CountrySamoa
RegionAsia-Pacific
GDP (PPP 2021 [$billions])1.68
GPC (GDP per capita [$/person])7686.25
POP (Population [millions])0.22
LDA (Land Area [sq. km])2780
Table of EPI results for Samoa
Indicator Rank EPI Score 10-Year Change Regional Rank Regional Average
Environmental Performance Index 97 39.29 6.13 9 36.84
Environmental Health 85 44.58 0.10 11 43.11
Air Quality 74 43.26 -0.04 10 37.95
Ambient PM2.5 DALY rate 23 68.06 -2.33 3 37.60
Household solid fuels DALY rate 141 10.63 1.72 17 35.99
Ozone Exposure DALY rate 86 43.36 6.63 13 50.51
NO2 Exposure DALY rate 67 62.92 -4.12 5 46.18
Carbon Monoxide Exposure 2 96.73 -3.27 2 58.26
Sulfur Dioxide Exposure 5 99.15 6.98 4 49.13
Volatile Organic Compound Exposure 1 100.00 0.00 1 35.34
Sanitation & Drinking Water 87 54.30 1.98 9 51.71
Unsafe sanitation DALY rate 72 62.25 2.50 9 54.21
Unsafe drinking water DALY rate 100 49.00 1.64 11 50.04
Heavy Metals 109 42.90 -1.78 12 49.24
Lead Exposure DALY rate 109 42.90 -1.78 12 49.24
Waste Management 131 26.60 17 52.24
Sustainably Managed Solid Waste 131 26.60 17 52.24
Ecosystem Vitality 166 25.23 -2.19 21 34.89
Biodiversity & Habitat 171 9.87 -3.01 23 29.76
Marine Habitat Protection 94 2.26 0.00 18 16.05
Marine KBA Protection 107 0.36 0.00 18 24.71
MPA Effectiveness 97 0.00 -100.00 17 43.16
Terrestrial Biome Protection 143 26.19 0.36 16 43.20
Terrestrial KPA Protection 158 14.73 0.22 18 37.14
Protected Area Repr. Index 168 10.68 0.23 19 17.66
Protected Area Conn. Index 159 3.98 0.14 20 15.46
Species Protection Index 164 8.53 18 37.79
Species Habitat Index 51.96
Red List Index 141 25.97 -5.07 16 38.39
Biodiversity Habitat Index 87 40.55 -0.37 13 47.44
Bioclim. Eco. Resilience 136 17.90 0.87 22 46.53
Fisheries 32 74.79 -8.63 8 60.09
Fish Catch Discarded 92 39.00 -41.56 15 59.84
Bottom Trawling, open ocean 1 100.00 0.00 1 67.09
Bottom Trawling, domestic 1 100.00 0.00 1 61.57
Regional Marine Trophic Index 30 60.14 7.01 6 49.57
Forests 20.29
Tree Cover Loss 19.24
Tree Cover Loss in KBAs 21.29
Grasslands 40.88
Grassland conversion 38.79
Grassland conversion in KBAs 43.42
Air Pollution 60 64.77 8.83 7 49.61
NOx emission trend 46 74.06 6.69 6 47.48
SO2 emission trend 82 55.47 10.95 9 51.74
Agriculture 109 46.87 -11.11 17 48.58
Sustainable Nitrogen Management Index 133 30.45 8.07 18 43.31
Phosphorus Surplus 71 63.54 -36.46 10 55.56
Relative Crop Yield 33.59
Pesticide Pollution Risk 29 77.78 0.00 3 53.06
Water Resources 72 43.81 11 44.41
Wastewater Treatment 72 43.81 11 44.41
Climate Change Policy Objective 30 55.99 23.65 2 34.53
Climate Change Mitigation 30 55.99 23.65 2 34.53
CO2 emission trend 78 46.61 8.31 10 34.43
CH4 emission trend 4 80.24 49.14 1 44.05
N2O emission trend 1 100.00 96.73 1 47.17
F-gas emission trend 23.77
Black Carbon emission trend 73 61.59 20.74 10 61.61
GHG emission trend, adj. per capita 11 54.70 20.41 2 28.84
GHG emission trend, adj. per GDP 35 55.20 22.99 3 34.54
Projected emissions 2050 32 57.66 57.66 2 21.54
Carbon flux from land use change 49.14
Environmental Performance Index 2026Country ProfileSamoa

Environmental Performance Index (EPI)

The 2026 EPI ranks 177 countries on 47 environmental indicators across 12 issue categories representing critical sustainability challenges in environmental public health, ecosystem vitality, and climate change.

