What would happen if the whole world became vegetarian?

January 10, 2026 •

4 min read

Food production is responsible for over a quarter of all global greenhouse gas emissions, with animal agriculture being a major contributor. So, what would happen if the whole world became vegetarian? The answer involves a complex mosaic of profound environmental improvements, massive economic shifts, and deep societal challenges.

Quick Summary

This analysis delves into the intricate and multi-faceted impacts of a global dietary shift to vegetarianism. The article explores the environmental benefits, economic disruptions, and public health outcomes of such a widespread dietary change.

Key Points

Environmental Rebound: A worldwide shift would drastically reduce greenhouse gas emissions from agriculture, particularly methane from livestock.
Land Repurposing: Vast tracts of land previously used for animal grazing and feed crops would be freed up for reforestation, biodiversity restoration, or crop production.
Economic Disruption: The global livestock, meatpacking, and fisheries industries would collapse, causing significant job losses that would require extensive retraining for millions of workers.
Healthier Populations: Rates of chronic diseases like heart disease and type 2 diabetes could fall dramatically due to a lower intake of saturated fat and higher fiber consumption.
Nutrient Vigilance: Global health authorities would need to focus on preventing deficiencies in vital nutrients like Vitamin B12, iron, and zinc, which are more readily available in animal products.
Food Security: A more efficient plant-based food system could potentially feed the growing global population using fewer resources and less land.
Cultural Shift: Food-related cultural norms, traditions, and social gatherings would undergo significant and challenging transformations globally.

Environmental Transformation

If the world transitioned to a vegetarian diet, the most immediate and dramatic changes would be seen in the environment. Animal agriculture is a significant contributor to climate change, deforestation, and water pollution. Removing this burden would trigger a cascade of positive ecological effects.

Reduced Greenhouse Gas Emissions

Livestock farming contributes significantly to greenhouse gas emissions, primarily through methane from cattle and nitrous oxide from manure. A global shift away from meat and dairy could drastically cut these emissions. Studies have shown that a vegan diet can cut diet-related greenhouse gas emissions by up to 71%. The methane reduction alone would have a powerful, near-term effect on mitigating climate change.

Massive Land Reallocation

Animal agriculture utilizes a staggering 83% of the world's farmland, despite providing only a fraction of its calories and protein. A global vegetarian shift would free up vast tracts of land—an area roughly the size of Africa. This newly available land could be repurposed for several critical uses:

Reforestation and rewilding: Large areas could be allowed to revert to native grasslands and forests, creating carbon sinks and revitalizing biodiversity.
Crop cultivation: Some former pastureland could be used to grow crops for human consumption, efficiently producing more food with less land.
Habitat restoration: Restoring natural habitats would benefit wildlife, potentially reversing biodiversity loss driven by agricultural expansion.

Water Conservation and Ecosystem Health

Meat production is extremely water-intensive. Producing a kilogram of beef requires thousands of liters of water, far more than crops like cereals or vegetables. A global vegetarian diet would significantly reduce agricultural water consumption, freeing up freshwater resources. Additionally, it would dramatically decrease water pollution from animal waste runoff, helping to combat eutrophication in lakes and rivers.

Economic and Societal Upheaval

The global economic and social impacts of a rapid transition to vegetarianism would be complex and challenging. While new opportunities would arise, existing industries would face significant disruption.

Disruption of the Livestock Industry

The most immediate challenge would be the dismantling of the global livestock and fisheries industries. Over a billion people are employed in livestock-related fields, particularly in developing nations. The sudden obsolescence of these livelihoods would necessitate massive retraining and social safety net programs to assist affected workers, from small-scale farmers to meatpackers.

Emergence of New Economic Sectors

At the same time, the transition would fuel the growth of new industries. The plant-based food sector, already expanding rapidly, would boom with increased demand. Investments would pour into plant-based meat and dairy alternatives, novel protein research, and sustainable plant agriculture. This could lead to net job creation in new, green sectors, offsetting some of the losses from animal agriculture.

