Dr. Meridian Northward works at the Northern Temperate Disease Modeling Consortium, where she creates predictive maps showing where vector-borne diseases will spread over the next 25 to 50 years. Her 2024 projections for Lyme disease expansion into Atlantic Canada have been widely cited in public health planning documents.1 When I arrive at her office, she's surrounded by maps covered in colored zones representing future disease endemic areas. She's using a red marker to cross out dates on one of them.
"These were for 2045," she says, not looking up. "But that was last year's model."
Your recent projections show Lyme disease moving into Atlantic Canada by mid-century. What does that timeline mean now?
The mean centroid shift for vector-borne diseases in northern temperate areas is 0.87 degrees north between 2030 and 2080.2 About 96 kilometers at the equator, if you're keeping track. Which I am. Was.
But which question am I answering? The one about what the timeline means, or the one about whether timelines mean anything anymore? Because shouldn't someone who makes thirty-year forecasts know the difference? Don't you think I should be able to tell you which question you actually asked?
Let's start with whether you still believe your own projections.
Believe? What does belief have to do with modeling? The data shows consistent poleward range shifts across zoonotic and vector-borne diseases. Longer warm periods expanding tick seasons, allowing them to progress further north.3 The projections are based on high greenhouse gas emission scenarios, and the greenhouse gases are very much—
Wait. Why am I defending the methodology? Shouldn't you be asking why we're still calling them "projections" when Long Island just recorded its highest tick population on record in 2025?4 Isn't the real question why I'm still drawing maps of 2050 when 2050 keeps showing up early?
She picks up another map, puts it down. Picks it up again.
So why are you still drawing maps of 2050?
Because public health planning requires—
Does it? Does planning require futures that hold still long enough to plan for? My 2019 projections had Lyme reaching these regions by 2045. My 2022 revisions moved it to 2040. Now we're seeing suitable habitat areas appearing in 2025. So what is planning, exactly? The act of drawing lines on maps? The pretense that we can see what's coming?
Have you ever tried to map something that won't stop moving? Have you ever tried to draw a border around something that's already crossed it?
That sounds—
Impossible? But is difficult the right word? Difficult implies a problem with a solution. What do you call the act of projecting disease burden when the projection keeps arriving early? What do you call it when your model says five billion people could be exposed to dengue by 2050, but 12.4 million cases were already reported in 2024?5
Is that forecasting? Prediction? Or just describing something that's already happening while pretending it's still in the future?
What would you call it?
I don't know. What would you call it?
She laughs. It's not a comfortable sound.
I wouldn't. Can I? Can I call it anything when the categories keep dissolving?
We have indicators. Surveillance of specific species of concern. Emerging human and wildlife diseases. Suitable habitat areas. Meteorological factors. Sentinel animals.6 But what good are indicators when they're indicating something that's already indicated itself? When the sentinel animals are already sick? When the suitable habitat has already arrived?
Don't you think there should be a word for that? Shouldn't someone have invented a word for the thing we're doing?
Maybe there isn't a word because we've never had to do this before.
Never had to—but that's the problem. That's exactly the problem. We're using projection tools designed for gradual change to map something that's—
How do you map acceleration? How do you draw a line between 2025 and 2050 when 2050 keeps showing up early? When your high-emission scenario becomes your moderate-emission scenario becomes your low-emission scenario, all in three years?
Do you revise the map? Do you revise the timeline? Or do you just keep drawing lines and hope someone—
Who? Who's supposed to use these maps? Who's supposed to plan for something that's already here?
Public health officials? Policymakers?
Right. Policymakers. The ones who committed $300 billion annually by 2035 for climate adaptation, when the adaptation finance gap is already $187 to $359 billion per year. Achieving that goal would reduce the gap by 5 percent.7 Five percent.
Those policymakers? The ones making plans for 2035?
But what year is it now? What year is it when I'm drawing maps? Because if it's 2025, and I'm projecting 2050, but 2050 keeps arriving in 2025, then what year am I actually in? What year is anyone in?
Can you tell me? Can anyone tell me what year we're living in anymore?
It's 2025.
Is it? Are you sure?
Because the temperature data says 2024 was 1.55 degrees Celsius above pre-industrial levels. When was that supposed to happen? When did we think we'd hit 1.5 degrees? Wasn't it supposed to be later? Wasn't everything supposed to be later?
But if later keeps becoming now, and now keeps becoming then, then when am I? When are any of us?
She's holding a map now, staring at it like it might answer.
And if I don't know when I am, how can I possibly tell you where Lyme disease will be?
I think that might be the point. That you can't.
Can't, or shouldn't?
She stops. Puts the map down carefully.
Those are different things. Can't implies impossibility. Shouldn't implies—what? Choice? Ethics? The recognition that some acts are fundamentally absurd?
But if it's absurd, why am I still here? Why am I still drawing these maps with their colored zones and their confident projections and their neat little legends explaining what each color means?
Why does anyone still draw maps of the future when the future won't—
Won't what?
Won't hold still. Won't wait. Won't be mapped. Won't be projected. Won't be anything except what it already is, which is here, which is now, which is—
What am I even doing? What is anyone doing? Drawing lines on maps while the lines redraw themselves? Making thirty-year forecasts while the thirty years collapse into three? Telling people where diseases will be in 2050 while diseases laugh at the very concept of 2050?
Is that science? Is that planning?
Or is it just pretending to see the future when the future is already the past?
What do you call that?
I don't know.
Neither do I. Neither does anyone. But we keep doing it anyway.
We keep drawing the maps. We keep making the projections. We keep writing the reports that say "by 2050" and "under high-emission scenarios" and "if current trends continue," as if trends were something that continued rather than something that accelerated past recognition. As if 2050 were a place we might still arrive at instead of a place we've already passed. As if maps could contain something that's already escaped.
Don't you think that's strange? Don't you think someone should mention that? That we're all just—that I'm just—
Just what?
She looks at me for the first time in several minutes.
I don't know.
Do you? Does anyone? Can anyone tell me? Can anyone tell me what I'm supposed to be doing if not this? If not drawing maps that lie by telling the truth too slowly? If not making projections that arrive before they're projected?
If not this, then what else is there? What else can there possibly be?
Can you tell me?
Please?
Can someone please tell me what else there is?
The map in her hands has dates crossed out in red marker. 2045. 2040. 2035. She picks up the marker again, hesitates over 2030, then puts it down without crossing anything out.
"Same time next week?" she asks.
I don't know how to answer that question.