We’re not managing our crops to support global nutritional needs: In fact, we use a disproportionate amount of land used to grow grains, fats, oils, and sugar, and not enough land to grow the fruits and vegetables that we need to survive, a new research paper asserts.

Climate change has made it more more crucial than ever to produce food as efficiently as possible. Not only does climate change threaten the productivity of crops around the globe, but the agricultural sector is one of the biggest sources of greenhouse gases (second only to burning fossil fuels).

The researchers compared the ideal nutritional profile of a human diet with the land use and greenhouse gas emissions tied to making those foods. They found that to grow the nutrients we need for our diet, we would have to reduce the amount of land used for growing grains by 150 hectares, 105 million hectares for fats and oils, and 30 million hectares for sugars.

Meanwhile, the land given to grow fruits and vegetables would have to go up by 171 hectares. (For perspective, a hectare is 10,000 square meters.)

The researchers used the Harvard Healthy Eating Plate model as their basis of an ideal nutrition model. In doing so, they suggest that per person, we need to grow three more servings of fruits and vegetables, two more servings of protein, as well as six fewer servings of grains, and four fewer servings of sugar.

However, their recommendations don't define how big a serving is, according to the the Harvard Nutrition Source team in the Department of Nutrition, which devised the Healthy Eating Plate system. “They [the relative section sizes] are not based on specific calorie amounts, and they are not meant to prescribe a certain number of calories or servings per day, since individuals’ calorie and nutrient needs vary based on age, gender, body size, and level of activity,” the department said in an statement.

Even so, the general narrative that we need to drastically change our food production holds up. As the world population has grown, so has the amount of greenhouse gases emitted while producing the agriculture necessary to feed everyone. From 1993 to 2013, greenhouse gas emissions due to agriculture ballooned by over a gigaton.

The paper points out that we produce enough food on an annual basis to meet the caloric needs (not nutritional needs) of every person on food. Rather, the problem we have is often poor agricultural management.

One solution is to eat less meat, says a new report by the Intergovernmental Panel on Climate Change (IPCC), a group of climate scientists working for the United Nations. But while that would obviously help us lower emissions, the researchers admit, isn’t realistic. “A complete shift to a vegetarian diet where protein comes from leguminous crops, global agriculture would need 80 million [hectacre] more arable land and 360 million [hectacre] less pasture land to feed the world’s 2050 population,” the study reads.

Since everyone giving up meat is off the table, the researchers mentioned a variety of different problem-solving approaches to make up the difference. For instance, we could improving the efficiency of livestock production by breeding animals that produce fewer greenhouse gases (cows release an inordinate amount of methane through their farts, and methane is a greenhouse gas more dangerous to the atmosphere than carbon, or restricting grazing to a smaller area of land for a shorter period of time.

The researchers also recommended increasing our reliance on alternative proteins such as fungi, algae, or insects, as well as increasing fish consumption (which comes with its own set of environmental problems, but is better in terms of greenhouse gas emissions).

The paper takes into account scientific and technological innovation, such as genetically modified organisms, that has helped us grow enough food for the global population today. The researchers assume that we’ll come up with a new technological way to increase fruit and vegetable yields 1 percent over the next 50 years—which is still a long way off from the 8 percent they suggest in order to adapt to population growth while all following a Harvard Healthy Eating Plate-appropriate diet.

“In reality, yield increases are likely to be more variable due to factors such as climate change and other unforeseen changes to the agricultural system,” the paper states. Natural disasters such as typhoons and hurricanes, for instance, which are more likely due to climate change, can have devastating effects on crop yields. This year, farmers in Florida and Georgia have lost an estimated $4 billion worth of food due to damage from Hurricane Michael.

Other experts have also argued that we should label foods in terms of their climate impact so that consumers understand the impact of their food choices.