One of the challenges of discussing climate change is that it really is that bad. Completely realistic projections of things like sea-level rise, loss of agricultural productivity, and so on can sometimes sound like a disaster movie.

This is a bit of a problem in two ways. The first is that people naturally tend to dismiss possible future outcomes that they don't want to believe will happen. The second is that, since its predictions are for very negative changes, all of climate science has been branded "alarmist." In fact, if you do a Web search for "alarmist," the first results that aren't basic definitions or the Alarmist Brewery are all about climate change.

This week, however, we were provided with a number of indications that accusations branding all climate science as alarmism simply aren't true. In response to a couple of articles that were a tad overly pessimistic about our future, climate scientists have stepped in to provide a more realistic perspective about our future.

Science vs. New York

Over the weekend, New York magazine ran an article entitled "The Uninhabitable Earth." Its author, David Wallace-Wells, recognized that the numbers we normally talk about in terms of future climates are typically the median of likely outcomes. Although there's a chance that things won't be as bad as the median, there's also a good chance that they can be quite a bit worse. The premise of the article was to imagine if all the possible outcomes for our planet fell on the "quite a bit worse" side.

The premise was stated clearly, so the article was obviously going to have a negative outlook. That said, Wallace-Wells still managed to get a number of things wrong. For example, scientists recognize that the melting permafrost will probably release carbon into the atmosphere. But our knowledge regarding how much is still very uncertain. Even the most pessimistic view, however, doesn't suggest we'll liberate all of it, as "The Uninhabitable Earth" suggests: "all of it scheduled to be released at a date that keeps getting moved up."

The article mischaracterizes the result of a recent revision to temperature records as showing warming is happening "more than twice as fast." (For a more realistic take, see our coverage.) It says the minimum, or best case, we can see for sea-level rise is four feet by the end of the century (that's above the median of the IPCC's projections). The article even implies that a warmer climate will somehow foster the sort of genetic changes that have altered the Zika virus' symptoms (it won't).

The response by climate scientists has been pretty negative. Michael Mann, a scientist who has been frequently called an alarmist, posted a criticism online in which he noted some of Wallace-Wells' factual errors. But more generally, he said, "The article argues that climate change will render the Earth uninhabitable by the end of this century. Extraordinary claims require extraordinary evidence. The article fails to produce it."

Other complaints were lodged by scientists like Kevin Trenberth and Andrew Dessler.

It’s all academic

And scientists aren't limiting their push-back to stories in the popular press. Nearly a year ago, a researcher at Stanford published a paper in which she put together a record of the temperatures for the past two million years. She then analyzed it in a way that suggested that the climate's sensitivity to carbon dioxide was nearly triple the size of the IPCC's best estimate. That would mean the emissions we've already made would blow past the 2 degrees Celsius of warming that the Paris Agreement accepted. Instead, even if we stopped carbon emissions tomorrow, the paper suggested we'd see 5 degrees Celsius of warming.

We covered the paper (titled "Evolution of global temperature over the past two million years") when it came out, and other researchers didn't accept that conclusion. NASA's Gavin Schmidt and Penn State's Richard Alley both pointed out that the analysis assumed that all the warming involved in our glacial cycles comes from greenhouse gases. Instead, orbital variations and changes in the sunlight reflected back to space also play significant roles. The calculations in "Evolution," the scientists said, assigned all of the warming from these factors to carbon dioxide.

But Schmidt and Alley didn't limit themselves to talking to Ars. Today's issue of Nature contains a short comment by those two and 10 other climate scientists, pointing out the issues in "Evolution" in detail and using an extremely simplified climate model to highlight the role of the ice sheets themselves in modulating climate. And, as a result, the future warming from carbon dioxide has to be lower than the original paper's calculations.

(The author of "Evolution of global temperature over the past two million years," Carolyn Snyder, got the chance to respond to their criticism, and she strongly disagreed with it. But her response largely focuses on the proper way of calculating certain values and ignores the issue of whether those values can tell us anything about future warming.)

We asked Gavin Schmidt about the new paper, as well as the response to the New York article. "When people push back on mistaken assumptions or exaggerated claims, we are just doing our job," he told Ars. "We have to be objective."

While that means pushing back against alarmism, it also means pushing back against the people who argue that climate change doesn't pose a risk. "Claims that there are no problems are just as bad (and perhaps worse) than over-egged claims," Schmidt said. "To retain credibility, we have to tackle both. There are of course uncertainties in the science, but that neither means we know nothing, nor does it imply that anything goes."

Given that approach, it's somewhat ironic that criticizing the people who say there's little risk in climate change has probably led to him being labeled alarmist himself.

Nature, 2017. DOI: 10.1038/nature22803 (About DOIs).