Removal of atmospheric carbon dioxide (CO2) combined with emission reduction is necessary to keep climate warming below the internationally agreed upon 2°C target. Soil organic carbon sequestration through agricultural management has been proposed as a means to lower atmospheric CO2 concentration, but the magnitude needed to meaningfully lower temperature is unknown. The authors show that sequestration of 0.68 Pg C year−1 for 85 years could lower global temperature by 0.1°C in 2100 when combined with a low emission trajectory [Representative Concentration Pathway (RCP) 2.6].

The UNCCD is unique as the only global policy body focused on combating desertification, land degradation and drought, which I will call “DLDD” from now on. The UNCCD recognizes the need to improve the scientific basis supporting its work. It has given us the responsibility of re-invigorating that scientific process.
A successful conference will go a long way towards the renewal of the UNCCD, as called for in the UNCCD’s
10-Year Strategy.

In the last ten years or so, the global interest in, and concerns about, the issue of how the world shall provide a growing population with sufficient food, bioenergy and wood raw material has attracted increasing attention. Will land and water resources be enough, how shall they be best managed to achieve increased production and productivity without causing far-reaching negative environmental and social side-effects, will climate change make solutions more difficult, will there be financial means and know-how available to address all challenges and opportunities?

Global food security and agricultural land management represent two urgent and intimately related challenges that humans must face. The authors quantify the changes in the global agricultural land footprint if the world were to adhere to the dietary guidelines put forth by the United States Department of Agriculture (USDA), while accounting for the land use change incurred by import/export required to meet those guidelines. The authors analyze data at country, continental, and global levels.

Agriculture influences and shapes the world’s ecosystems, but not always in a positive way. More than 2.5 billion people are globally involved as stewards of land and water ecosystems that constitute the natural resource base for feeding the current and future world population. Yet, conventional agronomic interventions based on ‘hard’ agricultural engineering compromise various eco-services that are required for sustainable agricultural development.

Land degradation and desertification reduce the provision of ecosystem services by lands and soils. This constrains development, reduces water, food, and energy security, and triggers resource conflicts. Although biophysical processes and economic impacts are increasingly understood, efforts to combat degradation have been failing thus far to prevent further losses of land productivity, a cost estimated at 42 billion USD/year (Dregne & Chou, 1992; Requier-Desjardins, 2007).

Human activity and related land use change are the primary cause of accelerated soil erosion, which has substantial implications for nutrient and carbon cycling, land productivity and in turn, worldwide socio-economic conditions. Here the authors present an unprecedentedly high resolution (250 × 250 m) global potential soil erosion model, using a combination of remote sensing, GIS modelling and census data. The authors challenge the previous annual soil erosion reference values as our estimate, of 35.9 Pg yr−1 of soil eroded in 2012, is at least two times lower.

Change in land management practices and governmental policies is urgently needed to reverse the continuing decline of marginal drylands. Marginal drylands are fragile ecosystems that sustain the livelihoods of millions of poor people in developing countries. However, their capacity to provide these services is continuously declining due to desertification, resulting in dwindling land productivity, and affecting human well-being and development opportunities in many marginal drylands.

The land use sector represents almost 25% of total global emissions. These emissions can be reduced. There is also great potential for carbon sequestration through the scaling up, and scaling out, of proven and effective practices. Improved land use and management, such as low-emissions agriculture, agro-forestry and ecosystem conservation and restoration could, under certain circumstances, further reduce the remaining emissions gap by up to 25%. These climate-smart land management practices nearly always come with adaptation co-benefits.

Land degradation is becoming a serious environmental issue threatening fertile agricultural soils and other natural resources. There are many driving forces behind land degradation. The expansion of artificial surfaces due to various economic activities, such as housing, industry, and transport infrastructure, known as soil sealing, constitutes one of the most intensive forms of land degradation in urban regions. Measures to halt and reverse land degradation require both strong land-use management policies, as well as effective spatial planning mechanisms.

This UNCCD-SPI technical report provides well-established scientific evidence for understanding the strong linkages between land use and drought and how management of both is connected through water use. It introduces a new concept of Drought-smart land management (D-SLM) and organizes relevant approaches and practices in fourteen groups across four major classes of land use.

The UNEP foresight report contains a description of the 21 emerging environmental issues identified through the UNEP Foresight Process. The process resulted in a list of 21 emerging environmental issues tagged 21 Issues for the 21st Century covering the major themes of the global environment including food, land, freshwater, marine, biodiversity, climate change, energy, waste, and technology, as well important cross-cutting issues ranging from the need for better environmental governance, to the need for human behavioral change towards the environment.