News from a Changing Planet – #3
The first image of Earth from space, “Earthrise,” taken on the Apollo 8 mission on Christmas Eve, 1968, is so familiar and famous and ubiquitous that it’s hard to imagine a time when we didn’t know what Earth looked like from the farther reaches of our galaxy.
Earthrise, taken by William Anders.
(This photo, coincidentally, was a symbol for the environmental movement that I wrote about in the first newsletter.)
This week, we mark the 50thanniversary of the Apollo 11 mission, the first spaceflight to put humans on the moon. “One small step for (a) man, one giant lap for mankind,” etc., etc., you’ve heard it before.
(There may come a day where every other edition of this newsletter is not about a 50thanniversary of something, but today is not that day).
On this anniversary, we are celebrating lots of things – American achievement, daring, ingenuity and innovation. And we should also be taking the time to remember the context in which the Apollo 11 mission took place. Like today, American society was full of rifts and fissures along racial, regional and sectarian lines. The mission to put a man on the moon wasn’t always popular, historians report, and many Americans were troubled by the contradictions: how could the government be dedicating so many of its resources to the moon and to space when Americans were dying in Vietnam, or risking their lives for racial equality and justice at home?
It is important to remember all of those things, and to be an American, you have to learn to live with the contradictions and complexities in our history. And I am not putting those things aside.
But I want to talk a little today about a somewhat overlooked legacy of the Apollo program and the massive investment in NASA itself that the program demanded in the 1960s. It is because of NASA (and the efforts of other space agencies) that we know that the climate is changing; it is because of NASA that we know how it’s changing, how all of the changes interact with each other, how the climate will change going forward, and what all of those changes might mean for life on earth for future generations.
I recently was able to attend a lecture by Dr. Michael Freilich, the former director of the Earth Science Division in the Science Mission Directorate at NASA Headquarters, about climate change and NASA’s leadership on the science of our changing planet. Most of this information comes from him, and you can watch the lecture here.
Because of NASA satellites and the devices placed on them we can measure the amount of carbon dioxide in the atmosphere every two weeks, and see how the earth is breathing.
Atmospheric carbon dioxide levels, June 1, 2015 - June 15, 2015
Precision instruments on satellites can measure sea level rise from 1600km above the earth’s surface, on the order of a couple of centimeters, and tell us that on average sea level is rising by 3 millimeters per year around the world. It’s because of those instruments that we know that 2 of those 3mm are the result of sea levels rising, and 1mm is the result of the heating of the upper ocean (liquids expand when they get hotter).
We can measure sea ice loss at the poles, and the thickness of sea ice from year to year. Those measurements can help us understand what the climate might be like going forward, and tell us if and when we move from a global climate that is governed by the oceans to one that is governed by the atmosphere (what scientists call a tipping point).
Minimum Arctic sea ice extent, September 2018, 6th lowest on record
Decline in multiyear sea ice coverage.
We can measure the amount of freshwater on earth, the reservoirs in underground aquifers, global precipitation, the structures of storms, soil moisture, sea surface salinity, and the global processes that tie all of these measurements together.
Lake Mead, Nevada. (The gray-ash pixelated cluster on the left side of both photos is Las Vegas.)
And from all of these measurements, we can extract meaning about life on earth -- specifically, human life on earth -- and how it will be changed by what we are doing to the planet -- burning up underground reservoirs of carbon dioxide, paving over the planet, blasting the tops off mountains, sucking the water out of the ground and poisoning what's left, I could go on.
A recent review of several books commemorating the 50thanniversary of the moon landing appeared to take issue with the entire endeavor to go to space, and argued that our obsession with the technological achievements made possible by the Apollo program has made us lose sight of its true legacies: “the joy of knowledge…the wisdom of beauty and the power of humility.”
The review ended by saying that the Overview Effect – the feeling of seeing Earth from above, like “Earthrise,” but in real life – which astronauts say changed their view of earth, is not enough, particularly in light of the climate crisis: “Saving the planet requires not racing to the moon again, or to Mars, but to the White House and up the steps of the Capitol, putting one foot in front of the other," the review stated.
I disagree. While I am skeptical of the claims of some tech billionaires about why they want to go to space, and I wonder if they couldn’t use some of their ingenuity and capital and engineering power to work (harder) on the climate crisis, there is clearly so much that we have learned and will learn about earth from space that few could have anticipated, certainly not in specifics.
To somehow suggest that climate change is important while space exploration is a distraction is to disentangle their histories. The idea that we could have the knowledge of one without the existence of the other betrays a lack of respect for science that we more often see from those who deny climate change itself. Who knows what we will learn from future missions to the moon, or Mars or farther reaches of the galaxy?
According to Dr. Freilich, "The greatest uncertainty about climate change is not our lack of understanding or of measurements; it is the policy choices we will make."
Without NASA and other global space agencies, we wouldn’t know that we had a choice.