Environmental Health (HLT)

The Environmental Health policy objective measures how well countries are protecting their populations from environmental health risks. It comprises 25% of the total EPI score and is made up of four issue categories: Air Quality, Sanitation & Drinking Water, Heavy Metals, and Waste Management.

Air Quality (AIR)

The Air Quality issue category measures the impacts of air pollution on human health in each country. It consists of seven indicators: ambient PM2.5 exposure, household solid fuels, ozone exposure, nitrogen oxides exposure, sulfur dioxide exposure, carbon monoxide exposure, and volatile organic compound exposure.

Ambient PM2.5 DALY rate (PMD)

This indicator measures the amount of deaths and disease resulting from exposure to ambient particulate matter less than 2.5 micrometers in size (PM2.5). Estimates from the Institute for Health Metrics and Evaluation's Global Burden of Disease study report the age-standardized disability-adjusted life-year lost per 100,000 persons (DALY rate). A score of 100 indicates the lowest observed DALY rates around the world, and a score of 0 indicates the highest.

Household solid fuels DALY rate (HFD)

This indicator measures the amount of deaths and disease resulting from exposure to household air pollution from solid fuels. Estimates from the Institute for Health Metrics and Evaluation's Global Burden of Disease study report the age-standardized disability-adjusted life-year lost per 100,000 persons (DALY rate). A score of 100 indicates the lowest observed DALY rates around the world, and a score of 0 indicates the highest.

Ozone Exposure DALY rate (OZD)

This indicator measures the amount of deaths and disease resulting from exposure to tropospheric ozone. Estimates from the Institute for Health Metrics and Evaluation's Global Burden of Disease study report the age-standardized disability-adjusted life-year lost per 100,000 persons (DALY rate). A score of 100 indicates the lowest observed DALY rates around the world, and a score of 0 indicates the highest.

NO2 Exposure DALY rate (NOD)

This indicator measures the amount of deaths and disease resulting from exposure to nitrogen dioxide (NO2). Estimates from the Institute for Health Metrics and Evaluation's Global Burden of Disease study report the age-standardized disability-adjusted life-year lost per 100,000 persons (DALY rate). A score of 100 indicates the lowest observed DALY rates around the world, and a score of 0 indicates the highest.

Carbon Monoxide Exposure (COE)

This indicator measures a country's ambient ground-level concentration of carbon monoxide (CO), weighted by population to better capture the exposure levels in geographic areas with a higher human population density. A score of 100 indicates a country has among the lowest exposure in the world, and a score of 0 indicates a country is among the highest. Data come from the Copernicus Atmosphere Monitoring Service.

Sulfur Dioxide Exposure (SOE)

This indicator measures a country's ambient ground-level concentration of sulfur dioxide (SO2), weighted by population to better capture the exposure levels in geographic areas with a higher human population density. A score of 100 indicates a country has among the lowest exposure in the world, and a score of 0 indicates a country is among the highest. Data come from the Copernicus Atmosphere Monitoring Service.

Volatile Organic Compound Exposure (VOE)

This indicator measures a country's ambient ground-level concentration of volatile organic compounds (VOC), weighted by population to better capture the exposure levels in geographic areas with a higher human population density. We estimate volatile organic compounds as the summed concentration of ethane, propane, formaldehyde, and isoprene. A score of 100 indicates a country has among the lowest exposure in the world, and a score of 0 indicates a country is among the highest. Data come from the Copernicus Atmosphere Monitoring Service.

Sanitation & Drinking Water (H2O)

The Sanitation & Drinking Water issue category measures how well countries protect human health from environmental risks on two indicators: unsafe drinking water and unsafe sanitation.

Unsafe sanitation DALY rate (USD)

This indicator measures the amount of deaths and disease resulting from exposure to unsafe sanitation. Estimates from the Institute for Health Metrics and Evaluation's Global Burden of Disease study report the age-standardized disability-adjusted life-year lost per 100,000 persons (DALY rate). A score of 100 indicates the lowest observed DALY rates around the world, and a score of 0 indicates the highest.

Unsafe drinking water DALY rate (UWD)

This indicator measures the amount of deaths and disease resulting from exposure to unsafe drinking water. Estimates from the Institute for Health Metrics and Evaluation's Global Burden of Disease study report the age-standardized disability-adjusted life-year lost per 100,000 persons (DALY rate). A score of 100 indicates the lowest observed DALY rates around the world, and a score of 0 indicates the highest.

