This is just one of dozens of responses to common climate change denial arguments, which can all be found at How to Talk to a Climate Sceptic.
Objection:
Some stations, in the US for example, show cooling trends. If there really were global warming, it would be warming everywhere.
Answer:
Global Warming refers to the long term increase in globally and seasonally averaged surface temperatures. It is not the case, nor is it expected, that all regions, let alone all weather stations, on the globe will show the same changes in temperature or rainfall patterns. There are in fact many stations that have shown cooling, and some small regions have also shown modest cooling. This is not a contradiction that invalidates global warming theory, it is merely the result of regional variation and an example of how varied and complex the climate system is.
The contrarian website, CO2 Science, makes this fallacious argument part of its homepage by featuring a "Station of the Week" that has exhibited trends differing significantly from the global one. Given the effort and technical content of that website, and the fact that they prominently display this intellectual sleight of hand, I think it is safe to say that they are simply being dishonest.
All of the various global temperature trend analyses agree that the average temperature is showing significant warming.
These analyses agree with the expectations of climate theory, as well as all the other lines of evidence.
This is just one of dozens of responses to common climate change denial arguments, which can all be found at How to Talk to a Climate Sceptic.
“Some Sites Show Cooling” was first published here, where you can still find the original comment thread. This updated version is also posted on the Grist website, where additional comments can be found, though the author, Coby Beck, does not monitor or respond there.