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Climate change is here

In his recent opinion piece “Musings of a climate-change skeptic,” Paul Hoffman greatly minimizes the risks associated with climate change and greatly oversimplifies the science associated with assessing and addressing those risks. In short, Hoffman’s description of climate change science and the process of science that has led to our current understanding of climate change are deeply and irrevocably flawed.

Understanding the changes that humans are making to the Earth’s climate has been, and continues to be, one of the largest investigations into the Earth’s function in all of human history. This effort has demonstrated that human activities are changing the Earth’s climate, putting political, economic, social, and natural systems at great risk.

In Hoffman’s piece, he mentioned that he graduated from UC San Diego’s Revelle College. Hoffman is likely aware that Revelle College is named after Dr. Roger Revelle, who is best known for his work as an oceanographer. While at the Scripps Institution of Oceanography in California Revelle aided in some of the first continuous measurements of atmospheric carbon dioxide. In the 1950s, his work demonstrated that carbon dioxide levels in the atmosphere were rising due to the burning of fossil fuels and suggested that the oceans could not absorb the extra carbon dioxide. In short, Dr. Revelle’s work was some of the earliest work to quantitatively demonstrate human-caused climate change.

The climate system is incredibly complex. With the advent of satellites collecting data and increasingly powerful computers running highly sophisticated climate models, we have learned much since the 1950s. While our knowledge is much deeper now, the most basic principles of climate change put forward decades earlier remain unchanged.

So what does this mean? Well, Hoffman stated that scientists are naturally skeptical. How right he is. So that means that the basic tenants of climate change have been tested and re-tested over and over again by these skeptical scientists. They’ve been poked and prodded, looking for any weakness, any evidence that something is wrong. And guess what? Those core tenants, decades later, are still here. They have survived the assault. In fact, it’s not simply that no one can suggest otherwise, it’s actually that our understanding of the changes to the climate system, as well as our level of confidence in those changes, has increased over time. This is scientific consensus.

Science is not simply an individual deciding what is true or not true in the natural world. Instead, it is a community of peer experts publishing findings in scientific articles and presenting research at professional conferences. These articles and conferences are the communication tools of science (much different from how we communicate in the general public day to day) and this collective communication overwhelmingly supports climate change.

As summarized by the Intergovernmental Panel on Climate Change’s Fifth Assessment Report (https://www.ipcc.ch/report/ ar5/),

“Warming of the climate system is unequivocal, and since the 1950s, many of the observed changed are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, and the sea level has risen … Anthropogenic greenhouse gas emissions have increased since the pre-industrial era, driven largely by economic and population growth, and are now higher than ever. This has led to atmospheric concentrations of carbon dioxide, methane and nitrous oxide that are unprecedented in at least the last 800,000 years. Their effects, together with those of other anthropogenic drivers, have been detected throughout the climate system and are extremely likely to have been the dominant cause of the observed warming since the mid-20th century.”

This is an example of consensus science. The above statement was only written after decades of scientists from all over the world collecting data, testing, experimenting, and modeling everything from the atmosphere itself, to its complex interactions with the ocean, biosphere, and lithosphere.

Are there questions that remain unanswered? Most definitely. Is there uncertainty in any scientific endeavor? Absolutely. But the climate scientists, geologists, ecologists and many other scientists working on climate change are only becoming more convinced, not less, of our role in climate change. This is not to demonize human beings, but rather to make available the best information to reduce the risk of climate change to human and natural systems. We cannot address each of the scientific points that Hoffman asks us to “consider” in his article, but none of them are unconsidered by current climate science. In fact, all are addressed in the Intergovernmental Panel on Climate Change report referenced above.

Climate change is not a future phenomenon. Climate change is here and now. For example, work performed by scientists at World Weather Attribution (https://www. worldweatherattribution.org/) demonstrate that the European heat wave of this summer is more likely today due to human-caused climate change.

Finally, Hoffman paints, with a broad brush, scientists as guided by political ideology (presumably a liberal one) and “pre-determined outcomes.” These are serious ethical accusations that Hoffman fails to provide an ounce of evidence to support his claim (in fact, evidence is curiously missing in all of Hoffman’s article). As in any profession, there are certainly people guided by self-interest. However, the vast majority of people we work with are good and decent people. We went to graduate school with a passion for our disciplines and a desire to make our communities better places to live. Climate change is a “wicked problem” – one that is almost incomprehensibly complex, incomplete in its understanding, and yet requires immediate attention. While the science is most certainly complex, that’s actually not the hard part of climate change. There is one question that we as scientists can’t seem to get a good handle on. What are human beings going to do about it?

This column was co-authored by Christopher F. Labosier, Ph.D., Assistant Professor of Environmental Science, Dina M. Leech, Ph.D. , Associate Professor of Biology and Kenneth Fortino, Ph.D., Associate Professor of Biology, all of Longwood University. For questions or comment email at labosiercf@longwood.edu.