Greetings from the Climate Strike

 This photo is from Greta Thunberg's Facebook page.

This past Friday, September 20, 2019, a youth-led climate strike took place in cities across the world.  Several million people globally, including up to a quarter million people (according to organizer estimates) in New York City, took to the streets to demand that world leaders respond to climate change and global warming with the urgency that science indicates is necessary.  As one of the massive army in New York, I was impressed and inspired by the energy of the protesters and their optimism in their own ability to make change.  But as an atmospheric scientist who has been studying the physics of climate for longer than most of my fellow protesters have been alive, I felt a tinge of sadness that it had come to this.

As sixteen-year-old Swedish activist Greta Thunberg pointed out in her speech to the United Nations on September 23, "For more than 30 years, the science has been crystal clear.”  The climate science community have gathered quite a bit more data since Dr. James Hansen’s 1988 visit to the U. S. Senate made “global warming” a household term, but the data have reinforced the conclusions, not altered them.  The Earth is getting warmer, at a rate which cannot be explained by any known natural cycles.  It can be largely explained, however, by the rapid, steady increase in atmospheric concentrations of carbon dioxide, instigated by the burning of coal and hydrocarbons for energy and aggravated by the loss of forests which serve as the Earth’s primary natural “sink” for the gas.  This is because carbon dioxide absorbs the kind of infrared radiation that the Earth emits, so that the energy contained in that radiation stays in the atmosphere and does not escape into space.  This warming will have consequences, including rising sea levels, stronger storms, and longer and more deadly heat waves.  And the cost of accepting these consequences will be far greater than the cost of preventing them would be.  None of this is new.  None of this is even up for debate on the grounds of reasonable doubt.  And yet, for as long as I've studied atmospheric science, I’ve felt that I was banging my head on a brick wall every time the subject came up in conversation.  I’m not sure that I’ve changed the mind of even one of my skeptical friends and relatives.  And people who have no interest in even acknowledging the existence of global warming, much less doing anything about it, continue to win far too many elections.  But young people have begun to realize that the consequences of global warming will affect them more than they will affect people my age, and they have started listening.  As Thunburg told Congress last week, “I don't want you to listen to me.  I want you to listen to the scientists.”  It would have been self-defeating, on many levels, for me NOT to go and lend my support.

The quote on the poster is from Dr. Seuss's "The Lorax"

I decided to wear a T-shirt I have that says “Ask me a question, I am a scientist.”  I got that shirt volunteering at the Long Island Mini Maker Faire in Port Jefferson, NY this past June.  As I said when I started this blog, one very useful thing we can do as individuals to combat global warming is simply to talk about it, in order to raise awareness and improve understanding.  I figured that shirt would be a good conversation starter.  And indeed, both before and after the march, I had a number of people come up and ask me questions.  Most of the questions were some variation of, “How screwed are we?”  That's not an easy question to answer, because how the Earth looks a century or two from now will depend quite a bit on our actions in the meantime.  The present politically-established benchmarks are not adequate to prevent massive long-term damage.  The Paris Agreement talks about limiting warming to 1.5°C above pre-Industrial levels. But the last time the Earth’s temperatures were as warm as they are now (about 1ºC above pre-Industrial level) for a significant length of time, sea levels were 20 to 30 feet higher.  And the last time levels of carbon dioxide in the atmosphere were as high as they are now, sea levels were 50 to 60 feet higher.  That's the world our descendants would inherit if the current temperature or carbon dioxide level is maintained for a century and beyond — but of course we’re nowhere near leveling off anything.  The good news is that it doesn't have to be that way.  Clean energy is cheaper right now than most people realize, and the technology is improving and will continue to improve if politics allow it.  But, consequences are happening right now.  Sea levels have risen about 8 inches on average globally since the late 1800s, and about a foot in New York City.  That foot mattered when Superstorm Sandy hit my area in 2012.  And those extra inches mattered in the Bahamas this past month when Hurricane Dorian hit.  So did the increasing intensity of hurricanes — the Atlantic used to see a category 5 hurricane once every three years on average, but this is the fourth straight year we have seen one.  As of September 23, 53 people are confirmed dead because of Dorian, but over 1000 are still missing.  And the fierce heatwave in Europe this summer killed 1500 people in France alone.  It didn’t have to be that many, and yet that won’t be the worst heatwave that young or even middle-aged people in France will live through.  The rate of sea level rise has begun to accelerate, and is projected to accelerate further.  It may take a while to level off, even if we do start to act decisively; a just-published paper by a former colleague of mine concluded that it would take twenty years to slow down (much less stop) the rate of temperature increase even with a quick phaseout of fossil fuels.  And temperatures will have to go down before sea level rise can be reversed.  So lives hang in the balance right now, and the number of people killed, or displaced, or pushed from the category of people who “have” to people who “have lost,” will grow and grow.  Unless.

Taken from this article.

From Greta Thunberg's Facebook page.

Here on Long Island where I live, I have friends who write and sing children’s music.  My favorite song of theirs, titled “One Drop in a Bucket,” talks about how one seemingly small action can cascade into something much larger.  I wonder if Greta Thunberg, when she first showed up outside the Swedish Parliament on a Friday last August carrying her now-iconic poster, had any idea that millions of children would eventually join her.  Or that her simple action would be chapter one in a Tolkienesque quest that continues for her thirteen months later.  But that’s what happened.  For the first time in my professional life, I know that there is a large group of people who take the issue of climate change and global warming as seriously as it needs to be taken.  And to those people I can only say, “thank you.”  I’m sorry it has been left to your generation, and I take some responsibility for the fact that we have not done enough, nor have we really tried.  But I’m still here, and I promise to keep banging my head on as many brick walls as I come to, for as long as it takes.

(For updates on new posts, please click the "Follow" button.)