Watermelon, green beans and bell peppers are among the many common fruits and vegetables found in US supermarkets that contain potentially unsafe levels of pesticides, according to an analysis published today by Consumer Reports.

The new report – which analyzed seven years of US Department of Agriculture data on commonly eaten fruits and vegetables – offers one of the most comprehensive evaluations to date of pesticides found in US produce. The data was based on nearly 30,000 fruit and vegetable samples, including fresh, frozen, canned and organic, collected from supermarkets by the USDA as part of routine pesticide testing.

Consumer Reports built a huge database to analyze the data – and scored different foods to provide actionable recommendations to help consumers shop and eat with less risk.

Consumer Reports found that pesticide residue posed a significant risk in roughly 20% of the 59 common foods examined in its research. The foods deemed high risk included conventionally grown (ie non-organic) kale, blueberries, potatoes and bell peppers. Apples, grapes, peaches, tomatoes, spinach and celery were among the items considered moderate risk.

Organic fruits and vegetables generally had far less pesticide residue than conventionally grown foods, according to the research. But even a few organic foods posed some risk. For example, imported green beans carried a high risk and domestic potatoes a moderate one – raising questions about how these organic crops were contaminated with high-risk pesticides that are not approved for organic farming.

Imported, conventionally grown produce also posed higher risks than US-grown foods in the study. Foods grown in Mexico such as strawberries and green beans were especially worrisome. Mexican strawberries contained oxydemeton-methyl, part of a group of pesticides called organophosphates that are neurotoxins. This category of insecticides can overstimulate the nervous system at high exposure levels and disrupt the developing nervous system in infants and children.

For Consumer Reports to deem a fruit or vegetable high risk, only a relatively small proportion of samples had to be contaminated. The testing involved hundreds of samples for each food collected from US supermarkets over seven years. Only 4% of green bean samples tested had high-risk levels of pesticides.

But some of the levels found on contaminated beans were alarming: one green bean sample from 2022 had levels of methamidophos that were 100 times the level Consumer Reports’ scientists consider safe. Methamidophos has been banned in the US and on green bean imports for over a decade, raising questions about why it’s still showing up in supermarket produce.

It’s important to note that Consumer Reports scientists have stricter standards for what they consider safe than those of the Environmental Protection Agency – the US government body that sets the levels, known as tolerances. The Alliance for Food and Farming, a farming industry organization, notes that 99% of vegetables tested by the USDA meet government safety standards for pesticide residue. But many scientists – including those behind the Consumer Reports study – believe the EPA tolerances are often set far too high, putting consumers at risk.

“A lot of these EPA tolerances aren’t consistent with the best science,” says Michael Hansen, a senior scientist at Consumer Reports. “They were set a number of years ago – and they don’t take into account situations where there are multiple pesticide residues on a single sample. The data are now available – and the computing power is now there – to more accurately assess the actual risk.”

The strongest evidence of the dangers posed by pesticides comes from farm workers and pesticide applicators, who are exposed to much higher levels of the chemicals when they are applied to crops. On-the-job exposure to pesticides has been linked to higher risk of Parkinson’s disease, several forms of cancer, diabetes and other health problems.

When it comes to consumers, the risks from eating foods contaminated by pesticides grow over time. For most of the population, a single serving of a contaminated fruit is unlikely to cause harm – but routine consumption of a contaminated fruit or vegetable over months or years magnifies the risk.

Children and pregnant women are particularly vulnerable because some pesticides can be endocrine disruptors, which may interfere with hormones responsible for the development of key bodily systems, especially the reproductive system.

Over the next year, the Guardian will be partnering with Consumer Reports to dig more deeply into the findings of this study, seeking answers as to how the US food supply became contaminated by pesticides and what we can do about it.

Read more from this pesticide investigation:

When it comes to healthy eating, fruits and vegetables reign supreme. But along with all their vitamins, minerals and other nutrients can come something else: an unhealthy dose of dangerous pesticides.

Though using chemicals to control bugs, fungi and weeds helps farmers grow the food we need, it’s been clear since at least the 1960s that some chemicals also carry unacceptable health risks. And although certain notorious pesticides, such as DDT, have been banned in the US, government regulators have been slow to act on others. Even when a dangerous chemical is removed from the market, chemical companies and growers sometimes just start using other options that may be as dangerous.

Consumer Reports, which has tracked the use of pesticides on produce for decades, has seen this pattern repeat itself over and over. “It’s two steps forward and one step back – and sometimes even two steps back,” says James E Rogers, who oversees food safety at Consumer Reports.

To get a sense of the current situation, Consumer Reports recently conducted our most comprehensive review ever of pesticides in food. To do it, we analyzed seven years of data from the US Department of Agriculture, which each year tests a selection of conventional and organic produce grown in or imported to the US for pesticide residues. We looked at 59 common fruits and vegetables, including, in some cases, not just fresh versions but also canned, dried or frozen ones.

Our new results continue to raise red flags.

Pesticides posed significant risks in 20% of the foods we examined, including popular choices such as bell peppers, blueberries, green beans, potatoes and strawberries. One food, green beans, had residues of a pesticide that hasn’t been allowed to be used on the vegetable in the US for over a decade. And imported produce, especially some from Mexico, was particularly likely to carry risky levels of pesticide residues.

But there was good news, too. Pesticides presented little to worry about in nearly two-thirds of the foods, including nearly all of the organic ones. Also encouraging: the largest risks are caused by just a few pesticides, concentrated in a handful of foods, grown on a small fraction of US farmland. “That makes it easier to identify the problems and develop targeted solutions,” Rogers says – though he acknowledges that it will take time and effort to get the Environmental Protection Agency, which regulates the use of pesticides on crops, to make the necessary changes.

In the meantime, our analysis offers insights into simple steps you can take to limit exposure to harmful pesticides, such as using our ratings to identify which fruits and vegetables to focus on in your diet, and when buying organic produce can make the most sense.

What’s safer, what’s risky, and why

Sixteen of the 25 fruits and 21 of the 34 vegetables in our analysis had low levels of pesticide risk. Even children and pregnant people can safely eat more than three servings a day of those foods, Consumer Reports’ food safety experts say. Ten foods were of moderate risk; up to three servings a day of them are OK.

The flip side: 12 foods presented bigger concerns. Children and pregnant people should consume less than a serving a day of high-risk fruits and vegetables, and less than half a serving a day of very high-risk ones. Everyone else should limit consumption of those foods, too.

To come up with that advice, we analyzed the USDA’s test results for 29,643 individual food samples. We rated the risk of each fruit or vegetable by factoring in how many pesticides showed up in the food, how often they were found, the amount of each pesticide detected and each chemical’s toxicity.

