(WLTX & Climate Central) - The earth is warming, but the observations show that not every place on earth warms uniformly. The data shows that the greatest warming to date has been in the Arctic region. There have been pockets of cooling yet, the entire earth taken as a whole is warming.
Recently the US Department of Agriculture (USDA) released its new zone map on plant hardiness. This is based on the average annual low temperature. All of the zones have been shifted poleward due to climate change.
The graph of the U.S. shows how the average low temperature of the coldest month of each year has changed from 1895 to 2010 in the U.S. as a whole. Some periods have been relatively mild, while others have have been cold, but the overall trend is toward warmer winters.
Unlike most states, however, South Carolina has bucked that trend (below), with winters actually getting a bit colder over that same period. It's a good illustration of the fact that global warming is an overall trend, but that some regions might cool, at least for a while.
Note on the two graphs that the 25 yr moving average has been going up since the late 1970s. It has warmed more nationally than for South Carolina. However, it was enough for the USDA to shift the plant hardiness zones northward after just 16 more years of data.