Dear Uncle,

I guess you sent me this article because you see how worried I am about climate change on twitter and you don’t believe it’s happening. I remember you talking about the emails hacked from the Climate Research Unit at UEA several years ago, but I didn’t realize you were skeptical about the effects of climate change.

I am very sorry to say that climate change is happening. I don’t want to believe it’s true and I don’t want to believe it’s as bad as it is. My whole PhD is premised on the idea that maybe [a really important species] would be able to adapt better than our projections said because of [cool feature of their biology]. (I don’t have the answer yet, but it’s not looking promising.)

I’ve spent the last 15 years learning about biology and ecology and the natural world and participating in the scientific process and working with other scientists. Obviously, I don’t know everything and science isn’t perfect. But most of us are trying our best and aren’t out to trick anyone. I believe climate change is happening and so does nearly every scientist I’ve ever known. We have disagreements about how fast it’s happening and what its exact effects will be and if we can survive it, but we agree that it’s going to be very, very bad.

I’m so convinced climate change is happening that I spend a great deal of time that I should be working on my PhD or that I could be doing things I love like reading novels and dancing instead writing letters to politicians and advocating for policies that would help slow climate change or at least help us adapt. I’m so convinced that I cry about it and am terrified about the world I’ll grow old in. I’m so convinced that I’ve tried to convince my mother to move (and I think you all probably should as well, especially your kids) because the southeast is going to get so much hotter and flood and fire prone during my lifetime that it’s going to severely disrupt the economy and make people very sick.

And I’m not alone. The news doesn’t spend a lot of time talking to scientists about how they feel personally about climate change, but it’s bleak. We give dry presentations and cry together over dinner at how many plants died at our study sites. We talk about fears for our children or choosing not to have them. I’m afraid of what the world is going to be like in 20 years and I’m grieving the ecosystems dying right in front of us.

The article you sent me says that the recent National Climate Assessment is based on cherry picked data and bad models and bad science and that fossil fuels have done a lot of good. It claims that all this noise about climate change is just a ploy to control politics. It isn’t, though an emergency of this scale really should affect politics.

The climate models were right before the internal combustion engine was invented

I know it can seem like everything about climate change is based on these overly complex computer models run by scientists who only care about getting their next grant, but those computer models are just fiddly details.

We knew that using fossil fuels and such could cause global warming from before the US Civil War – more than 150 years before we were able to build the complex global models of climate that we’re now using to figure out exactly how global warming will change regional and local climates.

The earliest calculations of how much carbon dioxide warmed up the planet were done by a Swedish scientist in the 1890s. His predictions weren’t perfect, but they’re not that far off from our current models. And the simple computer models we built in the 70s and 80s predict basically the same global temperature increase as the highly complex ones we have today.

(We keep building more and more complex models with more and more things because we are trying to understand more and more local effects and also feedback cycles – what does it mean for the world to warm 2 or 6 or 10 degrees? When will the ice melt? How will that affect ocean currents? How will the ocean currents full of meltwater affect the speed and sinuousness of the jetstream? Will the southwest get wetter or drier? Will there be more hurricanes or fewer? What could the economic impacts be?)

Perhaps that snippet of scientific history hasn’t convinced you to take climate change seriously. After all, even if we know that carbon dioxide and other greenhouse gases heat up the planet, maybe we’ve done our math wrong and it’s actually much slower than we think.

But what if the models are wrong and climate change isn’t a big deal?

So, what if the models are wrong about how much and how fast climate change is happening? We need to compare the risk of inaction vs action if we’re right and if we’re wrong.

What is the risk of inaction if we are right about the magnitude and speed of climate change impacts? Well, you could read the fourth NCA to find out! It does not, as the article you sent me put it “sound like something kicked around in a Hollywood brainstorming session for a science fiction thriller.” It is sober and measured and accessible – and ultimately very conservative in its discussion of potential impacts. Here’s a representative snippet from the chapter on climate change impacts occurring and expected in the Southeast

Embedded in these land- and seascapes is a rich cultural history developed over generations by the many communities that call this region home. However, these beaches and bayous, fields and forests, and cities and small towns are all at risk from a changing climate. These risks vary in type and magnitude from place to place, and while some climate change impacts, such as sea level rise and extreme downpours, are being acutely felt now, others, like increasing exposure to dangerously high temperatures—often accompanied by high humidity—and new local diseases, are expected to become more significant in the coming decades.

