A trophic level of an organism is its position in a food chain. Levels are numbered according to how far particular organisms are along the chain from the primary producers, to herbivores, to predators, to carnivores or top carnivores.

Over the past 40 years, globally, intensification of cultivated systems has been the primary source (almost 80%) of increased output. But some countries, predominantly found in sub-Saharan Africa, have had persistently low levels of productivity, and continue to rely on expansion of cultivated area.

The years 1960–2000 have shown a rapid move toward flow stabilization, which has slowed recently in some parts of the world due to the growing social, economic, and environmental concerns surrounding large hydraulic engineering works.

Timber is harvested from forests and plantations and used for a variety of building, manufacturing, fuel, and other needs. Forests (providing fuelwood and charcoal), agricultural crops, and manure all serve as sources of biomass energy.

Access to improved drinking water is estimated by the percentage of the population using the following drinking water sources: household connection, public standpipe, borehole, protected dug well, protected spring, or rainwater collection.

The cell color indicates impact of each driver on biodiversity in each type of ecosystem over the past 50–100 years. High impact means that over the last century the particular driver has significantly altered biodiversity in that biome; low impact indicates that it has had little influence on biodiversity in the biome. The arrows indicate the trend in the driver. Horizontal arrows indicate a continuation of the current level of impact; diagonal ...

Order from Strength, which focuses on reactive policies in a regionalized world, has the least favorable outcomes for human well-being, as the global distribution of ecosystem services and human resources that underpin human well-being are increasingly skewed. Wealthy populations generally meet most material needs but experience psychological unease.

Access to improved sanitation is estimated by the percentage of the population using the following sanitation facilities: connection to a public sewer, connection to a septic system, pour-flush latrine, simple pit latrine (a portion of pit latrines are also considered unimproved sanitation), and ventilated improved pit latrine.

In most countries, the marketed values of ecosystems associated with timber and fuelwood production are less than one third of the total economic value, including non-marketed values such as carbon sequestration, watershed protection, and recreation.

In the case of forest cover change, the studies refer to the period 1980–2000 and are based on national statistics, remote sensing, and, to a limited degree, expert opinion. In the case of land cover change resulting from degradation in drylands (desertification), the period is unspecified but inferred to be within the last half-century, and the major study was entirely based on expert opinion, with associated low certainty. Change in cultivated ...

Atmospheric deposition currently accounts for roughly 12% of the reactive nitrogen entering terrestrial and coastal marine ecosystems globally, although in some regions, atmospheric deposition accounts for a higher percentage (about 33% in the United States). (Note: the projection was included in the original study and is not based on MA scenarios.)

100% degradation means that all the services in the category were degraded in 2050 compared with 2000, while 50% improvement could mean that three out of six services were enhanced and the rest were unchanged or that four out of six were enhanced and one was degraded. The total number of services evaluated for each category was six provisioning services, nine regulating services, and five cultural services.

The time scale of change refers to the time required for the effects of a perturbation of a process to be expressed. Inertia refers to the delay or slowness in the response of a system to factors altering their rate of change, including continuation of change in the system after the cause of that change has been removed.

There are major distributional impacts among countries and within countries that in many cases have not been favorable for small-scale farmers and rural livelihoods. The poorest developing countries are net losers under most trade liberalization scenarios.

In SSA women make up two-thirds of those infected with HIV/AIDS. This adds additional burdens for women as producers of food and as family caretakers. Labor loss due to illness, need to care for family members and paid employment required to cover medical costs may cause families to decrease their farming activities.

Overall, agriculture (cropping and livestock) contributes 13.5 % of global greenhouse gas emissions mostly through emissions of methane and nitrous oxide (about 47% and 58% of total anthropogenic emissions of CH4 and N2O, respectively). The largest producer is power generation at 25.9% followed by industry with 19.4%.

Food security is a situation that exists when all people, at all times, have physical, social and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life. Food sovereignty is defined as the right of peoples and sovereign states to democratically determine their own agricultural and food policies.

Modern biotechnology is a term adopted by international convention to refer to biotechnological techniques for the manipulation of genetic material and the fusion of cells beyond normal breeding barriers. The most obvious example is genetic engineering to create genetically modified/engineered organisms (GMOs/GEOs) through “transgenic technology” involving the insertion or deletion of genes.

Substantial gains in agricultural productivity over the past 50 years have reduced rates of hunger and malnutrition, improved the health and livelihoods of many millions of people and stimulated economic growth in numerous countries. World cereal production has more than doubled since 1961 with average yields per hectare increasing around 150% in many high and low income countries, with the exception of most nations in sub-Saharan Africa.

There is a need to develop agricultural policies that both reduce emissions and allow adaptation to climate change that are closer to carbon-neutral, minimize trace gas emissions and reduce natural capital degradation. Important questions include how emissions from agriculture and forestry can be effectively reduced, how to produce food with greater input efficiency, and less GHG emissions, how can agriculture, agroforestry and forestry best adap...