The Alliance for Food and Farming, a farming industry organization, pointed out to Consumer Reports that more than 99% of foods tested by the USDA contained pesticide residues below the Environmental Protection Agency’s legal limits (referred to as tolerances).

But Consumer Reports’ scientists think many EPA tolerances are set too high. That’s why we use lower limits for pesticides that can harm the body’s neurological system or are suspected endocrine disruptors (meaning they may mimic or interfere with the body’s hormones). Consumer Reports’ approach also accounts for the possibility that other health risks may emerge as we learn more about these chemicals.

“The way the EPA assesses pesticide risk doesn’t reflect cutting-edge science and can’t account for all the ways the chemicals might affect people’s health, especially given that people are often exposed to multiple pesticides at a time,” says Consumer Reports senior scientist Michael Hansen. “So we take a precautionary approach, to make sure we don’t underestimate risks.”

In our analysis, a fruit or vegetable can contain several pesticides but still be considered low-risk if the combination of the number, concentration and toxicity of them is low. For example, broccoli fared well not because it had no pesticide residues but because higher-risk chemicals were at low levels and on just a few samples.

Some of the most problematic foods, on the other hand, had relatively few residues but worrisome levels of some high-risk pesticides.

Case in point: watermelon. It’s very high-risk mainly because of a pesticide called oxamyl. Only 11 of 331 conventional, domestic watermelon samples tested positive for oxamyl. But it’s among those that Consumer Reports’ experts believe require extra caution because of their potential for serious health risks.

Green beans are another example. They qualify as high-risk primarily because of a pesticide called acephate or one of its breakdown products, methamidophos. Only 4% of conventional, domestic green bean samples were positive for one or both – but their pesticide levels were often alarmingly high. In one sample from 2022 (the most recent year for which data was available), methamidophos levels were more than 100 times the level Consumer Reports’ scientists consider safe; in another, acephate levels were seven times higher. And in some 2021 samples, levels were higher still.

This is especially troubling because neither chemical should be on green beans at all: growers in the US have been prohibited from applying acephate to green beans since 2011, and methamidophos to all food since 2009.

“When you grab a handful of green beans at the supermarket or pick out a watermelon, your chance of getting one with risky pesticide levels may be relatively low,” Rogers says. “But if you do, you could get a much higher dose than you should, and if you eat the food often, the chances increase.”

In some cases a food qualifies as high-risk because of several factors, such as high levels of a moderately dangerous pesticide on many samples. Example: chlorpropham on potatoes. It’s not the most toxic pesticide – but it was on more than 90% of tested potatoes.

How pesticides can harm you

Pesticides are one of the only categories of chemicals we manufacture “specifically to kill organisms”, says Chensheng (Alex) Lu, an affiliate professor at the University of Washington in Seattle who researches the health effects of pesticide exposure. So it’s no surprise, he says, that pesticides used to manage insects, fungi and weeds may harm people, too.

While there are still open questions about exactly how and to what extent chronic exposure to pesticides can harm our health, scientists are piecing together a compelling case that some can, drawing on a mix of laboratory, animal and human research.

One type of evidence comes from population studies looking at health outcomes in people who eat foods with relatively high pesticide levels. A recent review in the journal Environmental Health, which looked at six such studies, found evidence linking pesticides to increased risks of cancer, diabetes and cardiovascular disease.

Stronger evidence of pesticides’ dangers comes from research looking at people who may be particularly vulnerable to pesticides, including farm workers and their families. In addition to the thousands of workers who become ill from pesticide poisonings every year, studies have linked on-the-job use of a variety of pesticides with a higher risk of Parkinson’s disease, breast cancer, diabetes and many more health problems.

Other research found that exposure during pregnancy to a common class of pesticides called organophosphates was associated with poorer intellectual development and reduced lung function in the children of farm workers.

Pregnancy and childhood are times of particular vulnerability to pesticides, in part because certain pesticides can be endocrine disruptors. Those are chemicals that interfere with hormones responsible for the development of a variety of the body’s systems, especially reproductive systems, says Tracey Woodruff, a professor of environmental health sciences at the University of California, San Francisco.

Another concern is that long-term exposure to even small amounts of pesticides may be especially harmful to people with chronic health problems, those who live in areas where they are exposed to many other toxins and people who face other social or economic health stresses, says Jennifer Sass, a senior scientist at the Natural Resources Defense Council.

That’s one of the reasons, she says, regulators should employ extra safety margins when setting pesticide limits – to account for all the uncertainty in how pesticides might harm us.

How to stop eating pesticides

While our analysis of USDA pesticide data found that some foods still have worrisome levels of certain dangerous pesticides, it also offers insights into how you can limit your pesticide exposure now, and what government regulators should do to fix the problem in the long term.

Eat lots of low-risk produce. A quick scan of this chart makes one thing clear: there are lots of good options to choose from.

“That’s great,” says Amy Keating, a registered dietitian at Consumer Reports. “You can eat a variety of healthy fruits and vegetables without stressing too much about pesticide risk, provided you take some simple steps at home.” (See Can you wash pesticides off your food? A guide to eating fewer toxic chemicals.)

Your best bet is to choose produce rated low-risk or very low-risk in our analysis and, when possible, opt for organic instead of riskier foods you enjoy. Or swap in lower-risk alternatives for riskier ones. For example, try snap peas instead of green beans, cantaloupe in place of watermelon, cabbage or dark green lettuces for kale, and the occasional sweet potato instead of a white one.

But you don’t need to eliminate higher-risk foods from your diet. Eating them occasionally is fine.

“The harm, even from the most problematic produce, comes from exposure during vulnerable times such as pregnancy or early childhood, or from repeated exposure over years,” Rogers says.

Switch to organic when possible. A proven way to reduce pesticide exposure is to eat organic fruits and vegetables, especially for the highest-risk foods. We had information about organically grown versions for 45 of the 59 foods in our analysis. Nearly all had low or very low pesticide risk, and only two domestically grown varieties – fresh spinach and potatoes – posed even a moderate risk.

Organic foods’ low-risk ratings indicate that the USDA’s organic certification program, for the most part, is working.

Pesticides aren’t totally prohibited on organic farms, but they are sharply restricted. Organic growers may use pesticides only if other practices – such as crop rotation – can’t fully address a pest problem. Even then, farmers can apply only low-risk pesticides derived from natural mineral or biological sources that have been approved by the USDA’s National Organic Program.

Less pesticide on food means less in our bodies: multiple studies have shown that switching to an organic diet quickly reduces dietary exposure. Organic farming protects health in other ways, too, especially of farm workers and rural residents, because pesticides are less likely to drift into the areas where they live or to contaminate drinking water.

And organic farming protects other living organisms, many of which are even more vulnerable to pesticides than we are. For example, organic growers can’t use a class of insecticides called neonicotinoids, a group of chemicals that may cause developmental problems in young children – and is clearly hazardous to aquatic life, birds and important pollinators including honeybees, wild bees and butterflies.