Heavy Metals (HMT)

The Heavy Metals issue category measures the direct impacts of heavy metal pollution exposure on human health in each country. It is based on one indicator, lead exposure.

Lead Exposure DALY rate (PBD)

This indicator measures the amount of deaths and disease resulting from exposure to lead. Estimates from the Institute for Health Metrics and Evaluation's Global Burden of Disease study report the age-standardized disability-adjusted life-year lost per 100,000 persons (DALY rate). A score of 100 indicates the lowest observed DALY rates around the world, and a score of 0 indicates the highest.

Waste Management (WMG)

The Waste Management issue category recognizes the threats of solid waste to human and environmental health. It is based on one indicator, the proportion of solid waste that is sustainably managed.

Sustainably Managed Solid Waste (SMW)

Sustainably managed solid waste refers to the proportion of household and commercial waste generated in a country that is collected and treated in a manner that controls environmental risks. This metric counts waste as “controlled” if it is treated through recycling, composting, anaerobic digestion, incineration, or disposed of in a sanitary landfill. A score of 100 indicates a country manages 100% of its waste in a sustainable way, while a score of 0 indicates a country fails either to control any of its solid waste – or to collect and report data on the fate of its solid waste. Data for this indicator come from the World Bank's What a Waste 3.0 report.

Ecosystem Vitality (ECO)

The Ecosystem Vitality policy objective measures how well countries are preserving, protecting, and enhancing ecosystems and the services they provide. It comprises 45% of the total EPI score and is made up of seven issue categories: Biodiversity & Habitat, Forests, Grasslands, Fisheries, Air Pollution, Agriculture, and Water Resources.

Biodiversity & Habitat (BDH)

The Biodiversity and Habitat issue category assesses countries' actions toward retaining natural ecosystems and protecting the full range of biodiversity within their borders. It consists of 12 indicators: protection of marine key biodiversity areas, protection of important marine and coastal habitats, stringency of marine protection, the Protected Areas Representativeness Index, the Protected Areas Connectedness Index, the Species Habitat Index, the Species Protection Index, terrestrial biome protection, protection of terrestrial key biodiversity areas, the Red List Index, the Biodiversity Habitat Index, and the Bioclimatic Ecosystem Resilience Index.

Marine Habitat Protection (MHP)

This indicator measures the percentage of important marine and coastal habitats – coral reefs, cold-water corals, sea grasses, salt marshes, mangroves, knolls, and seamounts – within a country's maritime zone(s) that are covered by marine protected areas or Other Effective Area-Based Conservation Measures (OECMs).

NB: Landlocked countries are not scored on this indicator, nor are countries who do not have important marine and coastal habitats within their marine zone(s). Weight assigned to this indicator is reapportioned to other indicators within the Biodiversity & Habitat issue category.

Marine KBA Protection (MKP)

This indicator measures the percentage of areas designated as Key Biodiversity Areas (KBAs) within a country's maritime zone(s) that are covered by marine protected areas or Other Effective Area-Based Conservation Measures (OECMs).

  • Marine Protected Area data come from the World Database on Protected Areas.
  • Data on KBAs are compiled by BirdLife International in partnership with other major conservation organizations.

NB: Landlocked countries are not scored on this indicator. Weight assigned to this indicator is reapportioned to other indicators within the Biodiversity & Habitat issue category.

MPA Effectiveness (MPE)

This indicator estimates the stringency of marine protected areas (MPAs) by comparing total fishing effort intensity (fishing hours per km2) on a given year inside versus outside MPAs within a country's maritime zone(s). A score of 100 indicates that fishing efforts inside a country's MPAs is 1% or less than the fishing effort outside MPAs, and a score of 0 indicates that fishing effort inside MPAs is at least twice as intense as outside. Fishing effort data, from Global Fishing Watch, is based on satellite tracking of fishing boats.

NB: Landlocked countries are not scored on this indicator. Weight assigned to this indicator is reapportioned to other indicators within the Biodiversity & Habitat issue category.

