Background science

This website allows you to explore how different scenarios of global greenhouse gas emissions and adaptation to climate change could change the geography of food insecurity in developing and least-developed countries. The website maps an index of vulnerability to food insecurity at national level. This is calculated based on exposure to climate-related hazards, sensitivity of agricultural production to those hazards, and the capacity of countries to cope with climate-related food shocks. By altering the levels of future global greenhouse gas emissions and/or the levels of adaptation, you can see how vulnerability to food insecurity changes over time, and compare and contrast these different future scenarios with each other and the present day.

Vulnerability to food insecurity in the present-day

The climate and food insecurity index shown on this website is a measure of vulnerability of the food system to climate-related hazards.

Vulnerability is calculated at a country level and is comprised of three components:

Exposure to climate-related hazards,

to climate-related hazards, Sensitivity of national agricultural production to climate-related hazards,

of national agricultural production to climate-related hazards, Adaptive capacity a measure of capacity to cope with climate-related food shocks.

Exposure

The exposure component of the index is calculated from a measure of the average length of flood and drought events in each country. This is constructed from gridded meteorological data for the baseline period (1981-2010). The exposure is only calculated over areas with a population density greater than 150 people per km2 and/or more than 1% of the area given over to crop production.

Sensitivity

The sensitivity component of the index is calculated using indicators relevant to agricultural production. These are measures of the amount of forest cover, rainfed agriculture and cereal crop yield per country.

Adaptive capacity

The adaptive capacity component of the index is calculated using socio-economic indicators relevant to the food security system. These are measures of rural and urban populations with access to water resources, the percentage of rural population, population growth rate, population below the poverty line ($2 per day), vulnerable employment, government effectiveness and the number of paved roads per country.

Criteria for inclusion

All data included in the vulnerability to food insecurity index correlates with the Food and Agriculture Organisation (FAO) measure of undernutrition. Vulnerability to food insecurity as a result of weather events is most apparent in developing and least-developed countries, as they rely more heavily on in-country food production compared to the most developed countries which have access to markets. For this reason, OECD and EU countries are not included in the calculation. Small countries (< 500 km2) and those with few people and/or little or no agricultural production are also not included in the calculation.

Future projections of vulnerability to food insecurity

Future projections of the climate and food insecurity index have been calculated for a range of scenarios of different future global greenhouse gas emissions and adaptation levels.

Greenhouse gas emission scenarios

There are three scenarios of future global greenhouse gas emissions to choose from: low, intermediate or high emissions. These three scenarios correspond to climate model projections of the climate system response to three different greenhouse gas concentration pathways:

The low emissions scenario represents a rapid and sustained reduction in future global greenhouse gas emissions resulting in an increase in global average temperature of around 2°C above pre-industrial levels by the end of the 21st century. This scenario is also known as RCP2.6.

The intermediate emissions scenario represents a modest reduction in future global greenhouse gas emissions resulting in an increase in global average temperature of around 2.5°C - 3°C above pre-industrial levels by the end of the 21st century. This scenario is also known as RCP4.5.

The high emissions scenario represents considerable future increases in global greenhouse gas emissions resulting in a rise in global average temperature of 4°C or more above pre-industrial levels by the end of the 21st century. This scenario is also known as RCP8.5.

The climate model projections are used to calculate future projections of the exposure component of the index. Twelve climate models from the latest generation of climate models used to inform the most recent Inter-Governmental Panel on Climate Change report (IPCC AR5) were used, and the average value of the index for each country across the models is shown.

Information about the model spread of the results

Scenarios of adaptation investment

There are three scenarios of different adaptation levels to choose from: high, low or no adaptation. The scenarios determine how sensitive agricultural production is to climate-related hazards and the capacity to cope with climate-related food shocks in the future. Applying an adaptation scenario changes the sensitivity and adaptive capacity components of the index.

The level of change follows standardised scenarios and the change was scaled to allow the most vulnerable countries to improve most relative to the present-day, and the least vulnerable countries to change the least:

The ‘high’ adaptation scenario corresponds to a change of approximately 10-15% in the 2050s compared to the present-day, and a further change of approximately 10-15% in the 2080s compared to the 2050s.

The ‘low’ adaptation scenario corresponds to a change of approximately 5-10% in the 2050s compared to the present-day, and a further change of approximately 5-10% in the 2080s compared to the 2050s.

The no adaptation scenario maintains the sensitivity and adaptive capacity components of the index at the present-day level.

Technical detail about the methodology