The rub, of course, is price: organic food tends to cost more – sometimes much more.

“That’s why, while we think it’s always worth considering organic produce, it’s most important for the handful of fruits and vegetables that pose the greatest pesticide risk,” Rogers says. He also says that opting for organic is most crucial for young children and during pregnancy, when people are extra vulnerable to the potential harms of the chemicals.

Watch out for some imports. Overall, imported fruits and vegetables and those grown domestically are pretty comparable, with roughly an equal number of them posing a moderate or worse pesticide risk. But imports, particularly from Mexico, can be especially risky.

Seven imported foods in our analysis pose a very high risk, compared with just four domestic ones. And of the 100 individual fruit or vegetable samples in our analysis with the highest pesticide risk levels, 65 were imported. Most of those – 52 – came from Mexico, and the majority involved strawberries (usually frozen) or green beans (nearly all contaminated with acephate, the pesticide that’s prohibited for use on green beans headed to the US).

A spokesperson for the Food and Drug Administration told Consumer Reports that the agency is aware of the problem of acephate contamination on green beans from Mexico. Between 2017 and 2024, the agency has issued import alerts on 14 Mexican companies because of acephate found on green beans. These alerts allow the FDA to detain the firms’ food shipments until they can prove the foods are not contaminated with the illegal pesticide residues in question.

The Fresh Produce Association of the Americas, which represents many major importers of fruits and vegetables from Mexico, did not respond to a request for comment.

Rogers, at Consumer Reports, says: “Clearly, the safeguards aren’t working as they are supposed to.” As a result, “consumers are being exposed to much higher levels of very dangerous pesticides than they should.” Because of those risks, he suggests checking packaging on green beans and strawberries for the country of origin, and consider other sources, including organic.

How to solve the pesticide problem

Perhaps the most reassuring, and powerful, part of Consumer Reports’ analysis is that it demonstrates that the risks of pesticides are concentrated in just a handful of foods and pesticides.

Of the nearly 30,000 total fruit and vegetable samples Consumer Reports looked at, just 2,400, or about 8%, qualified as high-risk or very high-risk. And among those samples, just two broad classes of chemicals, organophosphates and a similar type of pesticide called carbamates, were responsible for most of the risk.

“That not only means that most of the produce Americans consume has low levels of pesticide risk, but it makes trying to solve the problem much more manageable, by letting regulators and growers know exactly what they need to concentrate on,” says Brian Ronholm, head of food policy at Consumer Reports.

Organophosphates and carbamates became popular after DDT and related pesticides were phased out in the 1970s and 1980s. But concerns about these pesticides soon followed. While the EPA has removed a handful of them from the market and lowered limits on some foods for a few others, many organophosphates and carbamates are still used on fruits and vegetables.

Take, for instance, phosmet, an organophosphate that is the main culprit behind blueberries’ poor score. Until recently, phosmet rarely appeared among the most concerning samples of pesticide-contaminated food. But in recent years, it’s become a main contributor of pesticide risk in some fruits and vegetables, according to our analysis.

“That’s happened in part because when a high-risk pesticide is banned or pushed off the market, some farmers switch to a similar one still on the market that too often ends up posing comparable or even greater harm,” says Charles Benbrook, an independent expert on pesticide use and regulation, who consulted with Consumer Reports on our pesticide analysis.

Consumer Reports’ food safety experts say our current analysis has identified several ways the EPA, FDA and USDA could better protect consumers.

That includes doing a more effective job of working with agricultural agencies in other countries and inspecting imported food, especially from Mexico, and conducting and supporting research to more fully elucidate the risks of pesticides. In addition, the government should provide more support to organic farmers and invest more federal dollars to expand the supply of organic food – which would, in turn, lower prices for consumers.

But one of the most effective, and simple, steps the EPA could take to reduce overall pesticide risk would be to ban the use of any organophosphate or carbamate on food crops.

The EPA told Consumer Reports that “each chemical is individually evaluated based on its toxicity and exposure profile”, and that the agency had required extra safety measures for several organophosphates.

But Consumer Reports’ Ronholm says that approach is insufficient. “We’ve seen time and again that doesn’t work. Industry and farmers simply hop over to another related chemical that may pose similar risks.”

Canceling two whole classes of pesticides may sound extreme. “But the vast majority of fruits and vegetables eaten in the US are already grown without hazardous pesticides,” Ronholm says. “We just don’t need them. And the foods American consumers eat every day would be much, much safer without them.”

Read more from this pesticide investigation:

Find out more about pesticides at Consumer Reports

Attention home cooks: do you, like me, have half a lemon, perhaps encased in a beeswax wrap or clingfilm, sitting in your fridge? Half a cucumber, going dry at one end? Or maybe an open jar of capers, barely used, but well past the two-week recommended refrigeration period? So often, a recipe requires just half an onion, or a third of a block of tofu – especially when cooking for one.

According to the 2024 UN Food Waste Index report, about a fifth of the world’s food is wasted. Worldwide, households are responsible for the majority of it: about 60% of the 1bn tonnes of food thrown away annually. So how best to keep your leftover food fresh – and for how long does it remain safe to eat?

1. Avocado

Earlier this year, the food magazine Bon Appétit tackled the pressing question of how best to store half an avocado. Its advice was to remove the pit, leave the skin on and place it cut-side down on a plate. Using lemon or lime juice on the cut side, or wrapping the whole thing in clingfilm, can also help to minimise oxidation, which is what causes avocado flesh to turn grey and mushy.

2. Tofu

Firm tofu keeps better than the silken variety for leftovers, according to Amy Poon, the founder of the Chinese restaurant Poon’s London. “Tofu should keep for two to three days if stored in a plastic container, submerged in clean, cold water (not the water it comes in), but you should change the water daily,” she says. “You can also freeze tofu.”

3. Tinned goods

Tins are a big fridge no-no since, once opened, the tin from the can can transfer more quickly to the contents, according to the Food Standards Agency. Many tinned items – such as baked beans or coconut milk – are also available in half-size cans, which may be more suitable for using as part of a meal for one, although they are rarely the most economical option. James Cooper, the deputy director of food policy at the FSA, advises emptying leftover contents into a bowl or airtight container before storing it in the fridge. “Use a clean cover that is suitable for food to protect the contents from drips and spills, and use within two days or freeze if you think this won’t be possible,” he says.

4. Lemon wedges

Often, leftover lemon wedges can simply be served alongside whichever dish they have been partially used to season – but what about for drinks? “Cut fruit is a tricky one,” says Will Meredith, a beverage consultant for restaurants including Fenix in Manchester and Tattu (nationwide). “Citrus will oxidise very quickly due to all the sugar and acid – you can only expect to use slices or wedges on the day you cut them. To keep them looking and feeling fresh, place in a bowl filled with crushed or shaved ice – like you see in a fish market.”

