Letter: Has global warming stopped?

Researchers have found that there was a slowdown of global temperature rise at the beginning of the 21st century, which is referred to as the global warming “hiatus.” This has led many to wonder whether global warming has stopped.

However, it is important to clarify that there are two things at play here: long-term trend and short-term trend. Long-term trend is the gradual warming we are seeing since carbon dioxide started accumulating in the atmosphere in 1850. Short-term trends could be due to events like volcano eruptions, El Niño, and La Niña.

The current “hiatus” is a short-term trend determined by drawing a line segment covering the period 1998 to 2014. However, the same exercise could be done to earlier records, and similar “hiatus” could be seen back then. This could lead to the conclusion that global warming stopped back then, which is obviously false.

Therefore, the recent short-term trend of global warming “hiatus” should not be confused with, and does not undermine the long-term, steady increase of the global surface temperature, which is the true global warming we should be concerned with right now.

This story was originally published June 2, 2016 at 1:59 AM with the headline "Letter: Has global warming stopped?."