Local Weather Still Not Global Climate

Climate change looks to be one of the major challenges facing humans in the 21th century and beyond. The evidence has accumulated to such an extent that we now can be reasonably confident that there is a current warming trend and that the human emission of greenhouse gases is a powerful contributing factor.

In fact, not only was April of 2016 the warmest April globally that has ever been recorded since measurements started, it is part of a 12-month streak of records. Yet, climate change denialism is alive and well.

There are thousands and thousands of newspaper articles, blog posts and social media groups that discuss global warming and climate change, yet people do not seem to be able to grasp the basic concepts of the field. One such prominent example is the difference between local weather and global climate. To put it simply, local weather is what you see outside the window, whereas global climate is long-term average trends for the entire world. NASA has a great article explaining the difference between weather and climate in additional detail.

Thus, it makes no sense to say that there is no global climate change because it was recently cold in some local area. Yet this is what climate change denialists and a lot of laypeople argue. In reality, it is as dumb as saying that there is no world hunger because you had a snack to eat last night or that because you no longer have a cold, infectious diseases must not be an issue globally.

Metro recently ran a story on the April 2016 global average temperature record and wrote down some of the commentaries viewers had written on their Facebook page. Granted, these might be especially selected because of their contrarian nature, but it is still worth going over them in some detail.

Ewa wrote (my translation):

Here it was cold

Well, it was warm only a few days at my place, otherwise cold all of April, like in the winter. Have been in Spain a week or so in April…warm and nice, but not more than 21 degrees.

Apparently, Ewa thinks that she can refute mainstream science and its global measurements by pointing out that it was cold near her home and not more than 21 degrees in a specific vacation location in Spain for one week.

Peter shares his thoughts (my translation):

Not a record

Wasn’t it a record in the world last summer too? Nothing that was noticed in Sweden, unfortunately. Hope we get to experience it this year.

Peter seems to think that another temperature record is nothing to worry about because that happened last summer too and he didn’t notice anything in Sweden.

Anne wrote (my translation):

Lived in a different world?

If this April is called heat record, I must have lived in a different world the last 30 years. Shit cold is what I call April 2016.

Anne thinks that April of 2016 was extremely cold and she uses her 30 year experience with local weather to back that claim up. No indication that she understands the important distinction between weather and climate.

Climate change denialists will protest and claim that a single warming record does not entail that we are in a warming period and that this itself is an example of the confusion between weather and climate. It is certainly true that a single record in isolation does not mean much, but a streak of records over a longer time periods does, and that is exactly what we observe. Years that have broken the record for average global temperatures in recent years are 2005, 2010, 2014 and 2015 according to the global 2015 analysis by the National Oceanic and Atmospheric Administration.

A great illustration of global warming can be seen in the animated temperature spiral by Ed Hawkings at Climate Lab book. Finally, one of the best resources for fighting climate change denialism is Skeptical Science that lists a large number of denialist claims with scientific refutations and references to the scientific literature.