The 2051 Fall meeting of the American Geophysical Union was witness to the inaugural Tessendorf Lectureship for contributions to the science of weather modification, awarded to Dr. Kay Rasmusdottir.

Thank you Dr. Holt, for that wonderful and thoughtful introduction. It is an honor to receive the inaugural Tessendorf Lectureship. I see many familiar faces in this crowd, and even more longtime friends. And it is in this spirit of friendship that I feel compelled to sound a bit of an alarm.

Yes, I see from your nervous glances, that this might not be what you were expecting. As the futurist and polymath Stewart Brand said, “We are as gods and might as well get good at it.” 

Given that this is the first Tessendorf Lectureship, I feel compelled — as we used to say — to go big, or go home. We stand poised at the precipice of foundational changes to the relationship of humanity and the physical world. Yes, of course people have changed and are changing the climate. That is not new. Nor are those changes complete or fully understood. But those are climatic changes, not changes to the day to day. The operational. The tactical. 

My heart has always been in understanding why the weather does what it does, specifically precipitation. Why do we get rain some days, and not others? Why does hail grow to the size of a grapefruit in some parts of the world?

I remember standing on the balcony of my home with my dad more than 60 years ago, hands on hips, and glowering at the lowering sky. It was pouring rain on the other side of the river valley in which we lived. The weather report had promised rain, and I had gotten myself ready to do some serious puddle stomping. I asked my dad why it wasn’t raining here, when the weather report told me it would. He said that weather reports couldn’t be 100% correct, and then — in a fashion typical of my father — launched into a thoughtful, detailed lecture on cloud microphysics. At six years old, I pledged then and there to figure this problem out. 

Now some six-year old pledges are as fickle as an afternoon shower. Mine was not. I have spent nearly every year since that conversation with my dad working toward better understanding our weather. Specifically, why it rains when and where it does — and just maybe how we can change that.

But I’m getting ahead of myself. 

After asking my dad how I could understand precipitation, he very sensibly said I would need to understand math, physics, chemistry, and a few other subjects. So like the type A person I am, I poured my entire self into my studies to understand the weather. Obviously I stood on the shoulders of giants here. Surprisingly, it wasn’t until my sophomore year of college that I asked a professor why we couldn’t just change precipitation, to fall where we wanted it to fall. The professor laughed, for a while. And then said the climate fiction class was in another department.

Embarrassed, I slid down in my seat in the lecture hall. But silently vowed to prove that professor wrong. By your laughter now, I think I may be among compatriots who vowed to prove their undergraduate professors wrong! Several years later, equipped with degrees in meteorology and physics, and graduate degrees in chemistry and atmospheric science I began an Assistant Professorship at the University of Washington. 

In the early 2020s I was able to sit as a bystander while ground breaking research was conducted by the National Center for Atmospheric Research on improving glaciogenic cloud seeding. Indeed, this lectureship is named for one of those groundbreaking scientists. Now, while that result was modest at best, the science was unequivocal. Glaciogenic cloud seeding had demonstrably worked. At the time, the shockwaves this should have sent through the community were quite subdued. The COVID19 pandemic, which stretched for years, the geopolitical unrest in Europe during the early 2020s, and the understandably-focused attention on climate policy all conspired to suppress interest in the weather modification revolution that was underway.

But that would soon change. 

In 2031 a drought engulfed much of the South American continent. A combination of a strong El Niño and below normal rainfall had led to very low soil moisture throughout the Chaco region of Argentina. Spurred by the successes of past weather modification efforts, the Argentine government authorized the use of precipitation enhancement. You may be familiar with the popular name of this phenomenon  — Andean Hell Hail. Which isn’t really fair, given that the cause of the hail was absolutely not the Andes but poor judgment on the side of some of the government decision-makers. 

The fall-out of this tragedy was immediate and catastrophic for the wine growing region of Argentina, which not only lost much of the crop, but saw much of the infrastructure and vines themselves destroyed. Science, however, learned an important lesson. Disaster alone cannot be the reason for action. Thorough understanding of the consequences of failure must be balanced against the desire to improve conditions. Of course this sounds reasonable to your ears, but it is a lesson, apparently, that society must repeatedly learn.

Let's move quickly past the COVID38 pandemic since that holds little but heartbreak, and past the Lusaka Carbon Accord of 2042 that was a much needed renewal of hope for continued global action on climate change. 

We now find ourselves in 2045. Who remembers why this year is important?

Of course you all know, as I see you saying the name aloud. The Black Sea Drought. Of course, the Black Sea was not at risk of drying up, but the breadbaskets in Ukraine were. All eyes were decidedly focused on this part of the world. And for very good reasons! Global grain supplies needed a boost and Ukraine was, and still is, central to global wheat production. So with food security on the line, the European Union convened numerous meetings about the safety and implications of cloud seeding. The scientific community had learned a tremendous amount in the intervening decades of how and why the Argentine disaster occurred. Central to the disaster were faulty assumptions about aerosol conditions aloft. These data gaps had been readily filled with innovations in high altitude, precision microphysics monitoring — innovations led in part by my research lab. 

I actually had a front row seat during the Black Sea Drought as I provided expert testimony on numerous occasions leading up to and following the events of 2045. While I could not advise — and still would not pretend — to have geopolitical wisdom, I was able to convey my confidence in our science. That is to say, that we could make a safe decision should an opportunity to seed the Ukrainian skies arise. 

Such an opportunity occurred in June of 2045, and we were granted permission by the EU to conduct the cloud seeding operation. With all eyes of the planet watching, we succeeded in manipulating those dry skies into producing rain. 

While we expected scientific approval, we did not realize what would then be set in motion. We had demonstrated in the open and transparently how cloud seeding could work. And it did work, in no small part due to enormous investments into basic research about the physics of the atmosphere as well as trust built among scientific groups and decision-makers. This has always been the slowest part of any sensible advancement in public science. But it is also the most necessary part. 

The surprise came when we realized that cloud seeding was effectively on the market now. Financiers looking to improve grain futures outlooks were finally convinced that cloud seeding was a good bet to improve quarterly profits. Despite a century of tinkering with weather modification, the definitive Live experiment of the Black Sea Drought transformed weather modification almost overnight into a field of wealth speculation. 

So, what do we as the scientific community do with this?

I realize that the purpose of this lectureship is to recognize leadership in weather modification, and as an apparent leader in this field, I have the following to say. 

In the past we had no control over the weather. Six year old girls would stomp, and stare at rainstorms that were supposed to fall on them, rather than across the valley. But now we have bottled this lightning. And we must now show restraint and precaution. Audacity and hubris are uncomfortable bedfellows, so we must find a way to navigate safely between the two moving forward.

I am grateful for the chance to perform so much exciting and rewarding science over the past many decades. I find myself now, behind this lectern, calling on the weather community to consider whether we should continue pursuing this science, or more clearly reckon with whether a moratorium should be placed on this technology until more can be understood.

It is unlikely that I will be making any more groundbreaking discoveries. But I see many young faces in this audience. Faces that are the future of this science. And it is in you that I put my trust and hope that we can be responsible stewards of this world.

Thank you very much for your time tonight.