One of the thorniest problems of the 21st century is how to get people to eat less meat. A new poll conducted by The Associated Press-NORC Center for Public Affairs Research found that most U.S. adults said they eat meat at least several times a week. About two-thirds said they eat chicken or turkey that often, and 43% eat beef that frequently. Experts agree that the urgency of climate change and the demands of a surging global population call for an overhaul of how humans get their protein. That will require changing consumer behavior. One answer? Small nudges to eat less meat.

Pastoralists in Senegal and Mongolia draw on millennia of experience to raise livestock in harsh, volatile climates. But they and other pastoralists around the world face mounting pressures from deteriorating environments, shrinking rangelands, and new generations who seek a less grueling and tenuous life. At the same time, pastoralism is modernizing, with groups leveraging new technology to better care for their animals. In fact, the practice has survived for so long because it is designed to adapt to changing environments. Experts say it provides lessons that could help those who raise livestock at much larger scales adapt to climate change.

More than 150 startups around the globe are chasing the same ambitious goal: meat conjured from animal cells that doesn’t require raising and killing animals. The aim is to make it affordable and taste and feel like the meat we eat now. The ultimate goal? To use cell biology to reduce the environmental impact of the world’s ever-increasing demand for meat and change global protein production the way electric cars are shaking up the auto industry. Companies making so-called “cultivated” meat are trying to scale up quickly. But they face scientific hurdles and public perception issues, and wide adoption is nowhere near assured.

Aquaculture has been the fastest growing food sector in the world for decades, and people now eat more farmed fish than wild fish. Fish farming and shellfish production usually spew far less greenhouse gas emissions than production of beef and other animal protein, but aquaculture can still cause serious environmental problems. Many are like problems that face massive chicken, pig and cattle operations. Faced with stinging criticism and tighter regulations — and eager to meet demand — fish farmers are trying new ways to boost production and minimize harm.

Climate scientists have long said that eating more plants and fewer animals is among the simplest, cheapest and most readily available ways for people to reduce their impact on the environment. And an explosion of new types of plant-based “meat” made from made from soybeans and other plants has emerged as a possible solution. But even though the products have come a long way from the dry veggie patties of the past, they haven’t converted enough meat lovers to make enough of an impact. New techniques are in development, however, with hopes of satisfying our enduring craving for flesh with plants.

Saving the remaining Amazon rainforest in Brazil will require ensuring that the 28 million people who live there can sustainably make a living. An AP analysis of data derived from satellite images showed that a vast area of the Amazon — larger than the size of Portugal — has been cleared for agriculture, then abandoned because of poor soil quality. Simple low-cost farming practices, such as planting legumes to enrich soil with nitrogen, can help farmers get more out of already cleared areas. And developing sustainable supply chains for rainforest fruits can help people derive money from standing forest.

For generations, beef has been the most quintessential of American main courses, and a premium protein around the world. It’s also the single most damaging food for the planet. Beef is the largest agricultural source of greenhouse gasses worldwide, and it has a bigger carbon footprint than any other type of protein. Climate scientists say the answer is simple: Eat less beef and raise fewer cattle. But most people are consuming more beef, not less. Researchers and ranchers are looking for solutions. Among them is regenerative ranching. It’s a practice in which cows are moved frequently to different pastures in an effort to restore the soil.