Yes, Joyce, what you describe is exactly what you would expect with global warming/climate change, at least in the oscillating stage. The seasons are actually changing too. Spring is earlier and this certainly confuses plants and animals. And no, oranges won't grow where there are record highs followed by record lows, with alternating droughts and floods and high winds. Nor will the Canadian prairies be improved by this, particularly if they begin to get -70 winter temperatures as the Siberians are experiencing now. (The fires caused by the burning of the defrosted tundra will make Canadians pretty miserable, too.)
Who is to say there is global warming? Well, the Intergovernmental Panel on Climate Change, made up of the world's top climate scientists, found in 1995 that not only are we experiencing global warming/climate change but it is caused by fossil fuel burning.
I am from southern California and the Santa Barbara Channel has a 160,000-year history of the earth's climate fluctuation in its sediment, which has been analyzed by university scholars whom I have interviewed.
IPCC scientists are not ignorant that we are in the Holocene, a 10,000 year overall warming period (though it was quite cold about 3,000 years ago) nor are they ignorant of the "Little Ice Age" that occurred in the 14th century and had such an impact on Greenland (probably as a result of atmospheric alternation, that is, volcanic activity, not caused by humans).
What is significant about the present warming period is that it is accelerating beyond what would be expected and in fact contrary to what would be expected; that can be realistically explained only by the 6 billion tons of CO2 and other fossil fuel byproducts that are added to the finite atmosphere yearly. IPCC scientists are certainly well aware that there have been other climate eras during the earth's history and that only 120,000 years ago temperatures overall were hotter than we have at this time. There have been many climate swings and fluctuations not caused by human beings (usually followed by a large climate shift taking place within a 50-year period).
What is significant here is that 1. It is happening now in our lifetimes 2. Humans are causing this one 3. There are things that fruit explorers can do to influence it (not necessarily even stop it) 4. There are things fruit explorers can experiment with in adapting to it, including sharing our experiences.
Jolon at Last Farm
USDA Zone 8/9