If our models are right and we don’t do anything, the impacts from climate change will be big and bad this century and downright apocalyptic in the next. The only reason not to act would be if you believe the impacts of trying to slow or stop climate change are worse than the risks from climate change itself.

The biggest things we can to do as a society to slow climate change are:

• educate girls and make sure women have access to contraceptives and reproductive healthcare, including abortion
• change the kind of chemicals we use as refrigerants (like in air conditioners) (and switch as many of them as we can to things like ground source heat pumps).
• switch electricity generation from coal and natural gas to solar and wind as fast as we can, reducing air pollution in the process and creating a bunch of jobs
• Eat more beans and less red meat while wasting less food – cheaper and healthier!
• Stop burning tropical forests – most are being burnt to grow soybeans to feed cows, so this is almost a natural outcome of the previous goal
• Bring back silvopasture farming techniques – supporting small farmers and rural areas and loosening the exploitation by companies like Smithfield.

None of these have costs higher than the ones our models predict climate change will exact, in dollars, in lives, in social and cultural disruption. Most are actually things we’d want to do regardless of climate change. Many negative effects are things that are happening anyway.

Consider what happens

If we don’t act and the models are right, we face a serious existential threat. Over the next centuries, billions of people will die in extreme weather events, wars, and famines, the economy will collapse worldwide, we could lose a great deal of technology and civilization, and could even go extinct. Large parts of the tropics and subtropics will become uninhabitable and billions will be forced to migrate by rising sea levels and increasing temperatures. Immigration by climate refugees will completely overwhelm many countries. Many, many species will go extinct.

If we don’t act and the models are wrong, we gradually decarbonize the economy anyway while demographic, habitat destruction, and agricultural problems continue unabated. The transition to solar and wind will continue, relatively slowly, because technology has advanced already to the point that it’s cheaper than at least coal already. As fossil fuels are gradually depleted and renewable tech continues to improve, the transition will speed up. This will gradually reduce the millions of deaths every year due to air pollution. Depending on the speed of transition, we will have to retrain or support people and communities who used to be dependent on fossil fuel extraction – or consign them to lives of poverty and us all to political unrest. Hundreds of millions more women will have children they weren’t ready to have and lack education and opportunities, holding back their countries’ political and economic development. Industrial agriculture will continue to destroy habitat and small farms and suck resources out of rural areas. The loss of rainforests will cause the loss of many incredible species and result in changes to global weather patterns that could devastate some agricultural regions. Obesity and metabolic diseases will continue to increase, along with associated healthcare costs.

If we act and the models are right, we’re still going to continue to see a lot of climate change impacts because we’ve just waited too long to act, but the effects won’t be so catastrophic. Fewer people will die in extreme weather events or of starvation, and immigration will be less overwhelming because fewer people will have to flee sea level rise and increasingly inhospitable climates. We will save millions of lives every year just from the reduction in air pollution from transitioning to solar and wind. Many jobs will be created in order to rapidly transition to solar and wind and improve energy efficiency in buildings. We will have to retrain or support people and communities who used to be dependent on fossil fuel extraction – or consign them to lives of poverty and us all to political unrest. More people will use affordable heat pumps or safe refrigerants to cool (and heat) their homes than before. Dietary improvements in the west will extend lives and reduce healthcare costs from metabolic disease. Population growth will slow, helping countries in the global south reduce emigration and stabilize their political systems. We will lose rare desert habitat to solar farms and some birds to wind farms, but much less than unmitigated climate change would have caused. Switching so rapidly to renewable energy with today’s technology will mean a lot of mining for rare earth minerals, which will likely cause large areas of environmental destruction in parts of the American west and China – much as uranium mining and coal mining did in the previous century.

