15% more UV than Europeans'.
The stratospheric ozone layer absorbs the biologically damaging wavelengths of ultraviolet (UV) rays but in the 1970s, Australia's ozone layer was severely thinned as a consequence of heavy use of ozone-depleting, substances such as chloroflurocarbons (CFCs) and hydro-chloroflurocarbons (HCFCs).
New Zealand's rather cool and temperate temperatures can easily hide the harmful effects of the sun. Yet in any season and any weather, the New Zealand sun can burn. Many people say they get more sunburned in New Zealand than anywhere else in the world, even Australia!
Because the Sun continues to 'burn' hydrogen into helium in its core, the core slowly collapses and heats up, causing the outer layers of the Sun to grow larger. This has been going on since soon after the Sun was formed 4.5 billion years ago.
The Sun is becoming increasingly hotter (or more luminous) with time. However, the rate of change is so slight we won't notice anything even over many millennia, let alone a single human lifetime.
Our sun is getting brighter. If you could travel back in time to the dawn of the solar system 4.5 billion years ago, you'd find a star that was about 30% dimmer than it is now.
At mid-latitudes, such as New Zealand, it is thickest during spring and thinnest during autumn. This means the ozone layer over New Zealand thins during summer, providing less protection from UV sunlight when we are closest to the sun and the sun is highest in the sky.
On Dec. 29, 2003, a world-record UV index of 43.3 was detected at Bolivia's Licancabur volcano. The UV index is used to forecast the strength of the sun's ultraviolet rays.
Winter Sunlight
UVB rays, the main cause of sunburn, are the strongest in the summer. However, UVB rays can burn and damage your skin year-round, especially at high altitudes and on reflective surfaces such as snow or ice.
Risks. Sunburn is a sign of short-term overexposure, while premature aging and skin cancer are side effects of prolonged UV exposure. UV exposure increases the risk of potentially blinding eye diseases, if eye protection is not used. Overexposure to UV radiation can lead to serious health issues, including cancer.
The higher the UV Index score, the greater the amount of potential skin and eye damaging radiation. At high UV Index levels (6 or greater), significant damage can occur in just a few minutes. Sunburn is the result of overexposure to UV rays from the sun.
The earth's ozone layer is on track to repair itself in four decades. Researchers have even found a significant thickening of the ozone layer compared to 2018 levels, according to a report released yesterday (Jan. 9) by the United Nations Environment Program (UNEP) and the World Meteorological Organization (WMO).
The ozone layer protects life on Earth from the sun's most harmful rays. The discovery of the ozone layer hole in the 1980s promoted successful international cooperation to phase out the use of harmful chlorofluorocarbons (CFCs). Scientists say the ozone hole is continuing to shrink and could fully repair by 2050.
In this NASA false-color image, the blue and purple shows the hole in Earth's protective ozone layer over Antarctica on Oct. 5, 2022. Earth's protective ozone layer is slowly but noticeably healing at a pace that would fully mend the hole over Antarctica in about 43 years, a new United Nations report says.