How global warming will change your diet

Superfood: Wheat, maize and rice provide 60% of calories obtained by humans from plants.

Studies suggest that our most vital crops are in danger of extinction, and climate change is partly to blame. The answer could lie in eating different types of food — including insects.

  • What is the problem?

    According to scientists, there have been six “mass extinctions” of wildlife on Earth. Most were caused by natural disasters, including huge volcanic eruptions and ice ages. One mass extinction happened 65 million years ago when a giant asteroid wiped out the dinosaurs.

    The sixth and most recent one is happening right now. And it is all our fault. Destruction of habitats, over-hunting, pollution and climate change have killed half of all animals on Earth in the last 40 years.

  • But what has this got to do with food?

    This extinction event also affects plants and livestock. Last year, a report stated that the world food supply is “failing”. Ann Tutwiler, who led the study, said that “huge proportions” of plants and animals grown for food are endangered.

  • What foods could disappear?

    Up to 20% of all plant species are facing extinction. That includes some of our favourite foods. Around 20% of wild potatoes could be extinct by 2055, and wild coffee could disappear by 2080. Ghana and Ivory Coast produce 70% of the world’s cocoa, which is used to make chocolate. But if global temperatures rise by 2C, it will be too hot for these cocoa trees to grow.

  • But humanity will survive without chips, coffee, and chocolate?

    Maybe so, but that is not all. Farming methods employed over the last 100 years have made the whole system extremely vulnerable. Between 1900 and 1999, 75% of crops became extinct. In 1903 there were 307 varieties of sweetcorn seed available in the US. By 1983, there were only 12 known varieties. This happened because, as demand for food grew, farmers stopped planting many varieties of seed, only planting those with the highest yields. High yields are good in the short term, but plants with fewer seed varieties could become diseased and die out.

  • What would happen then?

    If key crops are destroyed, it would be disastrous. One study showed that every decade there is a 6% chance that maize crops will simultaneously fail in the US and China. This would lead to a “global” famine.

    There have been warning signs. In the 1970s, the US maize crop was devastated by a blight epidemic which destroyed around 50% of yields, worth a billion dollars. The epidemic was ended by using blight-resistant genes from a Mexican variety of the crop. If seed diversity continues to decline, this solution may not be possible in the future.

  • What could we do to stop it?

    If things got that bad, there is a backup plan. Buried deep into the ice of the Norwegian island of Svalbard is the Global Seed Vault. Inside, researchers are attempting to collect a specimen of every existing seed on the planet. This will stop more plants dying out, and provide a seed bank to avert worldwide famine. According to Cary Fowler, director of the Global Crop Diversity Trust, the vault “will literally save millions of lives”.

    In the meantime farmers must grow a wider range of crops. Humans currently farm a very small range of foods. There are between 250,000 and 300,000 edible plants in the world. But humans only grow between 150 and 200 of them.

  • So we could start seeing new foods in the future?

    Quite probably. According to Kathy Willis, professor of Biodiversity at Oxford University, 2,000 new plant species are discovered every year, with “five new species of onion” discovered in 2015.

    It would also help if we all started eating insects. By replacing half of our meat consumption with crickets we could cut farmland by a third, and dramatically reduce the effects of climate change. Crickets are also very high in protein.

You Decide

  1. Would you start eating insects to help the environment?

Activities

  1. Consider the top five plants in the global food supply: sugar cane, maize, rice, wheat and potatoes. Write down as many different food products as you can which these plants help to produce.

Subjects

Word Watch

Scientists
The study was led by Gerardo Ceballos of the Universidad Nacional Autónoma de México.
Report
Released by Biodiversity International.
20%
According to the State of the World’s Plants report, conducted by researchers at Royal Botanic Gardens Kew. The report was edited by Professor Willis, on secondment from Oxford University, mentioned in the final answer (A) above.
Ghana and Ivory Coast
Countries located on the west coast of Africa.
One study
The study was led by Chris Kent of the UK Met Office.
Blight
A common plant disease, typically caused by fungi.
75%
According to 1999 study conducted by the United Nations Food and Agriculture Organisation.
Svalbard
The island is one of the northernmost settlements on the planet. It lies halfway between mainland Norway and the North Pole.