With absolute certainty, the planet has warmed up over the last 150 years.
Most likely, it's been a bit over 1 deg. C over that time(around +1.6 Deg. F) and I can guess that humans have been responsible for around half of that warming.
Scientists that state with certainty that it's all been from humans can't know this. It's possible that most of it has been from humans............but since it was this warm or warmer 1,000 years ago, just over 2,000 years ago and 3,500 years ago and we don't know why the planet warmed up then, we can't know this warming was not part of that same cycle(happens around every 1,000 years).
Why do I think around half from humans? Because that's what the physics of CO2 as a greenhouse gas in the atmophere supports.
We covered the temperatures and studies already. https://www.marketforum.com/forum/topic/5853/
Now, let's find out what the warming is actually doing to our weather/climate and life on this planet............starting with tornadoes. Information that I show here will be mostly data/observations and based on scientifically backed laws that I can clearly state or prove, not opinions or related to politics.
Tornadoes and global warming will be our next discussion. I'm taking guesses on the effects and comments, especially funny ones if they come to mind.
Please disagree with me and ask questions.
Much of the world assumes alot about climate change but what they know is almost entirely based on trusting their sources..........what they have been told, read or heard. I will also get to the bad stuff as there are 2 sides.
Based on data, there appears to be no correlation.
I have seen data here which proves hurricane activity is down so I assume tornados are down as well. This should make the warmers happy but they some how use films of big tornados and hurricanes to try to scare people anyway. Wow pretty much how the same crowd tries to scare people with fake news and trump
Tim and mcfarm,
You are both right.
Tornado numbers have fallen, as mcfarm says but the number of tornadoes detected and spotted has been around the same, as shown by Tim's graph.
Hugh???
In the late 80's/early 90's the NWS spent something like a billion dollars installing NEXRAD doppler radars around the country to replace the 1950's vintage conventional radars.
These doppler radars can see and measure wind speed and direction........which enables them to detect tornadoes that the older units(which just show reflectivity of rain drops) could not see.
In previous decades, some weak tornadoes in rural areas were never observed or seen on radar and never got recorded as part of the statistic on Tim's graph. With today's very powerful doppler radars able to see these weak tornadoes better, more of them are being recorded. Also, many areas are more populated than in the past and the NWS has more spotters.
However, the violent tornadoes in the past could not avoid detection, often on radar with strong signatures(hook echos) and certainly with widespread damage on the ground.
It's these violent tornadoes that have become less frequent. Note on the graph below, how many more strong to violent tornadoes there were in the 50's-60's-70's than in the last 2 decades. Was there something different going on in those high violent tornado years?
Yes, global cooling!
Meteorology 101 tells us the reason. It's the meridional temperature gradient(contrast in temperature with latitude) that's most important. The bigger the difference in temperatures, the stronger the cold front, low pressure system and jet stream.
Those elements of weather systems are critical in contributing energy and favorable conditions for violent tornadoes to form(along with warm/humid air in place).
Notice though, that the always warm/humid tropics have tons of rain and thunderstorms but outside of those that occur with hurricanes(very rare events), they almost never have tornadoes.........because its too warm.
The contrast in temperature comes from cold air in the higher latitudes clashing with the warm air. Global warming and climate change has increased the temperature of the higher latitudes the most(Arctic for instance). This has decreased the difference in temperature between the, now slightly warmer high latitudes and the mid latitudes, that experience the violent tornadoes, when the cold air masses invade and lift the warm, humid air in place............and a powerful jet stream interacts in a way that induces a rotation.
It's likely that during the Little Ice Age, violent tornadoes were more frequent and during the Medieval, Roman and Minoan Warm Periods, tornadoes were less frequent.
Note that these periods have always been called WARM periods.......because history and people living in those times recorded many thousands of observations that indicated a much warmer climate than their ancestors had experienced.
So what about hurricanes?
Warmer oceans should theoretically cause stronger hurricanes, possibly a larger number of hurricanes, all things being equal. Is this happening?