If we act and the models are wrong, we will make improvements in agriculture, public health, political stability in tropical and subtropical countries, gender equality, and environmental protection, at the expense of some resource extraction communities. We will deal with the necessary transition away from fossil fuels earlier than we needed to to avoid climate change impacts, possibly with technologies that aren’t as advanced as they would have been had we waited. However, we will save millions of lives every year just from the reduction in air pollution from transitioning to solar and wind. Many jobs will be created in order to rapidly transition to solar and wind and improve energy efficiency in buildings. We will have to retrain or support people and communities who used to be dependent on fossil fuel extraction – or consign them to lives of poverty and us all to political unrest. More people will use affordable heat pumps or safe refrigerants to cool (and heat) their homes than before. Dietary improvements in the west will extend lives and reduce healthcare costs from metabolic disease. Population growth will slow, helping countries in the global south reduce emigration and stabilize their political systems. We will lose rare desert habitat to solar farms and lots of birds to wind farms. Switching so rapidly to renewable energy probably will mean a lot of mining for rare earth minerals, which will cause environmental destruction in parts of the American west and China – much as uranium mining and coal mining did in the previous century. Many species are saved in the rainforests.

You believe that the models are wrong and we we shouldn’t act. You’re afraid that the models are wrong and we will act.

But your fear is actually the very best outcome: the very best situation is if we act to stop climate change and we are wrong about climate change. Acting to stop climate change makes the world better even if climate change doesn’t happen.

(The above assumes, of course, that the models are overpredicting climate change impacts. We are very likely under-predicting the impacts of climate change. Choosing what to do, what to prioritize, if climate change is going to be much worse than we imagine is another discussion.)

I don’t think any of these futures are easy, even the ones where everyone does exactly what I think is politically right and things go perfectly according to plan. We have waited so long to act to stop climate change that we now have to act very fast and no matter what we’ll do, bad things will happen. Fast change is very hard and disruptive. We’re going to face fast change no matter what, but we have a choice, now about what that change looks like. We can choose the change and we can get our collective butts in gear, or we’ll be swept away by changes we didn’t see coming, alone.

What if there were no models?

But perhaps you believe any model of climate change is just wrong. (They are, of course. The only perfect model is the thing itself, but you’re not going to throw out all your maps because they don’t have every pothole in the road on them.)

So then – imagine that we don’t have any of these climate models.

We still know that some gases like carbon dioxide and methane hold more heat than others because anyone can figure that out with some sunshine and bottles filled with different gases on a sunny day and a couple thermometers.

But if no one ever built the kinds of models predicting what adding lots and lots of greenhouse gases to the atmosphere would do, then what should we do if we just don’t know what the result of dumping greenhouse gases in the atmosphere will be?

I believe we must act very cautiously. We only have one planet. It is foolish and selfish to take more than the smallest of risks with it.

If we don’t know how much greenhouse gases will warm up our planet or what warming up a planet will do to climate, we just shouldn’t do it until we do understand. Experimenting with the only planet we can currently survive on does not seem sensible.

In our climate-model-less world, we also still know that climate is a complex dynamical system, like the human brain or the power grid, where small changes in one part of the system can cause rather larger changes in another. Bigger changes are quite likely to cause bigger changes. In a world without global climate models, we would want to be very wary of changing levels of temperature-changing gases in our atmosphere much at all.

If we know that greenhouse gases can cause global warming and we know that the global climate system can behave unpredictably, then even if we don’t know how or why or how much change those gases cause, it is irresponsible and dangerous to continue increasing greenhouse gas concentrations.

I want us to fix climate change, but I don’t want you to feel like this

Academics get accused of elitism all the time. And some of that is completely warranted. This next bit is elitist.

I want everyone to take climate change seriously because we have waited so long and so must do so much, so fast to stave off the most unthinkable effects. But part of me doesn’t want to convince you, my dear uncle.

Changing your mind, individually, probably won’t make much difference to whether we get a Green New Deal or not.

But understanding what climate change impacts will look like is horrifying and painful. You’re old enough and well-off enough that you and Aunt ____ will probably be fine as long as your AC keeps going and you don’t move to the coast. I don’t want you to spend the rest of your life terrified for my cousins and your new grandbaby, mourning the changes to the land you love as trees and animals migrate and change and die.

So I’m not going to send you this letter, I’m not going to try to convince you that climate change is real. Facing it is like facing death, and of course I would spare you that if I could.

So live your life, blissfully ignorant and cheerful on the phone about the strange weather lately. Live free from the fear that everything you’ve contributed to and cared about in your life will be gone so soon and live free from the guilt that you supported the political and economic choices that may kill us all.