Policy / Science

The ‘hiatus’ that never was

Let’s start off with a little game of good news, not-so-good news. First, some good news: a recent survey released by the nonprofit foundation ClearPath reveals that the majority (~56%) of Republican voters, and even many of those that identify as conservative Republicans (~54%), accept that the climate is changing and that human activity is contributing to this change. Surprised? I was too. Watching the last two primary debates and hearing the claims being made by many of the presidential candidates, it’s easy to forget sometimes that their mind-bogglingly silly assertions may not represent the majority of the voter base. Hence, the not-so-good news. That is, there are still a significant number of politicians that refuse to board the climate change train, and their stubbornness is preventing any sort of meaningful progress on this issue.

This brings me to the main topic of this post. For the past several years, climate scientists have been perplexed by what appears to be a sort of ‘hiatus’ or slowdown of the rapid rate of atmospheric warming during the 21st century that has occurred while carbon emissions have continued to increase. Some researchers have attributed this to the irregular uptake of heat by the oceans, others have explained it as a shortsighted look at a long-term trend, and of course many politicians have used it as a leverage point to refute humanity’s role in climate change. However, a new study conducted by a research group at Stanford University confidently shows that scientists have been on a wild goose chase to explain a ‘hiatus’ that does not actually exist.

Credit: Scripps Institution of Oceanography

Credit: Scripps Institution of Oceanography

Using the three most reliable global near-surface temperature records, the team meticulously worked through four distinct, statistically testable hypotheses to understand exactly what has occurred in the climate over the past 15 years. They examined, (1) whether the trend in global temperatures is no longer increasing, (2) if the rate of warming has simply slowed down, (3) whether the annual mean global temperature has remained the same, and (4) whether there has been a difference in year-to-year temperature changes in the last 15 years, compared to the preceding 50 years. And after accounting for and controlling potential biases in a number of statistical frameworks, their conclusion to all of the above hypotheses is a clear and undeniable NO. Their results show no statistical evidence to support that a ‘hiatus’ in global warming has even occurred, and instead demonstrate that “the evolution of global surface temperature over the past 1-2 decades is not abnormal or unexpected within the context of the long-term record.”

But alas, I can already hear the grumbling political skepticism. Why haven’t any of the thousands of climate scientists realized their statistical oversights until now? How do we know that these researchers didn’t just use this complicated mathematical jibber jabber to prove what they want to be true? In my opinion, the most cogent argument for those of us who don’t understand the intricacies of the statistical methods (which includes me and undoubtedly every politician in Washington) is the simple fact that we are able to put our faith in mathematical and statistical experts in virtually all other areas of our lives. The technologies we use, the medicines we trust, and the economic frameworks in which we do business are all developed using the same levels of mathematical complexity.

The difference of course is that the science underlying these other matters is easily validated by observation. If NASA builds a new rocket and determines a trajectory to land it on Mars, we’ll be able to figure out pretty quickly if the mathematical calculations and assumptions were accurate. If GoogleMaps directs us to the Eiffel Tower instead of to the grocery store where we wanted to go, we can clearly see that the algorithms it used were inaccurate. Unfortunately, when we’re talking about proactively addressing environmental concerns, 2012_06steingps600we don’t have the luxury of waiting one hundred years to confirm by observation that the statistics are correct. Instead, we have to rely on scientific consensus to corroborate the findings of individual research results. This is the foundation of the peer review process and the very thing that many politicians fail to appreciate. The fundamentals of global warming have stood up to a level of peer review more rigorous than almost any other environmental phenomenon to date. Yet even with the wholehearted endorsement by our President and over 97% of the scientific community, the political debate, at least in this election, has been kept very much alive.

My hope is that people will begin to read arguments like this and roll their eyes because it’s no longer a question. And if you take a look through the entire survey I mention above, I think the results are a really promising sign that this may finally be happening. It appears that the American populace is beginning to accept that our negligence is having an undesirable impact on our global environment and that the benefits to proactive management are wide ranging. We can only hope that politics is not far behind.

And now, a musical piece that transforms 133 years of global temperature data into a composition entitled, “A Song of Our Warming Planet”:

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