I used to think optimists were naive and pessimists were smart. Pessimism seemed like an essential feature of being a scientist: the basis of science is to challenge every result, to pick theories apart to see which ones stand up. I thought cynicism was one of its founding principles. Maybe there is some truth to that. But science is inherently optimistic too. How else would we describe the willingness to try experiments over and over, often with slim odds of success?

Scientific progress can be frustratingly slow: the best minds can dedicate their entire lives to a single question and come away with nothing. They do so with the hope that a breakthrough might be round the corner. It’s unlikely they will be the person to discover it, but there’s a chance. Those odds drop to zero if they give up.

Nevertheless, pessimism still sounds intelligent and optimism dumb. I often feel embarrassed to admit that I’m an optimist. I imagine it knocks me down a peg or two in people’s estimations. But the world desperately needs more optimism. The problem is that people mistake optimism for “blind optimism,” the unfounded faith that things will just get better. Blind optimism really is dumb. And dangerous. If we sit back and do nothing, things will not turn out fine. That’s not the kind of optimism that I’m talking about.

Optimism is seeing challenges as opportunities to make progress; it’s having the confidence that there are things we can do to make a difference. We can shape the future, and we can build a great one if we want to. The economist Paul Romer makes this distinction nicely. He separates “complacent optimism” from “conditional optimism.” “Complacent optimism is the feeling of a child waiting for presents,” Romer wrote. “Conditional optimism is the feeling of a child who is thinking about building a treehouse. ‘If I get some wood and nails and persuade some other kids to help do the work, we can end up with something really cool.’”

I’ve heard various other terms for this “conditional” or effective optimism: “urgent optimism,” “pragmatic optimism,” “realistic optimism,” “impatient optimism.” All these terms are grounded in inspiration and action.

Read More: 13 Ways the World Got Better in 2023

The reason pessimists often sound smart is that they can avoid being “wrong” by moving the goalposts. When a doomer predicts that the world will end in five years, and it doesn’t, they just move the date. The American biologist Paul R. Ehrlich—author of the 1968 book The Population Bomb—has been doing this for decades. In 1970 he said that “sometime in the next 15 years, the end will come. And by ‘the end” I mean an utter breakdown of the capacity of the planet to support humanity.” Of course, that was woefully wrong. He had another go: he said that “England will not exist in the year 2000.” Wrong again. Ehrlich will keep pushing this deadline back. A pessimistic stance is a safe one.

Don’t mistake criticism for pessimism. Criticism is essential for an effective optimist. We need to work through ideas to find the most promising ones. Most innovators that have changed the world have been optimists, even if they didn’t identify as one. But they were also fiercely critical: no one picks apart the ideas of Thomas Edison, Alexander Fleming, Marie Curie, or Norman Borlaug more than they did themselves.

In particular, if we want to get serious about tackling the world’s environmental problems, we need to be more optimistic. We need to believe that it is possible to tackle them. And if we do, we can be the first generation to achieve a sustainable world.

More From TIME

The Last Generation is an activist group in Germany, the name implying that our unsustainability will push us to extinction. To force their government into action, some of the group went on a month-long hunger strike in August 2021. It wasn’t a half-hearted effort: several ended up in hospital. They’re not the only ones who feel this way. The global environmental group Extinction Rebellion is also founded on this principle. And the studies show that the notion of us being the ‘last generation’ isn’t far from the minds of many young people.

But I’d like to take the opposite framing. I don’t think we’re going to be the last generation. The evidence points to the opposite. I think we could be the first generation. We have the opportunity to be the first generation that leaves the environment in a better state than we found it. The first generation in human history to achieve sustainability.

Read more: We Need Climate Action Everywhere, All at Once

Yes, that seems hard to believe. I’ll explain why. Here I’m using the term “generation” loosely. I am from a generation that will be defined by our environmental problems. I was a child when climate change really came on the radar. Most of my adulthood will be spent in the midst of the major energy transition. I will see countries move from being almost entirely dependent on fossil fuels to being free of them. I will be 57 when governments hit the “2050 deadline” of reaching net-zero carbon emissions that so many have promised.

But, of course, there will be several generations involved in this project. There are a couple above me—my parents and grandparents—and a couple below me, my future children (and perhaps grandchildren). Generations are often pitted against each other: older generations are blamed for ruining the planet; younger generations are framed as hysterical and indignant. When it comes down to it, though, most of us want to build a better world, where our children and grandchildren can thrive. And we all need to work together to achieve that. All of us will be involved in this transformation.

Urgent optimism isn’t about looking away from the climate crisis that faces us. It’s about facing up to it, not from a place of ‘damage limitation’ but with a clear vision of the future we can build. One that not only stops warming in its tracks but builds a better world for us – all of us – and the species that we share the planet with.

That’s not going to happen on its own. It’s something we need to fight for.

Excerpted from NOT THE END OF THE WORLD by Hannah Ritchie. Copyright © 2024 by Hannah Ritchie. Used with permission by Little, Brown Spark, an imprint of Little, Brown and Company. All Rights Reserved.

ncG1vNJzZmismaKyb6%2FOpmZvbWVngHOFjq6poJ2eqXqwvNOipKKrnWKwrbXMmqueZZGYwaq7zWacrKuRrnw%3D