The U.N. climate conference, to be held in Paris in December, represents the culmination of decades of complex climate negotiations that began in 1992. The COP21, as the conference is known, may well be the endgame — our last, best chance to achieve a global, legally binding climate agreement.

We desperately need one in order to curb fossil fuel emissions, put a price on carbon, and drive investments in climate-smart practices and technologies. But a Paris treaty must take a much bolder approach than simply reducing fossil fuel emissions. In most of the world — nearly 60 developing countries — deforestation and agriculture generate far more greenhouse gas emissions than the burning of fossil fuels.

How land is used — agriculture, forestry and other land-altering activities like suburban sprawl and mining — is therefore a key piece of the climate puzzle. Land use accounts for nearly a quarter of global GHG emissions, including approximately 10 percent from clearing forests for crops and grazing and another 10 – 12 percent from conventional methods of tilling the soil, raising livestock, applying chemical fertilizers and burning fields. These emissions could be greatly reduced through more sustainable practices.

Our decisions regarding land use have lasting and profound consequences. Reckless development can lead to major carbon emissions, while smart conservation strategies create important opportunities to fight global warming. Healthy forests and ecosystems actually pull carbon out of the atmosphere and store it in trees, plants and soil. Forests have the potential to capture and store 10–14 percent of gross carbon emissions from the atmosphere, while the land sector as a whole could sequester more than 25 percent.

At this juncture, the world needs developing countries with intact tropical forests to make a huge, positive contribution to fighting climate change by conserving their workhorse ecosystems. This despite the fact that developed countries like the United States are among the world’s biggest polluters, past and present; for example, the average per capita carbon emissions in Latin America are about one-seventh of U.S. per capita emissions.

Yet while tropical forests in the global South store the most carbon and harbor the most biodiversity in the world, they’re also under the greatest pressure to be cleared for timber and agriculture to meet the rising demands of our growing global population. And these regions tend to suffer the most from the impacts of global warming, such as climate-related diseases and extreme weather.