GLASGOW - Nature took centre stage at the COP26 climate talks in Scotland on Saturday (Nov 6), with 45 nations signing up to a pledge to protect forests and other threatened ecosystems and reform the way food is grown.

This came as protests continued for a second day in Glasgow as part of a global mobilisation against what campaigners say is a lack of urgency to address global warming at the crunch United Nations summit, which Swedish activist Greta Thunberg has labelled a "failure".

Events were planned worldwide from Paris to Sydney, Nairobi to Seoul to demand immediate action for countries already affected by climate change.

The focus on nature is vital because it provides necessities such as clean air and water, as well as soils for crops. Forests, soils and oceans also soak up carbon dioxide (CO2), the main greenhouse gas.

Yet, ecosystems are already under pressure from climate change and damaging agricultural practices, such as deforestation to plant vast soya and corn crops, build oil palm plantations, as well as cattle ranches for beef.

Agriculture, forestry and other forms of land use produce about a quarter of the world's greenhouse gas emissions. Food waste is another large source.

On Saturday, countries from across the world set out pledges to transform agriculture and food systems through policy reforms, research and innovation to cut emissions and protect nature.

Backers include major economies led by the United States, Britain, Japan and Germany and developing nations such as India, Indonesia, Morocco, Vietnam, the Philippines, Ghana and Uruguay.

Britain launched a £500 million (S$911 million) package to help protect five million hectares of rainforests from deforestation.

A total value for all the pledges by the 45 nations was not given. But COP26 host Britain said the pledges would leverage more than US$4 billion (S$5.4 billion) of new public sector investment into agricultural innovation, including the development of climate-resilient crops and ways to improve soil health.

The focus on nature and agriculture has become urgent. Climate change - from heatwaves to severe droughts and fires - is taking an increasing toll on the natural world, compounding damage caused by agriculture, mining and urban expansion.

Halting and reversing the damage is regarded as a key tool in trying to limit global warming to 1.5 deg C above pre-industrial times, a key goal of the 2015 Paris climate agreement and a key focus of the COP26 talks.

The danger is that some ecosystems will become sources of CO2, instead of carbon sinks.

That is already starting to happen. The Brazilian Amazon - the largest portion of the Amazon rainforest - is emitting more CO2 than it captures, according to a study published in July 2021 in the journal Nature.

"To keep (the goal of) 1.5 deg C alive, we need action from every part of society, including an urgent transformation in the way we manage ecosystems and grow, produce and consume food on a global scale," British Environment Secretary George Eustice said. "We need to put people, nature and climate at the core of our food systems."

The world has already warmed 1.1 deg C on average, the World Meteorological Organisation says, and the last seven years have been the warmest seven years on record, according to Nasa.

Dr Yadvinder Malhi, professor of ecosystem science at the University of Oxford, said it was positive that nations were focused on the importance of protecting and restoring nature.

"It is not just about soaking up more carbon, but ensuring that the biosphere is intact and resilient and does not turn into a carbon source that would make it almost impossible to stabilise the climate in the near term."

One of the key next steps is for nations to enact policies to change their agricultural policies to become more sustainable, less polluting and to invest in crops that are more resilient to climate change.

For example, Brazil plans to scale its low-carbon farming programme to 72 million hectares, saving 1 billion tonnes of emissions by 2030. Germany plans to lower emissions from land use by 25 million tonnes by 2030, and Britain aims to engage 75 per cent of farmers in low-carbon practices by 2030.

Another key focus on Saturday is the important role of millions of indigenous people as nature's guardians.

Research shows that indigenous groups protect some of the world's most biodiverse tropical forests, from the Amazon, to Indonesia and to the Congo Basin.

However, these communities have legally recognised rights to only less than half of the total area they manage.

At the COP26 summit, indigenous people have been pressing nations for better rights recognition, protection of their forest homes and an ambitious climate deal.