This is what the 2022 Earthshot finalists are doing to tackle climate change

Human ingenuity is going to be a vital component to reaching net-zero emissions, and the Earthshot Prize — now in its second year — is highlighting the work of 15 finalists who are offering solutions to some of the biggest problems on the planet.

The five winners - who will receive £1 million ($1.2m) of prize money, as well as access to a global network of support to scale up their environmental solutions - will be announced in Boston, US, on 2 December.

Here are the finalists — split into the five Earthshot categories pictured below — and this is what they’re doing to tackle climate change.

Global food security is dependent on fertile land, but climate change is turning more land into unusable desert. The Desert Agricultural Transformation programme in China is hoping to reverse the desertification process by using a technique called ‘soilization’. A water-based paste is mixed with sand, which gives it similar properties to soil, allowing plants to grow. As crops grow and roots decay, the ‘soilized’ sand becomes self-sustaining.

In Malaysian Borneo, human activities have led to the breaking up of the Kinabatangan forest into multiple smaller areas, which has effectively trapped wildlife in isolated pockets.

Hutan is a wildlife research, education and conservation organization — their research revealed that the wildlife could survive in future if allowed to travel freely through specially made corridors, mitigating the impact of the massive deforestation.

In India, Kheyti, designers of the ‘greenhouse-in-a-box’, have already seen the results of their innovative greenhouse. Plants require 90% less water than those outdoors and use fewer pesticides too, while yields are reported to be seven times higher.

In Africa, 700 million people use cookstoves that burn firewood or charcoal, which are harmful both to humans and the environment. Rather than burning solid fuels, Charlot Magayi has created Mukuru Clean Stoves, which use processed biomass made from charcoal, wood and sugarcane, reducing pollution by 70% compared with a traditional cookstove. They also cost less to buy than traditional cookstoves and less to use.

A 2017 research project at Sweden’s Linköping University has led to Roam, an electric motorbike and bus company designed for the African market. The aim is to make electric transport more accessible to a broader market, by keeping costs low, and reliability high. Roam estimates that drivers can cut costs by 75%, as well as reduce emissions by replacing the ubiquitous and polluting motorcycle taxis that dominate parts of East Africa.

Construction sites often use noisy and polluting power derived from fossil fuel engines as a source of electricity. But AMPD Energy – which features on the World Economic Forum’s Uplink open innovation platform that connects investors and experts with entrepreneurs – have devised an alternative. The Enertainer is an electric battery energy storage system designed for construction sites that eliminates harmful pollution. It can power any type of electrical equipment with its lithium-ion batteries, and can reduce running costs by 85%, as well as make construction sites safer and quieter for workers and surrounding communities.

The city of Amsterdam is the first city to commit to becoming a circular economy — whereby people re-use materials to avoid waste.

In a circular economy, the value of raw materials is retained for as long as possible, by re-using and recycling again and again. The initiative should cut emissions, create jobs and foster an environment of “solidarity between the people,” according to the city of Amsterdam.

India throws over 1,000 tonnes of flowers into the river Ganges every day; because they are used for rituals, they are considered sacred, so cannot be thrown into the trash. Many contain toxic chemicals from pesticides and insecticides, contributing to the river Ganges being one of the most polluted in the world.

Phool collects floral waste so that it does not go into the Ganges. Currently, Phool uses the floral waste to create incense sticks. But in the process of making incense, a mat-like substance began to form over the unused fibres on the factory floor, which has the potential to be an alternative to leather. This bio-leather, known as Fleather, could become an alternative to animal leathers.

Just 9% of all the plastic ever produced has been recycled. The rest is incinerated, or lies in landfill, or is dumped into the sea. UK-based company Notpla has launched an alternative to plastic that is derived from seaweed, and has an array of uses, from a bubble to hold liquids, to food containers and even paper. Seaweed — which grows up to a metre a day — does not require fresh water or fertilizer, and is carbon negative.

The Queensland Indigenous Womens Ranger Network was established in 2018 to provide a forum for women rangers to share experiences, ideas and information. The rangers are using their knowledge to repair fragile ecosystems, from bushfires to the destruction of the Great Barrier Reef, and the project could be a template for other indigenous communities around the world.

Over 8 million tonnes of plastic end up in the world’s oceans every year, and it is difficult to remove. The Great Bubble Barrier offers a new way to stop plastic from reaching the ocean. Air is pumped through a perforated tube placed on riverbeds, and the bubbles push up plastic to the surface into a collection system, without getting in the way of boats or wildlife. The initiative is already being used in the Netherlands, and catches around 86% of plastic waste.

SeaForester is a Portugal-based company that offers mobile seaweed nurseries to coastal communities across the world. Half the world’s kelp forests have gone in the past 50 years. By taking seaweed spores and seeding them onto stones that are dropped into the ocean, seaweed forests can gradually return, providing an environment for marine life to thrive, while absorbing CO2.

Capturing CO2 is a vital part of reaching net-zero emissions. While carbon capture storage requires long-term monitoring, Oman-based project 44.01 is using a natural process to ‘mineralize’ CO2 in peridotite, a type of rock found across several continents.

Peridotite mineralization occurs naturally over time, but 44.01 accelerates the process by pumping carbonated water into deep underground seams, turning CO2 into a solid mineral that cannot escape.

US firm LanzaTech uses gas fermentation technology to trap pollution and turn it into something useful, such as sustainable fuels, packaging, cosmetics and textiles.

Instead of using fossil fuels from the ground, LanzaTech transforms CO2 and agricultural, industrial and municipal waste to make products. Companies are already using the technology, and have diverted 190,000 tonnes of CO2 emissions into products so far.

UK-based Low Carbon Materials (LCM) is focused on reducing emissions from the highly polluting cement industry. Demand for cement continues to rise, and LCM has devised a carbon-negative alternative — called OSTO — to one of the main ingredients of concrete.

OSTO is made from waste materials and by-products, and as well as being carbon negative, is lighter and thermally insulating too.