Why scientists say veganism is key to fighting climate change

I spent fifteen years in finance, analyzing risk and running numbers. I learned to trust data, to follow where the evidence leads, even when the conclusions felt uncomfortable.

So when I started reading the research on food systems and climate change, I couldn't look away. The science was clear, and it was asking something of me.

What struck me wasn't just the scale of the problem. It was the directness of the solution. We talk about electric cars and solar panels and policy changes, and those matter enormously.

But the research keeps circling back to something far more personal: what we choose to eat, three times a day, every single day.

The weight of what we eat

In 2018, researchers at the University of Oxford published what became one of the most comprehensive analyses of food's environmental impact ever conducted.

The study, which examined data from nearly 40,000 farms across 119 countries, found that animal agriculture uses 83% of farmland while providing only 18% of global calories. That disparity stopped me in my tracks.

Think about that for a moment. We're dedicating the vast majority of our agricultural land to produce a fraction of our food. The inefficiency is staggering, and it comes with a cost measured in greenhouse gases, deforestation, and water use. Lead researcher Joseph Poore put it plainly: avoiding meat and dairy is the single biggest way to reduce your environmental impact on Earth.

Beyond carbon: the full picture

Climate conversations often focus on carbon dioxide, but the food system tells a more complex story.

Cattle and other ruminants produce methane, a greenhouse gas roughly 80 times more potent than CO2 over a 20-year period. Manure management releases nitrous oxide. Feed crop production requires fertilizers that emit their own gases.

When scientists at the United Nations Environment Programme examined global food systems, they found that animal agriculture is a leading driver of biodiversity loss, land degradation, and water pollution.

The Amazon rainforest, often called the lungs of our planet, continues to be cleared primarily for cattle ranching and soy production to feed livestock.

Have you ever considered how many ecosystems are reshaped simply to grow food for animals that become food for us?

The land we could reclaim

Here's where the data becomes hopeful. A global shift toward plant-based eating wouldn't just reduce emissions. It would free up land on a scale that's hard to imagine. That Oxford study estimated that if everyone went vegan, global farmland use could be reduced by 75%.

That reclaimed land could return to forest, grassland, and wetland, ecosystems that actively pull carbon from the atmosphere. It's called carbon sequestration, and it represents one of our most promising tools for addressing the climate crisis. The land is already there. We're just using it inefficiently.

I think about this when I'm trail running through the forests near my home. These woods exist because someone, at some point, decided not to clear them. What if we made that choice on a global scale?

Individual action in a systemic crisis

I understand the skepticism around individual choices. I've felt it myself. When you're watching corporations emit billions of tons of greenhouse gases, does your breakfast really matter? The research suggests it does, and not just symbolically.

A 2023 study published in Nature Food found that high-meat diets produce roughly twice the greenhouse gas emissions of vegan diets.

Multiply that by millions of people making daily food choices, and the numbers become significant. Consumer demand shapes markets. Markets shape production. Production shapes land use and emissions.

This doesn't mean individual action replaces systemic change. It means they work together. Policy follows culture, and culture shifts one meal at a time.

The practical path forward

When I went vegan at 35, I didn't do it perfectly. I made mistakes, missed nutrients, and occasionally felt overwhelmed.

But I also discovered something unexpected: the transition was easier than I'd feared. Plant-based eating has become more accessible, more delicious, and more nutritionally understood than ever before.

What helped me was approaching it analytically, the same way I'd approach any significant decision. I read the research. I planned my meals. I gave myself grace when I stumbled. The goal wasn't purity. It was progress.

What would it look like for you to take one step in this direction? Maybe it's a meatless Monday. Maybe it's swapping dairy milk for oat. Small changes, made consistently, add up to something larger than any single choice.

Final thoughts

The science on veganism and climate change isn't ambiguous. It's pointing us toward a clear, actionable response to one of the defining challenges of our time. That doesn't make the transition simple, but it does make it meaningful.

I left finance because I wanted my daily actions to align with my values. Choosing what I eat turned out to be one of the most direct ways to live that alignment. The planet is asking something of us. The question is whether we're willing to listen.