Comparison: Pre-Vegetarian World vs. Global Vegetarianism


Aspect	Pre-Vegetarian World (High Meat Consumption)	Global Vegetarianism
Greenhouse Gas Emissions	High, with significant methane and nitrous oxide contributions from animal agriculture.	Drastically reduced, helping to mitigate climate change.
Land Use	Inefficient, using 83% of agricultural land for animals that provide limited calories.	Highly efficient, freeing up immense land for reforestation and diverse crops.
Water Footprint	Enormous, particularly for beef production, contributing to water scarcity.	Significantly reduced, conserving freshwater resources.
Biodiversity	Severe biodiversity loss due to deforestation for grazing and feed crops.	Potential for significant biodiversity recovery through habitat restoration.
Global Health	Higher risk of chronic diseases like heart disease, diabetes, and certain cancers.	Lower rates of chronic diseases, but potential for nutrient deficiencies if not managed.
Economic Structure	Reliant on established animal agriculture industry, impacting millions of jobs.	Transformative, with major disruption to existing jobs and growth in plant-based industries.

Global Health and Nutritional Considerations

Adopting a plant-based diet globally would have profound and mixed implications for human health. On one hand, it offers significant improvements in combating chronic diseases, but on the other, it introduces risks of nutritional deficiencies if not properly managed.

Decreased Chronic Disease Risk

Well-planned vegetarian diets are often associated with a reduced risk of obesity, type 2 diabetes, heart disease, and some forms of cancer. This is largely due to the higher intake of fiber, vitamins, and phytochemicals, and lower consumption of saturated fat and cholesterol. Globally, this could lead to millions of avoided premature deaths annually.

Risk of Nutrient Deficiencies

A global population shift would require widespread education to prevent nutritional deficiencies. Key nutrients naturally more abundant in animal products, such as Vitamin B12, iron, zinc, calcium, and Omega-3 fatty acids, would need careful management. Fortified foods and strategic dietary planning would be essential to ensure global health security, particularly for vulnerable populations in resource-poor regions.

A Complex Future

Ultimately, a world that became vegetarian wouldn't be a simple utopia or a dystopian nightmare. It would be a messy, complex, and transformative process with long-term ecological benefits and major short-term disruptions. Success would depend entirely on how thoughtfully humanity managed the transition, prioritizing equitable economic restructuring and widespread nutritional education. The world has a proven capacity to adapt to large-scale economic and social shifts, and a dietary transformation would be the ultimate test of that capacity. The question is not just what would happen, but how we would collectively choose to manage it. The benefits to the planet would be immense, but the human cost of transition would require careful, cooperative, and compassionate global management.

More evidence can be found in a detailed report by the World Health Organization on plant-based diets and health.

Frequently Asked Questions

Yes. Producing plant-based foods is significantly more efficient than producing meat, freeing up vast amounts of land and resources. One study found that transitioning away from animal-based diets could increase the world food supply by 49% without increasing cropland.

There would be no incentive to continue breeding farm animals. Their populations would likely shrink dramatically, with some species being maintained in sanctuaries. There is no simple, single answer to how the transition would be managed humanely.

While well-planned vegetarian diets are healthy, a sudden global shift without proper education could lead to deficiencies in Vitamin B12, iron, and zinc. This would require widespread nutritional education and the development of more fortified plant-based foods.

The economic impact would be severe for those in the livestock industry, leading to massive job losses. However, a shift could also spur significant job growth in the plant-based food industry and related sectors, creating new economic opportunities.

The environmental benefits would be profound. It would lead to significant reductions in greenhouse gas emissions, vast areas of land being rewilded, decreased water usage, and less pollution from agricultural runoff.

No. The impacts would vary greatly depending on a country's economic reliance on animal agriculture and its existing dietary norms. Developing countries heavily reliant on livestock for livelihoods would face more severe disruptions.

Besides the economic and social upheaval of the transition, there are potential risks, such as nutrient deficiencies for those with less dietary awareness. Some fear an increased demand for fertilizers if manure is no longer widely available, but this is a solvable management issue.