Has UV Solar Radiation Increased by 1,000% In A Couple Of Decades?
UV radiation reaching the surface of the Earth varies significantly from place to place and even from hour to hour. Although there have been various sporadic UV measurements conducted throughout the latter half of the 20th century, satellite UV measurements have only been conducted since 1978, thus there simply is no reliable long term UV data available prior to that date. Thus, anyone claiming that the amount of UV reaching the surface of the planet prior to 1978 is such and such, is simply lying. Regardless, there are various sources which claim that UV radiation was fairly muted from approximately 1960 to 1980, when it then began to increase.
The amount of increase of UV-A and UV-B radiation around the world has been claimed to total approximately 7% since 1980, and there is sufficient hard data to back up this claim, so let's accept it.
The effects of UV-A and UV-B on human skin are not necessarily linear. 7% more radiation will not automatically lead to 7% greater impact on the dermal layer. However, it still has to have some level of correlation and it's quite unlikely that a 7% increase would double the deleterious radiation effects on the skin. So let's be more than generous and allow that a 7% increase in UV radiation will cause 20% more damage, or about three times to the ratio of the radiation increase itself.
Therefore, if you exposed skin to the typical UV-A and UV-B at the same latitude on the same day in 1980 and then today, you'd expect that there would be 20% more skin damage in the form of sunburn, etc.
That figure does seem to jibe to some degree with the increase in skin cancers. In the last seven years, skin cancer rates are up 46% in Britain, 42% in Australia, and as much as 50% in young Caucasian women in the United States.
OK, then, let's take it one step further. Let's assume that 7% more radiation causes 50% more damage. It's a bit of a difficult statistic to swallow, but let's continue to be generous with our suspension of disbelief.
Now let's take the example of a human guinea pig to run a sunlight exposure experiment. Let's see... who shall we use... ok... how about Hal?
You see, Hal spent every single sunny daylight hour every single summer in the swimming pool of his house when he was growing up. In those days, people rode dinosaurs to work and cooked brontosaurus burgers on the BBQ, so it's not like we had even heard of sunscreen or the need for it. When it was sunny, we'd go outside. I never remember wearing a "wide brimmed hat" or any of the other accutrements which seem to be de rigeur these days when venturing outdoors. I wore a speedo and a smile. That was it.
Therefore, starting around the end of May and all the way up to the beginning of September, if it was sunny outdoors, I would be out there. In the pool, out of the pool, but never in the shade for more than a minute or so.
Let's do some calculations:
The period of time in question is 15 weeks, or 105 days.
About 15 days were washouts, leaving 90 days.
The location was southern Ontario, around 43 degrees of latitude, so the average duration of the daylight hours in the summer season is 12.
Therefore, we have 1,080 hours of sun exposure per year. Let's allow for a few pee breaks and cut it down to 1,000 hours.
I lived in that house with that pool for 12 years.
Total: 12,000 hours of sun exposure on my skin.
During those 12,000 hours I got about half a dozen sunburns that led to some minor peeling total. Nothing else.
Therefore, we can estimate that approximately 2,000 hours of sun exposure would result in one fairly minor sunburn on my skin at that time.
That was long ago, but the last time I checked, I still had the same skin I have now. Susceptibility to sunburn does not necessarily change to any noticeable degree from youth onwards, so we should expect that I should still be getting sunburned at about the same rate I was then.
Well... not exactly.
Earlier this week I decided to go sit in the pool where I live now for a bit. I was waiting for a call, so I checked my cell phone as I put it down. It was 2:05 pm. I put on my trunks, jumped in, splashed around for a bit, then got out and dried off enough to pick up my cell phone and check the time again: 2:32 pm. I was outside for another couple of minutes to dry off and then went indoors for the rest of the day. Therefore, we can confidently assume that I had been exposed to sunlight for 30 minutes.
And note, that this sunlight is 7 degrees of latitude further north than the southern Ontario pool of my youth, so the incident rays of the sun are more oblique, thus less powerful.
This was the single worst sunburn of my entire life, and when you consider that I have lived in the deserts of California and Nevada, plus a few more years in the tropical sun of Florida, the Caribbean, Australia, and Africa, that's really saying something!
I suffered not only sunburn on the skin causing dermal damage and peeling, but a borderline sunstroke which kept me up all night with severe pain in my joints and massive dehydration. I must have quaffed at least six litres of ice water overnight while I couldn't sleep.
Ok... what's the deal here?
There is no way possible that a 7% increase in the UV-A and UV-B radiation could create an effect like that on my skin. Either I was impervious to sunlight when I was younger (next to biologically impossible) or there is a whole whack more than 7% more sunlight radiation hitting the surface of the Earth now than there was before!
I can't see anything less than a 1,000%, or ten fold, increase in UV-A and UV-B causing this kind of damage so fast. Maybe considerably more than 1,000%!
This is a situation which requires immediate and comprehensive research, likely more than any other environmental climate change issue on the planet today. If the amount of UV radiation which is penetrating the atmosphere is sufficient to cause that much damage to someone who would only get lightly toasted earlier in his life, we have an extremely critical problem which dwarfs just about anything else that humanity is currently confronting!
What are the long term effects of this level of UV radiation on the flora and fauna of the planet? What kind of impact does this have on the ecological cycles which regulate all life?
It may just be high time that we as a species drop our media-soaked distraction and demand that the issue of increased solar radiation on the surface of our only planet be examined to a much greater degree than it is now. Something drastic is happening outside our windows, and if it is anywhere near as critical as my example leads one to believe, our entire ecosystem and the very future of our civilization is at stake.