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The Climate Story Nobody Talks About

Earth as seen from the moon. i
NASA
Earth as seen from the moon.
NASA

On Nov. 30, world leaders will gather in Paris for a pivotal United Nations conference on climate change.

Given its importance, I want to use the next couple months to explore some alternative perspectives on the unruly aggregate of topics lumped together as "climate change."

There is an urgent demand for such alternative narratives and it rises, in part, from the ridiculous stalemate we find ourselves in today. But the endless faux "debate" about the state of climate science also obscures a deeper — and more profound — reality: We've become a species of enormous capacities with the power to change an entire planet. So, what exactly does this mean?

In service of answering this question and looking for perspectives on climate change beyond the usual focus on controversy, let's begin by acknowledging a single fact that's rarely discussed in the media: Climate science is a triumph of human civilization.

Landing on the moon. The development of relativity theory. The discovery of DNA. We rightfully hail these accomplishments as testaments to the creative power of the human imagination. We point to them as the highest achievements of our species, calling them milestones in our collective evolution.

But climate science is no different. It, too, belongs in that short list of epoch making human efforts.

Here's why: Just two centuries ago, humanity barely understood that a planet's climate could change at all. People were still digesting the idea that Earth was a whole lot older than 6,000 years. But by the 1870s, most scientists accepted that our planet had experienced prolonged climate shifts — in the form of ice ages — dating back tens or hundreds of thousands of years. Explaining the causes of the ice ages was, however, far beyond the capacities of science at the time. That meant humanity would have to build those capacities.

Across the latter half of the 20th century, an effort worthy of multiple Manhattan Projects unpacked something entirely new and entirely remarkable: a science of planets in all their complex glory. Wind, oceans, ice and rock: All of it had to be accounted for if the story of Earth and its climate was to be told.

But we couldn't tell Earth's climate story without understanding climate on other planets, too. That's why it's no accident that climate science came to maturity in the space age.

This is the first point to understand. All the effort and all the genius poured into humanity's bold exploration of the solar system have found their deepest expression in the science of climate.

So, what exactly did we win in this decades-spanning work? What did we learn about planets, their atmospheres and their evolution? To answer these questions, let's start with the solar system and work our way back home.

David Catling, a professor of Earth and space science at the University of Washington in Seattle, gives us the 10,000-foot view:

"Before the 1960s, people entertained ideas that Venus might be a balmy, humid world and that Mars might be covered in vegetation and crawling with Martians. A major achievement has been gaining accurate knowledge of these atmospheres by sending out spacecraft which have revealed planetary [climates] weirder than anyone imagined."

For a specific example of climate science's reach and power, Tony Del Genio, a researcher at NASA's Goddard Institute of Space Studies, points us to Titan, the haze covered moon of Saturn: "I think a really impressive feat is how climate models helped explain the polar [liquid methane] lakes on Titan."

The models Del Genio refers to embody all that climate physics and chemistry scientists have learned over the last 60 years. When they were applied to Saturn's remarkable moon, the presence of lakes at high latitudes (rather than at the equator where scientists expected they might occur) were cleanly seen to be a natural result of circulation on a slowly rotating body like Titan with very long seasons.

But, it's Venus that's the real poster child for climate science triumph, extra-terrestrial or otherwise. Even though it's about the same mass and size as Earth, temperatures on Venus hover around 860 F (hot enough to melt lead) and there is almost no water anywhere on the planet. Venus is as close to hell as you'll find in this solar system — and its location closer to the sun does not, by itself, explain it's terrible state.

So, what happened to Venus?

Jim Kasting of Penn State explains, "Climate models predict that an Earth-like planet (one with lots of water on its surface) will develop a runaway greenhouse at a solar flux somewhat larger than that of Earth."

In other words — with our modern understanding of climate — we now know that if Earth were placed in Venus's location, the greenhouse effect would go nuts, heating the planet and driving water molecules high into the atmosphere where sunlight zaps them apart. What's left is a hot, dry atmosphere composed almost entirely of CO2. That's a runaway greenhouse effect. "There's good evidence this happened on Venus," says Kasting, who points to detailed chemical analysis of the Venusian atmosphere that proves the water was lost to space.

Venus, Mars and Titan — while many exciting questions are still to be answered about these worlds, the basic science of climate on these alien planets is now understood. That certainly sounds like a triumph of human civilization to me.

Now, let's return to the climate of our own blue world. Catling can easily tick off a list of terrestrial climate science's epoch-making achievements. There's the development and deployment of a global monitoring system for the planet. "A major achievement of modern civilization," Catling says, "is the continuous satellite monitoring of the Earth's weather, climate and atmospheric composition, in combination with thousands of monitoring stations on the surface." Then, there's exhaustive work measuring molecular properties of atmospheric gases to understand how they interact with both sunlight and heat radiation emitted by the Earth. One also can point to the development of high performance computer simulations of planetary climate. "The advances in computing to solve the physics and chemistry of the atmosphere cannot be overstated," Catling says, pointing out this advance led to huge increases in weather prediction accuracy.

More than anything, however, the real triumph of climate science comes in its ability to understand what's happening to the Earth now. Del Genio describes it in the simplest of scientific terms:

"The major achievement of terrestrial climate science is that 34 years ago, Jim Hansen and colleagues published a paper in Science making the first prediction of the rate of climate change over the next few decades as a result of CO2 increases [see Figure]. Looking at how much the Earth's surface temperature has actually changed in that time, they came remarkably close. That was a true prediction of the future, and sufficiently long ago that we have the chance to see how good it was."

Climate Theory Ca. 1981 Vs. Climate Reality Now

Global temperature variations compared with a paper published by climate scientist James Hansen and collaborators in 1981. The Hansen model used computer simulations that were crude by today's standards but, as this figure shows, did a pretty good job of predicting the increase in global temperatures over the next 34 years. Note that the Hansen et al predictions actually underestimate the amount of global warming. From the abstract of the paper: "It is shown that the anthropogenic carbon dioxide warming should emerge from the noise level of natural climate variability by the end of the century, and there is a high probability of warming in the 1980s."

Chart

Prediction and validation: We once were blind and now we see.

We once saw planets as nothing more than wanderers in the night sky. Now the patterns in their winds and their flows of water — or other liquids — are known to us. We see clearly enough to understand. We understand clearly enough to predict. This monumental transition was hard-won, costing many human lives, millions of hours of effort and billions of dollars of wealth. From thousands of buoys scattered across the ocean recording sea surface temperature to satellites orbiting high overhead monitoring heat radiation, we humans invested our genius to built the capacities and achieve the impossible.

We learned to read entire worlds.

No one can take that achievement from us. We are greater for what we have built with climate science — and with that greatness we can be greater still.


Adam Frank is a co-founder of the 13.7 blog, an astrophysics professor at the University of Rochester, a book author and a self-described "evangelist of science." You can keep up with more of what Adam is thinking on Facebook and Twitter: @adamfrank4.

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