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More than 50 nations are taking action to reduce plastic pollution, says the UN in the biggest report so far.

India will eliminate all single-use plastic in the country by 2022, with an immediate ban in urban Delhi.

The pledge from a nation of 1.3 billion people is the most ambitious of the global plans against plastic pollution.

The UN report also reveals that the Galapagos will ban single-use plastics, Sri Lanka will ban styrofoam and China is insisting on biodegradable bags.

But the authors warn that far more needs to be done to reduce the vast flow of plastic into rivers and oceans.

Media playback is unsupported on your device Media caption BBC Science Editor David Shukman explains how plastic moves around the oceans

Action against plastic waste has many drivers across the world. In the UK it has been stimulated by media coverage.

In many developing countries, plastic bags are causing floods by blocking drains, or they’re being eaten by cattle.

The report says policies to combat plastic waste have had mixed results. In Cameroon, plastic bags are banned and households are paid for every kilo of plastic waste they collect, but still plastic bags are being smuggled in.

In several countries, rules on plastic exist but are poorly enforced.

Media playback is unsupported on your device Media caption Plastic pollution is killing animals in the Arctic

The report presents an A-Z of 35 potential bio substitutes for plastic. It runs from Abaca hemp (from the inedible banana Musa textilis) to Zein (from a maize protein).

The list includes rabbit fur, sea grass and foam made with fungus. It mentions QMilch, a firm that create casein textile fibres from waste milk.

It also highlights Piñatex, a plastic alternative made from pineapple leaves.

Some policy-makers, though, are wary about hyping the potential of bio alternatives.

Early optimism by some environmentalists about biofuels backfired when rainforests were felled to grow palm oil to fuel cars.

Erik Solheim, head of UN Environment, said: "The assessment shows that action can be painless and profitable – with huge gains for people and the planet that help avert the costly downstream costs of pollution. Plastic isn’t the problem. It’s what we do with it.”

The report says levies and bans – where properly planned and enforced – have been among the most effective strategies to curb plastic waste.

But the authors also cite a fundamental need for broader cooperation from business, including obliging plastic producers to take responsibility and offering incentives to stimulate more recycling.

Media playback is unsupported on your device Media caption Five ways to break up with plastic

National actions include:

Botswana – retailers charged but no enforcement and controls "failed".

Eritrea – ban on plastic bags and dramatic decrease in drain blockage

Gambia – ban on plastic bags, but "reappearance after political impasse"

Morocco – bags banned – 421 tonnes of them seized in one year, virtually replaced by fabric

Bangladesh – ban on bags but lack of enforcement

China – was using three billion bags a year pre-2008. Now there is a ban on thin bags, use decreased 60-80% in supermarkets but not in markets.

Vietnam – bags are taxed but still widely used. Government considering increasing tax five times

Ireland – tax led to 90% fall in consumption

Kenya – cows ingested an average of 2.5 bags in their lifetimes. Now there's a total ban, and fines and a four-year jail term for making, importing or using them

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