[tuzo29]

Just a follow up as I have continued to investigate this topic this week. Looking at the thread from a few years ago there were several posts about research by some Danish scientists on how cosmic rays may lead to more clouds. I believe this is a possible cause for global temperature change, although it's far from a strong theory yet. When our solar system is in one part of the galaxy that has more cosmic rays, then we are going to have more clouds and colder weather. When the sun goes through its 11-year cycle of solar flares and that affects the cosmic rays that reach Earth, we get more or less cloud cover. OK, plausible theory. Have we seen a secular trend in cosmic rays in recent decades to explain the warming of our planet? According to NOAA data, we have not (https://www.ngdc.noaa.gov/stp/solar/cosmicrays.html). If not, then there must be something else going on. Sure, cosmic rays can change our global temperature over millions (or billions) of years, but over 5 decades? In the past 50 years we haven't moved to another part of the galaxy. Also, there's been no measurably significant change in the solar activity to point to either (other than the 11-year cyclical changes as shown in the NOAA data that don't trend like global temperatures have over the last century). There are lots of things in the universe that can impact global temperature, but we are looking for something that can explain the warming over 100 years or less. Cosmic rays doesn't fit for that.