You may have heard about reports a few years ago that there had been a pause in global warming during the 1990s and possibly into the 2000s. Last week there was a report from scientists at the National Oceanic and Atmospheric Administration (NOAA) that the pause was not real, but the result of measurement errors. Unfortunately, these types of information tend to have the effect of making people not believe scientific results, especially people who don't want to believe them.

I'd like to help those of you who aren't scientists better understand how we scientists approach problems and how these changes of results can occur.

After a question is posed, such as how has the temperature changed over the last 100 years, we search for the best measurements that we can find. Because of technological advances, these measurements become more precise over time. So, comparing measurements from 1900 to those from 2016 is difficult. Let me just state that we do the best we can. Our results are submitted to peers, whose job it is to find an error in our work. If they find no error, the results are published. The results then become fair game for any other scientist to find an error, and we take great pride in doing a better job than our colleagues. So, one of my jobs as a scientist is to read what my colleagues have done and see if I can do better, i.e. find an error in their results. After we confirm our measurements, we then must answer the question why did I get that result. This usually means using computer models with basic physics to match the observations. When the measurement results change due to better research, we again must answer why. In many ways it is an unending game, do better than the other guy.

The next part of the issue is what exactly causes a change in results. Most frequently it is a consequence of better instruments with more precision. Or, it can be a result of how the measurement is made. Another problem with the "pause" was that computer models could find no physical reason as to why it should have occurred. Thus scientists needed to go back and take a more careful look at the "pause" data. In the case of the most recent temperature error, it has been found to be a matter of measurements made from ships and others made from buoys. After careful study of the data, it was determined that ships systematically measured higher temperatures. It was even determined why. After corrections for ship measurements had been made, it was determined that there was no pause.

So, the question for the non-scientist who has to live with our conclusions is, what should we do. We scientists can pretty confidently say that there is global warming and it is a result of human activity. We can suggest solutions, such as reduce carbon output. We can even suggest how to do that. However, it is up to society as a whole, not just scientists, to decide what risks we should take and what actions we should and shouldn't take. This means we need to have an informed and thoughtful population or at least leaders who have these qualities.