Trees are emitting a lot less carbon dioxide as a result of warmer surface temperatures than previously believed, according to new research published in the journal Nature. Though they absorb carbon during photosynthesis, trees also release some carbon back out into the atmosphere in a process called respiration. Climate change was supposed to make that respiration process a much bigger problem, but this new study brings us positive climate news, for once. The New York Times reports:
Until now, most scientists have thought that a warming planet would cause plants to release more carbon dioxide into the atmosphere, which in turn would cause more warming.But in a study published Wednesday in Nature, scientists showed that plants were able to adapt their respiration to increases in temperature over long periods of time, releasing only 5 percent more carbon dioxide than they did under normal conditions.Based on measurements of short-term temperature responses in this study and others, the scientists expected that the plants would increase their respiration by nearly five times that much.
The overwhelming majority of climate news can be filed under the “doom and gloom” subheading, so it’s worth noting when we learn of a natural system being more resilient than expected. Prior to this study, scientists anticipated trees would respirate five times as much carbon dioxide than what these researchers found. That’s a big downward revision for an important source of carbon emissions—the NYT points out that plant respiration “contributes six times as much carbon dioxide to the atmosphere as fossil fuel emissions.”It also illustrates that our understanding of our planet’s climate, and of the countless systems that contribute to and are affected by changes in that climate, is far from complete. We know that our climate is changing, that greenhouse gases are driving these changes, and that humanity is responsible for many of these emissions. Beyond that, though, climate science is riddled with mysteries. The system researchers are studying is bafflingly complex, replete with variables known and unknown that interact with one another in ways we don’t fully comprehend.Greens would have you believe we’ve fully diagnosed the problem and can see what’s coming next, but time and again climate models have gotten their predictions wrong. By exaggerating how settled the science is, environmentalists are setting themselves up to look foolish when we find our best understanding wasn’t good enough. They become the leading source of climate denialism.These models can be useful tools, but not if we place too much faith in them, and not if we don’t continue to fine tune as we discover new truths about the way the world works. This isn’t the first time scientists have been surprised by a component of climate science, and it won’t be the last—but at least this time it comes as heartening news.