Terrestrial Biome Protection (TBN)

The terrestrial world comprises 14 kinds of ecoregions, or biomes, though not every country has every biome. We measure the area of every biome in a country then calculate how much of those biome types lie within protected areas or Other Effective Area-Based Conservation Measures (OECMs). According to Target 3 of the Kunming-Montreal Global Biodiversity Framework, countries should be protecting at least 30% of each biome type – the threshold for scoring 100 on this indicator. We weight biome types by their prevalence within each country. Data for this indicator come from the World Database on Protected Areas.

Terrestrial KPA Protection (TKP)

This indicator is the percentage of Key Biodiversity Areas (KBA) within a country's territory that is covered by protected areas or Other Effective Area-Based Conservation Measures (OECMs). A score of 100 indicates complete KBA protection, while a score of 0 indicates no overlap between KBAs and protected areas.Terrestrial Protected Area data come from the World Database on Protected Areas. Data on KBAs are compiled by BirdLife International in partnership with other major conservation organizations.

Protected Area Repr. Index (PAR)

The Protected Areas Representativeness Index measures how well terrestrial protected areas and Other Effective Area-Based Conservation Measures (OECMs) represent the ecological diversity of a country. This metric is calculated by CSIRO using high-resolution remote sensing data and biological records of species' locations. A score of 100 indicates that a country's terrestrial protected areas approach the highest observed potential for representing ecosystem diversity, and a score of 0 indicates complete unrepresentativeness.

Protected Area Conn. Index (PAC)

The Protected Areas Connectedness Index measures how well the connections between terrestrial protected areas and Other Effective Area-Based Conservation Measures (OECMs) allow ecosystems to function across broad landscapes. This metric is calculated by CSIRO using high-resolution remote sensing data and biological records of species' locations. A score of 100 indicates that a country's terrestrial protected areas approach the highest observed potential for connectedness, and a score of 0 indicates no connectedness.

Species Protection Index (SPI)

The Species Protection Index (SPI) measures how well a country's terrestrial protected areas overlap with the ranges of its vertebrate, invertebrate, and plant species. Map of Life calculates this index using remote sensing data, global biodiversity informatics, and integrative models to map suitable habitat for over 30,000 terrestrial species at high resolutions. A score of 100 indicates full coverage of all species' ranges by a country's protected areas, and a score of 0 indicates no overlap.

Species Habitat Index (SHI)

The Species Habitat Index (SHI) measures the proportion of suitable habitats for a country's species that remain intact, relative to a baseline set in the year 2001. While the SHI can be calculated for single species, Map of Life aggregates these metrics into a single score, with each species weighted according to the proportion of their global range that is found within the country. This weighting scheme encourages countries to take special care to ensure the protection of rare or endemic species. The SHI serves as a proxy for potential population losses and the extinction risk to individual species. A score of 100 indicates that a country has experienced no habitat loss since the year 2001, and a score of 0 indicates the worst levels of habitat loss.

Note: Due to methodological limitations, counties less than 30,000 km2 in area are not scored on this indicator. Weight assigned to this indicator is reapportioned to other indicators within the Biodiversity & Habitat issue category.

Red List Index (RLI)

The Red List Index (RLI) tracks the overall extinction risk for species in a country, weighting species by the fraction of their range occurring within the country or region. A score of 100 indicates that none of the evaluated species in the country are threatened, while a score of 0 indicates a very high average extinction risk.

Biodiversity Habitat Index (BHI)

The Biodiversity Habitat Index (BHI) estimates the effects of habitat loss, degradation, and fragmentation on the expected retention of terrestrial biodiversity. CSIRO calculates the BHI from remote sensing data and other studies of ecological diversity. A score of 100 indicates that a country has experienced virtually no habitat loss or degradation, and a score of 0 indicates nearly complete habitat loss.

Bioclim. Eco. Resilience (BER)

The Bioclimatic Ecosystem Resilience Index (BERI) measures the capacity of natural ecosystems to retain species diversity in the face of climate change, as a function of ecosystem area, connectivity and integrity. This metric is calculated by CSIRO based on land use maps and species occurrence data. A score of 100 indicates world-leading performance on this metric, and a score of 0 indicates worst performance.

Fisheries (FSH)

The Fisheries issue category measures the health and sustainability of the world's fisheries. It is made up of four indicators: fish catch discarded, fish caught by bottom trawling and dredging (domestically and across the global ocean), and the marine trophic index.

Note: Landlocked countries are not scored on this issue category. Weight assigned to the Fisheries issue category is reapportioned to other issue categories within the Ecosystem Vitality policy objective.