5. Pancake batter

Fancy pancakes two days on the trot? You’re in luck! Joe Fox, the executive head chef for Firmdale Hotels, assures me that batter will keep – “although it may separate a little bit, so you’ll need to give it a good mix”, he says. “I’d transfer it straight away into an airtight container or a jam jar in the fridge, otherwise the air can cause it to discolour, which can be off-putting.”

6. Eggs

At least pancakes use whole eggs – what of recipes that require only the yolks or the whites? Rachel Morgan, co-founder of Twelve Triangles bakery in Edinburgh, keeps leftovers in a plastic container or a bowl covered in clingfilm. “Whites I’ve kept for about 10 days in the fridge; yolks tend to keep not so well and form a bit of skin, so if you have any to store I would freeze them instead,” she suggests.

7. Things in brine

I could probably eat a whole jar of olives in one sitting, but capers and cornichons are more persistent fridge-lingerers. How best to make them last? “Once opened, you want to avoid as much oxygen as possible getting into the jars, as that will create mould and foul odours,” says Meredith. “The simplest thing is get some baking paper, cut a disc large enough to cover the liquid in the jar and pat it down to create a block between the ingredients and the lid. This will prevent oxygen tainting those lovely olives, pickles or any other jarred goods.” He recommends keeping brined foods refrigerated if possible, but it’s not essential (although the storage instructions may disagree).

8. Juice

This is a complicated one – is your juice fresh? From concentrate? Pasteurised? Some unopened shop-bought juices can be kept for many months, but most have a relatively short shelf life once the seal has been broken. The FSA is strict on this: it recommends “reading the label and following the manufacturer’s instructions” – which often means consuming within three to five days. Eat By Date – “a group of contributors from the kitchen and classroom communities who set out to answer the question, ‘How long does food really last?’” – go by brand, advising that refrigerated Welch’s grape juice, for example, is safe to consume seven to 10 days after opening, while Ocean Spray cranberry juice lasts two to three weeks.

9. Non-dairy milk

“They just keep going, don’t they?” says Fox. Anyone who has made the switch from dairy will have noticed that alternative milks often seem to last well beyond the recommended five or so days in the fridge. “You could decant the milk into a glass bottle but it is kind of designed to be stored in the carton,” he says. “I feel like oat and almond milk last the longest – things like soya turn quicker. If you do store it in glass, you will be better able to see if the milk has split, but a good shake would probably bring it back together; you can taste if it’s gone bad.”

10. Bread

“If bread gets warm in a bread bin, it’ll be more likely to go mouldy, as any moisture in it will condense,” says Morgan. Instead, she keeps hers in a cotton or paper bag. But what if mould has already appeared – just a tiny bit on the crust, perhaps? Can you just slice it off and salvage the rest? “I wouldn’t,” she says. Most experts seem to agree, since, although only a few spots may be visible, porous food such as bread can be contaminated beneath the surface – which is enough to put anyone off their toast. However, you can also freeze bread for greater longevity.

11. Cucumber

Is there a way to avoid throwing out that dried-out end slice? “Once cut, I keep cucumber in an airtight container, lined with a little kitchen paper or a clean tea towel [in the fridge],” says Melissa Hemsley, the author of cookbooks including Feel Good and the forthcoming Real Healthy. “If you do feel the need to chop off the end, you only need to slice the thinnest round off. Also, cook with cucumber! If your remaining half is a touch less than fresh, I like to stir-fry it with sesame oil, garlic and chilli.”

12. Cheese

From roquefort to red leicester, Hemsley has useful advice about open packets of cheese: “Beeswax wraps or silicone reusable bags are really handy, or seal the packaging with elastic bands,” she suggests. Cheese buyer Dan Bliss wraps her cheese in wax or baking paper, stores it in a plastic container in the fridge – and suggests adding a sugar cube to the pot, to suck up any excess moisture. Unlike bread, if your cheese decides to sprout mould, that doesn’t necessarily mean it’s game over – especially if it’s hard cheese.

13. Open packets of wraps/naans

Again, preventing moisture is key to longevity. Morgan wraps open packs of naan or tortilla wraps in clingfilm before storing somewhere dry, while Eat By Date suggests tortillas “generally last for a week after their ‘best by’ date on the counter and about a month if placed in the fridge”.

14. Things in jars

For me, this comprises almost an entire fridge shelf: harissa, tomato puree, pesto, gochujang and curry pastes can all sit for weeks – perhaps longer – used once, then abandoned. I refuse to let them go to waste and yet, according to Leonard Tanyag, the executive chef at Los Mochis London City, I am doing it all wrong if I want them to remain fit for consumption: really, they shouldn’t be left in their jars at all. “Once opened, transfer to an airtight container to maintain their freshness and add some oil on top to prevent air exposure, which makes it last for weeks,” he says. And, of course, you should “always check or smell the opened paste before use for any signs of spoilage”.

15. Half an onion

Onions are a little like avocados in terms of maintaining freshness: keep the skin on the half you’re not using, then place cut-side down on a plate in the fridge. “If you don’t know when you’re next going to use the leftover onion, chop it and freeze it,” suggests Hemsley. “Then you’ve got it ready to go in a future pasta sauce or soup or stir fry.”

16. Fresh herbs

Whether it’s mint for your mojito or coriander for your tacos, fresh herbs can bring a recipe to life – but they also wilt fast. “Wrap them in damp blue cloths or kitchen roll and keep in the fridge,” suggests Meredith. “Doing this will extend the shelf life by several days.”

17. Jams and chutneys

“Try to always use a clean spoon – double dipping will increase the bacteria risk,” explains Fox, who tells me he has a chutney in his fridge from during the pandemic and it’s “still going, still tasty”. Lillie O’Brien, the owner of small-batch jam and marmalade makers London Borough of Jam, recommends refrigerating jams and preserves after opening, although “if you are going to eat them quickly and it’s not summer, then they will be fine left on a kitchen bench for a week or two”. Products that are lower in preserving agents could go mouldy if left out longer, she says.

18. Salad

“Heads of lettuce generally last much better than bagged leaves,” says Hemsley. Like cucumber, she stores salad in the fridge in an airtight container lined with kitchen paper or a clean tea towel to absorb any excess moisture. “If salad has gone a bit wilted and sad, you can revive the leaves by putting them in a big bowl of iced water for 10-15 minutes, then drain and dry in a salad spinner,” she suggests. “If you have a few rogue soggy leaves, remove them so they don’t infiltrate the rest of the lettuce.”

