How does Climate change cause Rise in UV Radiation?
UV radiation is greatest in summer as the sun is high in the sky and its rays pass through less atmosphere before reaching the earth's surface. In winter, the sun is lower in the sky and its rays have a longer trek. In recent decades UV radiation has generally been affected by changes in the stratospheric ozone and by global climate change. The decrease in stratospheric ozone has allowed more UVB (the higher-frequency, more harmful type of UV) to reach the Earth's surface.
This is also connected to global warming and extreme weather events. The atmosphere acts like the glass in a greenhouse, allowing short-wave UV radiation to travel through relatively unimpeded, but trapping some of the long-wave IR radiation which is trying to escape. This process makes the temperature rise in the atmosphere just as it does in the greenhouse. To exacerbate the problem more fossil fuels for the past 50 plus years have Increased concentrations of greenhouse gases, such as CO2, reducing the amount of outgoing longwave radiation (OLR) to space; thus, energy accumulates in the climate system, and the planet warms. This causes many to wonder, “is the sun getting stronger?” It's a question many have wanted to VERIFY. According to Scripps Atmospheric Scientist Ray Weiss the answer is no, even though it feels that way. He says it's not that the sun is stronger, but rather the ozone layer is thinner meaning more UV rays are coming through.
the negative effects of extreme solar UV radiation on humans, terrestrial and aquatic ecosystems, materials, and air quality have just begun. Following the decline in total ozone between the 1960s and 1990s, the levels of total ozone outside the polar regions have stopped decreasing since the late 1990s, consistent with the slow decline of ODSs over the same period. Several datasets indicate that total ozone has increased by 1% since 2000 in the latitude band 60° S–60° N in response to stratospheric ozone recovery. However, there is disagreement about the magnitude and statistical significance of this increase. Presumably any increase in ozone would have resulted in a corresponding decrease in the surface UV-B radiation at the Earth's surface, this did not occur instead we have seen a global increase of UV and extreme weather events from drought to tornadoes, hurricanes winter storms, animal migrations, permafrost loss and floods!
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 and infertility...Unless a male has eumelanin brown or black skin UV-A induced disruption of chromatin structure renders the DNA vulnerable to damage, with resultant DNA fragmentation. Thus, UV-A affects the sperm quality, which in turn can lead to infertility. UV Radiation may also destroy sperm cells and the stem cells that make sperm. Fertility rates have fallen worldwide over the last 50 years especially in European countries and chemicals found in everyday products are thought to be playing a role –especially those in your sunscreen.
Researchers at the University of Copenhagen found that filters commonly used in sunscreens to absorb ultraviolet light have an affect on male fertility by stopping sperm from functioning properly. The issue attracted media attention after a 2017 meta-analysis found that sperm counts had declined by 52.4 percent between 1973 and 2011. The decline is particularly prevalent in Western countries with white majorities such as New Zealand and Australia, Europe and North America. Obesity, a lack of physical activity and diets high in ultra processed food are all culprits, “The same factors that harm health in general usually are also harmful to semen quality,”