Fish Catch Discarded (FCD)

The proportion of a country's total catch in the global ocean that is discarded instead of landed and used. This indicator serves as a proxy of bycatch and thus of untargeted and wasteful fishing practices. A score of 100 indicates that none of a country's catch is discarded, and a score of 0 indicates worst performance. Data come from Sea Around Us.

Note: Landlocked countries are not scored on this indicator. Weight assigned to the Fisheries issue category is reapportioned to other issue categories within the Ecosystem Vitality policy objective.

Bottom Trawling, open ocean (BTO)

The proportion of a country's total catch across the global ocean caught by bottom trawling and dredging. This indicator measures how much countries use bottom trawling, either in their own waters, those of other countries, or in the high seas. A score of 100 indicates that the country catches no sealife with bottom trawling, and a score of 0 indicates worst performance. Data come from Sea Around Us.

Note: Landlocked countries are not scored on this indicator. Weight assigned to the Fisheries issue category is reapportioned to other issue categories within the Ecosystem Vitality policy objective.

Bottom Trawling, domestic (BTZ)

The proportion of the total catch caught using bottom trawling and dredging. This metric counts all seafood caught within a country's maritime zone(s), regardless of the flag of the vessel doing the fishing – and so measures both whether countries are practicing trawling themselves or allow other countries to trawl within waters under their jurisdiction. A score of 100 indicates that no sealife are caught with bottom trawling inside a country's maritime zone(s), and a score of 0 indicates worst performance. Data come from Sea Around Us.

Note: Landlocked countries are not scored on this indicator. Weight assigned to the Fisheries issue category is reapportioned to other issue categories within the Ecosystem Vitality policy objective.

Regional Marine Trophic Index (RMS)

The Marine Trophic Index (MTI), computed by Sea Around Us, describes the degree to which a country is depleting species at higher trophic levels and “fishing down the food web.” The metric describes the average trophic level of a country's catch, while accounting for the expansion of fishing operations to additional geographic areas. Our indicator is based on the slope of a line fitted to MTI values over one decade. A score of 100 indicates that the mean trophic level increased 0.015 per year over the last decade, and 0 indicates it decreased 0.015 per year.

Note: Landlocked countries are not scored on this indicator. Weight assigned to the Fisheries issue category is reapportioned to other issue categories within the Ecosystem Vitality policy objective.

Forests (FOR)

The Forests issue category measures the five-year average loss of trees (at ≥30% canopy cover), across the entire country and within Key Biodiversity Areas (KBAs), as a proportion of tree cover in the baseline year of 2000. Data on tree cover come from Global Nature Watch.

Note: Countries with less than 2,000 hectares of tree cover in 2000 are not scored on these indicators. Weight assigned to this issue category is reapportioned to other issue categories within the Ecosystem Vitality policy objective.

Tree Cover Loss (TCL)

This indicator measures the five-year average loss of trees (at ≥30% canopy cover), across the entire country, as a proportion of tree cover in the baseline year of 2000. A score of 100 indicates no tree cover loss in the past five years, and a score of 0 indicates among the worst rates of tree cover loss in the world. Data on tree cover extent and loss come from Global Nature Watch.

Note: Countries with less than 2,000 hectares of tree cover in 2000 are not scored on this indicator. Weight assigned to the Forests issue category is reapportioned to other issue categories within the Ecosystem Vitality policy objective.

Tree Cover Loss in KBAs (KFL)

This indicator measures the five-year average loss of trees (at ≥30% canopy cover), within Key Biodiversity Areas (KBAs), as a proportion of tree cover in KBAs in the baseline year of 2000. A score of 100 indicates no tree cover loss within KBAs over the past five years, and a score of 0 indicates among the worst rates of tree cover loss in the world. Data on tree cover extent and loss come from Global Nature Watch.

Note: Countries with less than 2,000 hectares of tree cover in 2000 are not scored on this indicator. Weight assigned to the Forests issue category is reapportioned to other issue categories within the Ecosystem Vitality policy objective.

Grasslands (GRS)

The Grasslands issue category measures the five-year average permanent conversion of natural and semi-natural grasslands to other types of land cover, such as cropland or built-up areas, across the entire country and within Key Biodiversity Areas (KBAs), as a proportion of grassland extent in the baseline year of 2000. Data on grassland extent and conversion come from the Global Pasture Watch research consortium, led by Land & Carbon Lab.