Perched on a quay in the Cornish port of Falmouth is Pysk fishmongers, where Giles and Sarah Gilbert started out with a dream to supply locally caught seafood to the town. Their catch comes mainly from small boats that deliver a glittering array of local fish: gleaming red mullets, iridescent mackerels, spotted dabs and bright white scallops, still snapping in their shells.

Occasionally, they will get a treasured haul of local common prawns – stripy, smaller and sweeter than the frozen, imported varieties in UK supermarkets. So, when customers come into the shop asking for prawns, Giles Gilbert presents “these bouncing jack-in-a-boxes” with a flourish, hoping to tempt buyers with the fresh, live shellfish.

“I think most people are absolutely fascinated,” he says. “But they’ll say, ‘Have you got anything a bit bigger than that?’ or, ‘I wanted something that was already cooked.’”

Time and again, Gilbert finds himself rummaging around in the freezer to retrieve an emergency bag of imported shellfish, lest he lose a loyal customer.

It’s not just prawns. “We have access to some incredible fish, but it stays on the counter because what people are looking for is cod or salmon, when there’s this immaculate fish that’s been caught maybe an hour ago,” he says.

“It’s frustrating when we’ve developed relationships with fishermen and we can’t take their entire catch.”

The UK is perhaps unfairly stereotyped as a nation with an unadventurous palate. But where seafood is concerned, that’s backed up by the data. There are more than 300 species in the UK’s coastal waters, and British people eat strikingly little of it.

According to Seafish, the UK public body supporting the industry, the UK’s “big five” – cod, pollack, salmon, tuna and prawns – comprise 62% of seafood consumed in Britain (though the Marine Stewardship Council names the big five as cod, haddock, salmon, tuna and prawns, and reckons they make up 80% of fish and seafood eaten in the UK when consumption outside the home, in restaurants and in fish ‘n’ chip shops is included).

Most of what is eaten in the UK is imported, while the majority of what is fished in British waters is sent elsewhere.

It’s not just the UK. In the European Union, cod, pollack, salmon, tuna and prawns account for 44% of consumption. In the US, as well as these five, the 10 most popular species include tilapia, clams and catfish, accounting for 76% of seafood.

Our global eating patterns increasingly tend towards fewer and larger species, consumed further from where they are caught.

Those dietary choices fuel problems such as overfishing, resource-intensive fish farms, higher greenhouse-gas emissions, and tonnes of fish waste. The percentage of populations fished at biologically unsustainable levels is increasing worldwide, according to a recent UN report, while our appetite for seafood is also likely to grow.

The picture appears bleak – and yet, if selected and consumed carefully, seafood provides a powerful opportunity to improve the environmental impact of our diets overall.

“Seafood can be, and in some situations is being, produced very sustainably, especially when compared to other terrestrial animal-source foods,” says Jessica Gephart, an expert in the globalisation of aquatic food at the University of Washington.

What’s on our plates – and why?

So, can we shift our diehard eating habits towards new fish? And why do we prefer cod over cockles, and salmon rather than sole? It’s a complex global picture, starting with the UK, where people once ate a wider variety of seafood, including an abundance of sprats, herring and whelks. Essex University led research published last year that offered clues about why these patterns have changed.

From the early 1900s, industrialised fishing fuelled the expansion of British boats beyond inshore waters into plentiful northern seas, where they began scooping up several hundreds of thousands tonnes of haddock and cod. Cue the spread of fish ’n’ chip shops, which found a convenient vehicle for their batter in these large, filleted and less bony fish.

After 1973, when the UK joined the European Economic Community, British boats lost access to more distant fishing grounds and became confined to inshore waters, where those big white fish were less abundant. But by this point, the national preference for haddock and cod was entrenched, and the UK began importing these species to fill the deficit.

“So the situation we’re in today is that we import a lot of the seafood that we consume, including those ‘big five’ species, and we export most of what we land,” says Luke Harrison, who led the Essex University study. In fact, between 1975 and 2019, the share of British fish consumed by the UK public dropped from 89% to 40%, his research showed.

Our palates have also been dulled by how we shop. Jack Clarke, seafood engagement manager at the Marine Conservation Society (MCS), says: “The homogenisation of our diet, especially around seafood, is probably due to our over-reliance on supermarkets.”

Big chains need to secure large and consistent supplies of easily processable seafood, which usually creates a bias towards a smaller number of fish from bigger species that are caught by larger fisheries, he says. This could increase pressure on wild stocks or push retailers towards species raised in fish farms.

The simplifying effect of our globalised food system is most obvious in wealthy countries. Anna Sturrock, an aquatic ecologist at Essex University, and a co-author of the study, says: “We can afford these imports. That’s probably the main reason it hasn’t changed: we’ve got a taste for it, and it’s always been available to us.”

That is echoed in the US, where prawns make up more than 30% of Americans’ annual consumption of seafood. About 90% are imported from countries such as Indonesia and India, where the farming of prawns has been implicated in labour abuses and the destruction of mangroves. Yet US-caught prawns met half of the national demand in the 1980s.

Even as one of the top six seafood producers worldwide, the US imports about 65% of what it consumes. “US seafood consumption is dominated by a few species,” says Gephart. “A significant share of that also comes from canned and processed forms, like frozen breaded patties.”

Research by Seafish shows that convenience is a key driver of consumer choices in Britain, and our impoverished palates as a result may help explain why we have lost our taste for kippers and turn up our noses at the mussels that are abundant off UK shores.

David Willer, at Cambridge University, has researched underexploited seafood, such as mussels. “We’ve done lots of research on that, and it’s mostly down to convenience and ease of preparation, and a kind of ‘yuck’ factor,” he says.

In India, another top global producer of fish, tropical waters support a great diversity of species, but in lower quantities. As Divya Karnad, a marine geographer and conservationist at Ashoka University, near Delhi, explains, that means a fisher who catches 100 local fish is likely to have several dozen species in his net.

“Historically, coastal India had ways of dealing with this, either by having recipes specifically for different fish, or having a generic recipe in which they could add many species,” she says.

But with an increasingly urbanised population in India, she adds: “People don’t have enough time to handle their food. So instead of cleaning hundreds of small fish, if you can get a fillet then you will choose that.”

Karnad’s research has drawn a link between this more selective diet and overfishing. Picture that fisherman hauling in his catch of 100 diverse fish, she says. “But now, he’s able to sell only 15. So he has to go out that many more times to actually make up the cost.”

She also believes there is an aspirational quality attached to some fish species, such as Norwegian salmon, which is now in demand among wealthy people. This fish is now ubiquitous globally, says Shakuntala Haraksingh Thilsted, global lead for nutrition and public health at WorldFish, which aims to reduce hunger, malnutrition and poverty across Africa, Asia and the Pacific through sustainable aquaculture.

Thilsted, the 2021 recipient of the World Food Prize, found salmon on sale even in the diverse seafood markets of Thailand. Japan did not use salmon in sushi a few decades ago but now it’s everywhere, she says, swaddled in blankets of sticky rice.

