Skeptics claim that greenhouse gas levels fluctuate naturally - and while this is true, it does not tell the whole story.
By studying gases trapped in ancient ice, scientists have determined that CO2 levels fluctuated between 180 ppm during ice ages and 280 ppm in warmer periods. As of January 2017, levels are currently at 406 ppm. This may not seem like a significant amount but consider that only 100 ppm separates an ice age from a warm period, and those shifts occur over thousands of years. We have increased global CO2 levels by nearly 50% - 120 ppm - in 300 years, with a lot of that occurring in the last 70. Moreover, some greenhouse gases like chlorofluorocarbons (CFCs) are entirely manmade and were not present in the atmosphere before we created them.
And that concludes this week’s Science Fact Friday.
Wind energy has the problem that the turbine blades cause a stroboscope effect when the sun is behind them, plus they're huge and "ugly" (and there are other problems, as they need a particular type of terrain that may have to be cleared). Traditional water energy has the issue of huge dams that aren't exactly friendly to the environment downstream (and drown everything where the dam lake is). There are alternatives here, too, though I'm not sure how much research is done.
Geothermal energy has its own issues (earthquakes, for instance), not just availability, but Iceland is way ahead there for obvious reasons.
Many of those are excuses if you ask me (sure, it all costs money, there's technical and environmentl issues still to be overcome, but come on), but that's part of what keeps the use of renewable energies from spreading faster. Then of course there's the lobby of fossil energies. They got money governments want to keep.
ETA: Man-made global warming sucks.
And now some conspiracy theorists might say that aliens caused the global warming to eventually get a big amount of human soup.
I always love your fact Fridays haha