Keith,
Just using your own numbers here:
So, CO2 has increased from 300 parts per MILLION to 400 Parts per MILLION. Lets take this in context. Now, my meter at home rarely shows greater than 50ppm naturally, and when I say that is rare, I mean really rare. There are however some days where CO2 can be found in the air around us. Open the windows, and there's no change. Now if you live in a city, well, your numbers are probably going to be higher than mine living in the middle of nowhere.
A 33% increase in something which NOW represents .04% of the atmosphere, seems a bit unlikely to be causing a temperature change due to its insulating value. Since the vast majority of our heat comes and goes as light (at some spectrum), it seems unlikely that this is a cause. But, who knows. I'd rather believe that there has been weather for the past x billion years, and there will be weather for the next x billion years. These people who predict the weather can't predict correctly for the weather we experience Currently, in real time! How the hell can they predict much more than that.
They're ok at seeing conditions 1000 miles away and saying these may or may not hit us later. As long as it's a gigantic storm. Well, I can pick up the phone and call friends and family in Indiana and get tomorrows PA weather a lot closer than anyone on TV predicts.
Funny enough, I've been around farming my entire life (not that I enjoyed very much). I live on a farm now. Now, I've not made weather a lifetime study, but I have fairly decent recollection and it 'has' been a thing that affected me daily since childhood. In my lifetime, I have NEVER heard that the weather in Pennsylvania was "Normal". EVERY single year of my life, there have been some "abnormal weather conditions". Rainy times, dry times, stormy times, floods, droughts, blizzards, ice storms and hail, hurricanes, tornadoes, you name it, we've had it. I remember 'The Hole in the Ozone". I also remember when it was made illegal to sell gizmos that create Ozone cause evidently the hole in the ozone was total BS. I think the whole global warming thing follows the ozone thing.
I was reading an article yesterday about the conditions in Texas. This writer says that there has been 6" of rain in TX this year. Normal rainfall is 12" annually. Then he says it would take 22" of rain in one month to get back to "Normal". Wtf is normal and where did they come up with that math? Almost 2 years worth of rain in a month to get back to normal alright. And people sit and read this crap and just eat it up.
Btw, our "drought" in PA ended. We must be back to abnormally wet now cause it'd be a real shame if we had 'normal weather" for a while. I'm almost afraid to find out what normal is. But, I really think abnormal, is normal.