“That has something to do with the power of the private market – that foods that are considered desirable, aspirational, have moved across borders,” Thilsted says.

What should be on our plates?

How do we begin to disentangle these patterns to eat more sustainably? There is no magic bullet for something as complicated as seafood, says Sturrock at Essex University, adding: “When we think about sustainability, it’s not just about overfishing, it’s also about how far we bring it from different places, and the impact of that fishery, or the aquaculture type, on the local environment.”

There is also the issue of fish waste as well as social factors – labour rights, fishers’ livelihoods – embedded in our choice of fish.

And there are trade-offs. A local, small-scale fishery may still be putting pressure on a delicate population, while a more distant fishery might have higher carbon emissions but be exploiting a more stable population.

Even farmed salmon, with all its problems, is not so clearcut when emissions from its production are lower than those associated with chicken, and improvements in breeding and feed are bringing those emissions down further, says Gephart, at the University of Washington. This can make sustainable eating feel like a game of Whac-A-Mole. “It is really hard and unreasonable to put that on consumers,” she says.

Governments do need to make better decisions about where and what is fished, and how to support fishers to work more sustainably in a difficult industry. However, “that doesn’t mean that we should throw up our hands and say that ‘seafood is bad, it’s all too complicated’,” Gephart says.

“It’s about how we signal our values for sustainable production, so that we can lean on industry and governments.”

Clarke, at the MCS, suggests getting guidance on what populations are green-rated, or to find alternatives, from sources such as its own Good Fish Guide or Seafood Watch, produced by the US not-for-profit organisation Monterey Bay Aquarium.

For instance, for those wanting a change from salmon, which makes up almost a third of all fish eaten in the UK, farmed trout has fewer pollution issues and also uses less fish in the feed, Clarke says. “And they’re really tasty, with a similar flavour profile to salmon, and just as simple to cook.”

If you live close to a fishmonger, tap into their knowledge too, he adds. They will also have a more diverse array of fish than most supermarkets.

“If we make room for diverse foods on the plate, then we will be getting closer to the goals we aspire to,” says Thilsted. Eating a wider variety of fish takes pressure off certain populations, and shift our diets towards smaller species that are green-rated, such as herrings and sardines, which can be eaten whole, thereby helping tackle fish waste.

It also shifts the spotlight on to shellfish and bivalves such as mussels. If there is one seafood with almost universal environmental credibility, this is it, says Gephart, whose research shows that of all aquatic foods, farmed mussels and seaweeds have the lowest environmental impact. Together, they can create refuges for ocean species, while mussels also have protein levels similar to beef.

The challenge now is increasing consumer demand, says Willer, at Cambridge University. He is working with the food industry on innovative projects to make mussels, for instance, more palatable to the British public.

Others are taking the more futuristic leap into lab-grown seafood to relieve pressure on overfished populations. Meanwhile, others are working to build sustainability across the wider industry. In India, Karnad set up InSeason Fish, which works with restaurants to raise awareness of fish to avoid and to promote alternatives, depending on the region and month.

“We realised that in culinary institutes in India, chefs were not being trained with indigenous ingredients. They were instead learning about French cuisine,” says Karnad, whose organisation trains chefs in how to prepare India’s diverse fish. It has also brought in local fishers directly to advise chefs on the incoming catch and procure what they need.

In another attempt to diversify menus, a British company called CH&Co, which caters for venues including schools, hospitals, and offices, is focused on reducing the use of the big five. They provide their clients with data about the proportion of big five species that they are buying, and then take steps to educate and challenge their culinary teams to reduce the use of these fish.

As a result, “chefs are putting more diverse species at the centre of menus and working to change customer attitudes to what fish species should appear on a plate”, says Clare Clark, the head of sustainability at CH&Co.

The changing face of sustainable seafood has provided new ways to “vote with your wallet”, says Jack Clarke, adding: “It really does have an effect.”

In Cornwall, Gilbert is seeing people doing exactly that. In a recent experiment, he displayed three types of scallops on his fish counter, each with the catch method and sustainability information supplied alongside the price. To his surprise, he found customers preferred the most expensive but sustainable hand-dived scallops.

He may not have won them over on the local prawns yet. But he senses that the tide is turning: “We just seem to have more and more interest in what we’re doing here.”

The deadly protracted heatwave that filled hospitals and mortuaries in the Sahel region of Africa earlier this month would have been impossible without human-caused climate disruption, a new analysis has revealed.

Mali registered the hottest day in its history on 3 April as temperatures hit 48.5C in the south-western city of Kayes. Intense heat continued across a wide area of the country for more than five days and nights, giving vulnerable people no time for recovery.

In the capital, Bamako, the Gabriel-Touré hospital reported 102 deaths over the first four days of April, almost as many as there had been over the entire month last year. More than half the dead were over the age of 60 and many of the deaths were related to heat, the hospital said.

Local news reports said mortuaries in Bamako were so full that many people had had to keep their dead relatives at home.

The health impacts may have been compounded by electricity shortages, which left many people without fans and air conditioning units. Regional media have reported that the national energy company, EDM, is struggling to pay a £410m fuel bill for its power plants.

Local populations may also have been made more susceptible because the heatwave coincided with the end of Ramadan, when many Muslims fast during the day and consume food and water only in the early morning or at night.

The full death toll is hard to calculate due to a lack of data from the countries affected, but the study, by a team of international scientists, said there had probably been hundreds or possibly thousands of other heat-related deaths.

The analysis, by World Weather Attribution, found that maximum temperatures in Burkina Faso and Mali had been made 1.5C hotter by climate breakdown, which is caused by the burning of gas, oil, coal and trees – particularly in the wealthy northern hemisphere. The same factors had pushed up nighttime temperatures by 2C, researchers said.

In the broader region, the study found the five-day heatwave would have been 1.5C cooler without human influence on the climate.

Kiswendsida Guigma, a climate scientist at the Red Cross Red Crescent Climate Centre in Burkina Faso, said people in the Sahel and other parts of west Africa were accustomed to year-round heat, but that April’s temperatures had been unprecedented: “For some, a heatwave being 1.4 or 1.5C hotter because of climate change might not sound like a big increase, but this additional heat would have been the difference between life and death for many people.”

Mali and Burkina Faso would normally expect such protracted high daytime temperatures around once in every 200 years. The study forecasts they will become 10 times more frequent if global warming reaches 2C above preindustrial levels, as is expected to occur in the 2040s or 2050s if emissions are not rapidly halted.

The El Niño phenomenon has been driving up temperatures worldwide over the past year, but researchers found that El Niño’s effect was negligible in Mali and Burkina Faso compared with human-caused global heating.

