The UN says that we have to completely transform how we use land and grow food

To tackle climate change, we’ll need to do more than eliminate emissions from power plants and cars. Humans now sprawl over more than 70% of the planet’s land surface (not counting the places that are still covered in ice). And what we do with land now—from how we grow crops to whether we keep forests standing—will determine whether we can avoid the worst impacts of climate change and what will happen to the food supply, says a new report from the UN’s Intergovernmental Panel on Climate Change.

“This report really underscores the importance and urgency of lands,” says Will Turner, senior vice president of global strategies at the nonprofit Conservation International. “What we do to protect and to restore land this generation will affect whether our children, and those they share the planet with, are going to suffer. . . . We can stop fossil fuel emissions tomorrow and still fail if the Amazon is cleared or Sumatra burns.”

Some solutions are especially important. Protecting ecosystems that are already rich in carbon, like mangrove forests, rainforests, and peatlands, a type of carbon-filled wetland, is one key step. Unfortunately, many places are moving in the wrong direction: Deforestation in Brazil has surged 278% in the last year. Planting and restoring forests, as long as it happens in the right places and doesn’t interfere with food production, can sequester CO2 without waiting for the startups that are building the first carbon-sucking machines to scale up their technology. “Restoration of forests is the only technology that we have for absorbing CO2 that’s already in the atmosphere at scale,” says Turner.

Up to a quarter of food is wasted, and cutting food waste will cut emissions. Eating more plants and less red meat will help. Changing soil management, so crops are grown in a way that allows the soil to help absorb more carbon from the atmosphere, will also help. Finding ways to grow more food without cutting down forests is another key—the food sector is responsible for 75% of global deforestation.

The food system will also be hit particularly hard if climate change isn’t addressed. Farmers are already seeing a reduction in yield as climate change drives heat waves, droughts, and flooding, the report says. That can help drive food prices higher. As climate change progresses, yields will drop more, and some food may become less nutritious.

The world needs to act quickly to avoid that bleak future. “We’re making some progress on managing lands and climate change generally, but we’re making incremental progress against an exponential problem,” says Turner. Governments can take the new report and use it as a guide for planning new policy, but businesses also play a key role—particularly food businesses and any companies that use materials from forests.

Some companies are beginning to make some progress on reducing deforestation, Turner says, as technology makes it easier to track what’s happening in supply chains. He argues that they need to go further than just not buying from suppliers that cause deforestation, since if one brand leaves, another might take its place. “There needs to be a proactive approach: How can I actually be a part of improving the practices in these landscapes so that the forests stay there? How can I be a part of actually promoting restoration in these places?” he says. “When you start talking about not just protecting but restoring, you get out of the dynamic of ‘Let’s do less bad,’ and you get into ‘Let’s do more good.'”