Note: Countries with less than 50 hectares of grassland extent in 2000 are not scored on these indicators. Weight assigned to this issue category is reapportioned to other issue categories within the Ecosystem Vitality policy objective.

Grassland conversion (GEL)

This indicator measures the five-year average permanent conversion of natural and semi-natural grasslands to other types of land cover, such as cropland or built-up areas, across the entire country, as a proportion of grassland extent in the baseline year of 2000. A score of 100 indicates no grassland conversion over the past five years, and a score of 0 indicates among the worst rates of conversion in the world. Data on grassland extent and conversion come from the Global Pasture Watch research consortium, led by Land & Carbon Lab.

Note: Countries with less than 50 hectares of grassland extent in 2000 are not scored on these indicators. Weight assigned to this issue category is reapportioned to other issue categories within the Ecosystem Vitality policy objective.

Grassland conversion in KBAs (KGL)

This indicator measures the five-year average permanent conversion of natural and semi-natural grasslands to other types of land cover, such as cropland or built-up areas, within Key Biodiversity Areas (KBAs), as a proportion of grassland extent in KBAs in the baseline year of 2000. A score of 100 indicates no grassland conversion within KBAs over the past five years, and a score of 0 indicates among the worst rates of conversion. Data on grassland extent and conversion come from the Global Pasture Watch research consortium, led by Land & Carbon Lab.

Note: Countries with less than 50 hectares of grassland extent in 2000 are not scored on these indicators. Weight assigned to this issue category is reapportioned to other issue categories within the Ecosystem Vitality policy objective.

Air Pollution (APO)

The Air Pollution issue category measures countries' emissions of sulfur dioxide (SO2) and nitrogen oxides (NOX), precursors to acid rain and other environmental damage.

NOx emission trend (NXA)

We measure the average annual growth rate of nitrogen oxides (NOX) emissions over the years 2014 to 2023 and adjust for economic trends to isolate change due to policy effort rather than economic fluctuation. A score of 100 indicates a country is cutting emissions by at least 5% per year, and a score of 0 indicates that a country is increasing emissions by 5% per year or more. Data come from the Community Emissions Data System.

SO2 emission trend (SDA)

We measure the average annual growth rate of sulfur dioxide (SO2) emissions over the years 2014 to 2023 and adjust for economic trends to isolate change due to policy effort rather than economic fluctuation. A score of 100 indicates a country is cutting emissions by at least 8.4% per year, and a score of 0 indicates that a country is increasing emissions by 8.4% per year or more. Data come from the Community Emissions Data System.

Agriculture (AGR)

The Agriculture issue category measures efforts to produce food and other agricultural products while minimizing the threats of agriculture to the environment. It is based on four indicators: the Sustainable Nitrogen Management Index (SNMI), Relative Yield Index, pesticide pollution risk, and phosphorus surplus.

Sustainable Nitrogen Management Index (SNM)

The Sustainable Nitrogen Management Index (SNMI) seeks to balance efficient application of nitrogen fertilizer with maximum crop yields as a measure of the environmental performance of agricultural production. A score of 100 indicates that a country is optimizing both crop yields and fertilizer application, and a score of 0 indicates a country has among the worst performance on the SNMI. Data supporting this metric come from the FAOSTAT crop nutrient budget database.

Phosphorus Surplus (PSU)

This indicator measures the difference between phosphorus inputs (as fertilizer) and outputs (as harvested crops) as a proxy of excessive phosphorus fertilizer use that can contribute to the eutrophication of water bodies. A score of 100 indicates no surplus, while a score of 0 indicates worst performance. Data supporting this metric come from the FAOSTAT crop nutrient budget database.

Relative Crop Yield (RCY)

This indicator measures the average yield of 17 major crops relative to estimates of the country-specific maximum attainable yield of those crops based on climate and history. An efficient agricultural system would produce crops at this upper limit, while an inefficient system would be making poor use of its arable land. A score of 100 indicates full yield gap closure, and a score of 0 indicates worst performance. Data supporting this metric come from the FAOSTAT crop production database.

Note: Countries in which the 17 major crops represent less than 5% of total area harvested are not scored on this indicator. Weight assigned to this indicator is reapportioned to other indicators within the Agriculture issue category.

Pesticide Pollution Risk (PRS)

This indicator summarizes the risk to biodiversity from pesticide pollution and is calculated as the geometric mean of a country's pesticide risk scores. A score of 100 indicates minimal risk, and a score of 0 indicates worst performance. Data come from Maggi & Tang (2024) and Tang et al. (2021).