Other studies have underlined how the countries least responsible for the climate crisis are suffering many of the worst effects of it. In March, the southern coastal zone of western Africa experienced average heat index temperatures, which include humidity, of 50C, which is considered dangerous. In some areas, this rose as high as 60C, classified as “extreme danger”.

An analysis of this event by World Weather Attribution found that human-induced global heating had pushed up temperatures in the region on this occasion by 4C and made the combination of humidity and heat 10 times more likely.

The authors urged world leaders to curb emissions of gas, oil and coal as rapidly as possible to reduce future effects. They said local authorities should also prepare heat action plans so that hospitals, schools and vulnerable populations were prepared for heatwaves. They said fossil fuel companies should also be made more accountable.

“Extreme heat, driven by climate change, is resulting in death for vulnerable people. Attribution studies like this one clearly show that if the world continues to burn fossil fuels, the climate will continue to warm and vulnerable people will continue to die,” said Friederike Otto, senior lecturer in climate science at the Grantham Institute at Imperial College London.

“In the future, it’s likely this increasingly evident link between fossil fuel emissions and heat-related death will be used in litigation against fossil fuel companies.”

In a separate study released at the same time, World Weather Attribution found that El Niño, rather than human-induced climate breakdown, was the primary cause of the devastating drought in southern Africa earlier this year and advised governments in the region to bolster food security ahead of future El Niño years.

Bumblebees might be at home in town and country but now researchers have found at least one species that is even more adaptable: it can survive underwater.

Scientists have revealed queens of the common eastern bumblebee, a species widespread in eastern North America, can withstand submersion for up to a week when hibernating.

With bumblebee queens known to burrow into soil to hibernate, the researchers say the phenomenon could help them survive flooding in the wild.

The team said its next priority was to explore whether the results hold for other species of bumblebee.

“We know that about a third of all bumblebee species are in decline currently [but] it’s not the case with [the common eastern bumblebee],” said Dr Sabrina Rondeau of the University of Guelph in Canada, adding the team was keen to learn whether flood tolerance could play a role in their resilience.

Rondeau and her co-author, Prof Nigel Raine, first made their discovery when a mishap in the laboratory led to water getting into containers in which hibernating queen bees were kept.

“After that, of course, curiosity led the way to conducting a full experiment with a lot of repetitions,” said Rondeau.

Writing in the journal Biology Letters, the scientists describe how they took 143 unmated, hibernating queens of the common eastern bumblebee and placed each in its own plastic tube containing damp topsoil. The tubes were then fitted with perforated lids and kept in a dark refrigerated unit for a week.

After checking the bees were still alive, the researchers kept 17 tubes as controls and added cold water to the remaining 126. While the queen was allowed to float on top of the water in half of these tubes, it was pushed under the water by a plunger in the others.

For both conditions, a third of the tubes were each left for eight hours, a third for 24 hours and a third for seven days, simulating different flooding conditions. The team subsequently transferred the bees to new tubes and monitored their survival.

The results reveal survival rates were similar regardless of the duration and conditions the queens had been subjected to – indeed 88% of the controls, and 81% of the queens that were submerged for a week, were still alive at eight weeks. However, queens with a higher weight had a greater chance of survival.

The researchers say the findings are unusual given most insects overwintering as adults – including many ground beetles – cannot cope with being submerged in water and must leave floodplains to survive.

While Rondeau said it was likely queens of other bumblebee species were also flood tolerant, ground nesting bees – which include some species of bumblebee – could still be affected by flooding as their larvae may not survive.

Among future areas of research, the team said it would be interesting to explore the mechanisms that underpin the queens’ resilience to flooding – with their low oxygen requirements during hibernation among possible important factors.

Prof Dave Goulson, a bee expert from the University of Sussex who was not involved in the work, said bee enthusiasts had long speculated that increased winter rain amid the climate crisis could drown many queen bumblebees as they hibernate underground.

“Amazingly, this new research shows that hibernating queen bumblebees are entirely unaffected by being held under water for up to one week,” he said. “This seems to be one small aspect of climate change that we need not worry about.”

It was a relatively cool spring day in Phoenix, Arizona, as a tree-planting crew dug large holes in one of the desert city’s hottest and least shaded neighborhoods.

Still, it was sweaty backbreaking work as they carefully positioned, watered and staked a 10ft tall Blue palo verde and Chilean mesquite in opposite corners of resident Ana Cordoba’s dusty unshaded backyard.

“If I ever retire, I’d like to be able to spend more time outside. The weather is changing, so I am really happy to get these trees. We need more shade,” said Cordoba, 75, a legal secretary, whose family has lived in Grant Park for more than a century.

Over the course of three days in early April, arborists planted 40 or so desert adapted trees in Grant Park, as part of the city’s equity-driven heat mitigation plan to create a shadier, more livable environment amid rising temperatures and hundreds of heat-related deaths.

Phoenix is America’s fifth largest and hottest city, a sprawling urban heat island which has expanded without adequate consideration to climate and environmental factors like water scarcity and extreme heat. ​Multiple heat records were broken last year including 133 days over 100F (37.7C), and 55 days topping 110F (43C).

Only around 9% of Phoenix is protected by tree canopies, yet this citywide figure masks vast inequities between wealthy, majority-white neighborhoods like Willo (13% coverage) just two miles north of Grant Park (4%). One census tract in the north-west of the city, Camelback East, has 23% tree cover.

“This is one of the city’s oldest neighborhoods – and one of the most neglected,” said Silverio Ontiveros, a retired police chief turned community organizer who drummed up interest for the tree planting by knocking on doors and putting flyers through every neighbor’s letterbox.

“Our goal is to change the inequity and create enough shade to provide residents and passersby reprieve from the heat. For that we need many more trees, but we also need to take care of them,” added Ontiveros, as he walked through the neighborhood making sure the right families got the right trees.

Grant Park is a majority Latino community in south Phoenix situated next to a sprawling electrical substation – a hot and dusty neighborhood with ​​200 or so homes, but no stores and plenty of empty lots and boarded-up houses. It was once a thriving neighborhood – one of the few places where people of color could live due to discriminatory housing policies that lasted most of the 20th century.

Redlined neighborhoods like Grant Park still have higher pollution levels, less vegetation, more noise pollution and higher temperatures. In recent years, the local outdoor pool was shuttered and scores of trees cut down by a previous administration to prevent homeless people from gathering in the shade.

“This is one of the hottest parts of the city because the people here don’t have political power,” said Leo Hernandez, 78, the master gardener at the thriving community garden where he created a butterfly sanctuary for migrating monarchs. “We need shade, but trees also suck up carbon dioxide, create places to socialize and healthier, happier neighborhoods.”

Trees have multiple benefits in urban areas which include cleaner air, improved physical and mental health, water conservation, increasing wildlife habitat, CO₂ storage and sequestration and lower temperatures through shade.

