Thanks for the reply! I couldn't tell if you're agreeing, disagreeing, or trying to put forth an alternate theory here, but I'll adress some issues I have with your points.
Accurate temperature readings didn't start until the 1850's (1860's... 1850's..., close enough for this discussion), but general readings have been available since Galileo made the Thermoscope. Building cities around reading stations does not alter the data of thermometers, it alters the temperature of the earth's surface. The thermometers are still giving accurate temperature readings.
I have no issue with, but if I skip to #3, Eceny changes it to #2.
We have been reading and recording ocean temperatures around the globe since 1870, when the British launched HMS Challenger. I personally stuck a thermometer in the ocean before 1980.
New information does not automatically invalidate old information, and can be used to extrapolate much of the 'missing' data from older observations.
To learn how we determine temperature data for the vast majority of earth's history, do a search on geological temperature records, and biological temperature records.
Plants do indeed love CO2, which is one reason why I'm always trying to tell people to calm down with their global catastrophe talk. The predictions about the decline in food production as a result of human-created CO2 concentrations causing global warming... in my eyes they're nothing short of preposterous, and are based on opinions, not science.
Many plants, however, do not love UV radiation, and we may be getting a lot more of that as the magnetic field weakens, collapses, and flips. This is why I think it's a topic we should pay more attention to. I'm sure we'll still be able to make plants grow, but if we're not prepared to deal with the event, things could get really ugly.
I am agreeing with you.
Yes, they were doing ocean and Earth readings prior to the dates that I mention, but not on a regular wide-scale operation. Taking ship measurements while sailing is not the same as buoy measurements places throughout the ocean.
Potato, patato... the measure taken may be accurate, but it doesn't reflect the same location and conditions as previous readings, thus altering the validity of the data.
As far as the flip goes. I'm on the side of just a magnetic flip and not a stop of the Earth or a flip of the continents. Either way, there might not be any records of what really happened 10,000 years from now, just like then. ;)
Yes, UV radiation might not be kind to the plants. The increased cloud cover and cold temperatures will be less nice.