The city is mostly concerned with reducing the urban heat island effect and improving public health, and its 2010 shade masterplan set out a goal of achieving 25% citywide canopy cover by 2030. Amid little progress and rising heat mortality and morbidity, in 2021 Phoenix established the country’s first office of heat response and mitigation. Its community tree planting program is now being rolled out to public schools, churches and homes in qualifying census tracts – low-income neighborhoods with little shade.

Residents can choose from a list of 19 native and desert-adapted trees including the Texas olive, Chinese red pistache and Chilean mesquites. The trees, which are a couple of years old and pretty heavy, are planted by contracted arborists. For insurance reasons, they must be within the property – not the sidewalk – and not too close to walls or power lines. Each household also gets a tree kit – a 100ft hose, irrigation timer and instrument to measure the soil pH and moisture, as well as written care instructions.

This is the fourth tree-planting initiative in Grant Park, but the other schemes involved donations of smaller, younger trees which residents themselves had to plant in the dry, rocky earth. Several didn’t survive last summer’s heatwave when temperatures hit 100F (37.7C) on 31 consecutive days, while others died from overwatering or a lack of attention.

Tree planting has become increasingly popular among corporations, governments and environmental groups alike in recent years, with mixed results. In Turkey, 90% of the government’s 11m new trees died within months, while polluting industries including mining and fossil fuel companies have been accused of trying to greenwash environmental and climate harms.

“It is very hard to grow trees here, our environment is very extreme, so we’re doing everything we can to help them survive, which includes giving people the choice so they have species they love and feel excited about,” said Kayla Killoren, the heat office tree equity project coordinator. “There’s been a lot of greenwashing, and some people are weary and think it’s a scam at first, until they see their neighbors get trees planted.”

In Phoenix, a 75 to 80% survival rate would be considered a success, according to Killoren.

So far, 700 trees have been planted with scores more events planned throughout April and May, and will resume again in the fall after the summer heat. The project is mostly funded through non-profits, local and federal government grants including millions of dollars from the Covid stimulus package – the 2021 American Rescue Plan – and the Inflation Reduction Act.

There’s a long way to go and limited funds. According to American Forests, more than 800,000 more trees are needed to achieve 15% canopy cover for every residential block in the city.

The slow progress in improving tree coverage has frustrated many Phoenix residents, and in May, the heat team will present a new master shade plan to the city council, setting out more nuanced data-driven goals for homes, sidewalks and parks to replace the 25% citywide one. At the heart of the plan will be tackling shade inequalities that make rising temperatures increasingly deadly for the city’s most vulnerable communities, according to David Hondula, who leads the office of heat response and mitigation.

“The core concepts driving the masterplan are improving public health and livability by creating more shade in the places people spend most time,” said Hondula.

In Grant Park, the community celebrates every single tree but it will probably take years to create adequate shade to provide residents – including unsheltered neighbors and passersby – adequate protection from the worsening heat.

“We’ve always had to fight for everything here, we’re neglected but I love my neighborhood,” said Evangeline Muller, 75, who loads up her golf buggy with buckets to water the trees when it gets really hot. “Trees mean health, they give life, and I’m not going to stop fighting for my community.”

Average incomes will fall by almost a fifth within the next 26 years as a result of the climate crisis, according to a study that predicts the costs of damage will be six times higher than the price of limiting global heating to 2C.

Rising temperatures, heavier rainfall and more frequent and intense extreme weather are projected to cause $38tn (£30tn) of destruction each year by mid-century, according to the research, which is the most comprehensive analysis of its type ever undertaken, and whose findings are published in the journal Nature.

The hefty toll – which is far higher than previous estimates – is already locked into the world economy over the coming decades as a result of the enormous emissions that have been pumped into the atmosphere through the burning of gas, oil, coal and trees.

This will inflict crippling losses on almost every country, with a disproportionately severe impact on those least responsible for climate disruption, further worsening inequality.

The paper says the permanent average loss of income worldwide will be 19% by 2049. In the United States and Europe the reduction will be about 11%, while in Africa and south Asia it will be 22%, with some individual countries much higher than this.

“It’s devastating,” said Leonie Wenz, a scientist at the Potsdam Institute for Climate Impact Research and one of the authors of the study. “I am used to my work not having a nice societal outcome, but I was surprised by how big the damages were. The inequality dimension was really shocking.”

The study also looked at the second half of this century, where human actions now can still make a big difference. If business as usual continues, the authors projected average income losses of more than 60% by 2100. But if emissions fall to net zero by mid century, income declines will stabilise by mid century at about 20%.

The economic hit predicted by the paper is more than twice as high as any previous analysis.

Behind that difference is a more sophisticated methodology. While most previous studies considered only damages related to rising temperatures at a national level, the new paper also incorporated rainfall and extreme weather impacts using 40 years of data from 1,600 subnational regions. This is important because weather is a local rather than national phenomenon. The study also considered how impacts tend to persist over months and years, rather than being only a short-term hit.

Previous projections were optimistic that most northern hemisphere economies would continue to grow. By contrast, the new paper says countries such as Germany (-11%), France (-13%), the US (-11%) and UK (-7%) will lose out even by mid century. Worst affected will be countries in already hot regions including Botswana (-25%), Mali (-25%), Iraq (-30%), Qatar (-31%), Pakistan (-26%) and Brazil (-21%).

Maximilian Kotz, an author of the study, said: “Strong income reductions are projected for the majority of regions, including North America and Europe, with south Asia and Africa being most strongly affected. These are caused by the impact of climate change on various aspects that are relevant for economic growth such as agricultural yields, labour productivity or infrastructure.”

Although the newly painted scenario is far worse than anything that came before, the authors acknowledge it is still conservative and incomplete. There are many major climate impacts that have not yet been incorporated into the analysis, including heatwaves, sea level rise, tropical cyclones, tipping points, and damage to natural ecosystems and human health. The authors said these factors would be added to future models.

“We are providing a more comprehensive picture but this is not the final picture,” Wenz said. “It is likely a lower bound.”

The authors said the study showed the need for stronger adaptation strategies, particularly in poorer, worst-affected countries, to cope with the changes up to 2050 that are already locked into the climate system.

It also found that reducing emissions was far cheaper than doing nothing and accepting more severe impacts. By 2050, it calculated mitigation costs – for example, from phasing out fossils and replacing them with renewable energy – to be $6tn dollars, which is less than a sixth of the median damage costs for that year of $38tn.

Anders Levermann, the head of complexity science at the Potsdam Institute, said: “It is on us to decide: structural change towards a renewable energy system is needed for our security and will save us money. Staying on the path we are currently on will lead to catastrophic consequences. The temperature of the planet can only be stabilised if we stop burning oil, gas and coal.”