Water Resources (WRS)

The Water Resources issue category measures the extent to which humans are mitigating our threats to aquatic ecosystems through the generation and mismanagement of wastewater. It consists of one indicator, the percentage of wastewater safely treated.

Wastewater Treatment (WWT)

This indicator measures the percentage of domestic wastewater that is safely treated. A score of 100 indicates 100% treatment, and a score of 0 indicates 0% treatment. Data primarily come from UN-Water, with supplementary data from UNSD/UNEP country questionnaires and Jones et al. (2020).

Climate Change Policy Objective (PCC)

The Climate Change policy objective comprises 30% of the total EPI score and is made up of a single issue category, Climate Change Mitigation.

Climate Change Mitigation (CCH)

The Climate Change Mitigation issue category measures progress to combat global climate change, which exacerbates other environmental threats and imperils human health and safety. It is composed of nine indicators: emission trends for four greenhouse gases (CO2, CH4, F-gases, and N2O) and one climate pollutant (black carbon); net carbon fluxes from land cover change; projected total GHG emission in 2050; and GHG emission trends relative to emission intensity or per capita emission.

CO2 emission trend (CDA)

We measure the average annual growth rate of carbon dioxide (CO2) emissions over the years 2015 to 2024 and adjust for economic trends to isolate change due to policy effort rather than economic fluctuation. A score of 100 indicates a country is cutting emissions by at least 8.3% per year, and a score of 0 indicates that a country is increasing emissions by 8.3% per year or more. Data come from the Global Carbon Budget.

CH4 emission trend (CHA)

We measure the average annual growth rate of methane (CH4) emissions over the years 2015 to 2024 and adjust for economic trends to isolate change due to policy effort rather than economic fluctuation. A score of 100 indicates a country is cutting emissions by at least 5.3% per year, and a score of 0 indicates that a country is increasing emissions by 5.3% per year or more. Data come from EDGAR.

N2O emission trend (NDA)

We measure the average annual growth rate of nitrous oxide (N2O) emissions over the years 2015 to 2024 and adjust for economic trends to isolate change due to policy effort rather than economic fluctuation. A score of 100 indicates a country is cutting emissions by at least 2.87% per year, and a score of 0 indicates that a country is increasing emissions by 2.87% per year or more. Data come from EDGAR.

F-gas emission trend (FGA)

We measure the average annual growth rate of fluorinated gases (F-gases) emissions over the years 2015 to 2024. A score of 100 indicates a country is cutting emissions by at least 12% per year, and a score of 0 indicates that a country is increasing emissions by 12% per year or more. Data come from EDGAR.

Black Carbon emission trend (BCA)

We measure the average annual growth rate of black carbon emissions over the years 2014 to 2023 and adjust for economic trends to isolate change due to policy effort rather than economic fluctuation. A score of 100 indicates a country is cutting emissions by at least 4.5% per year, and a score of 0 indicates that a country is increasing emissions by 4.5% per year or more. Data come from the Community Emissions Data System.

GHG emission trend, adj. per capita (GTP)

This indicator balances two measures of climate performance often in tension: GHG emission trend and per capita GHG emissions. While a negative trend, captured by the average annual percent change in emissions over the period 2015–2024, is desirable, countries with higher per capita emissions should be held to higher standards of good performance. And low per capita emissions cannot be rewarded if a country's GHG emissions are increasing. Blending these metrics produces an indicator where 100 signals emission reductions commensurate with current per capita emission levels, and 0 signals either increasing emissions or higher per capita emission levels with insufficient reductions. Data come from EDGAR, Global Carbon Budget, World Bank Database, and IMF.

GHG emission trend, adj. per GDP (GTI)

This indicator balances two measures of climate performance often in tension: GHG emission trend and emission intensity (GHG per unit of GDP). While a negative trend, captured by the average annual percent change in emissions over the period 2015–2024, is desirable, countries with higher emission intensities should be held to higher standards of good performance. And countries with low emission intensities cannot be rewarded if their GHG emissions are increasing. Blending these metrics produces an indicator where 100 signals emission reductions commensurate with current emission intensity levels, and 0 signals either increasing emissions or high emission intensities with insufficient reductions. Data come from EDGAR, Global Carbon Budget, World Bank Database, and IMF.

Projected emissions 2050 (GHO)

This indicator gauges whether countries are on track to reach zero emissions of four greenhouse gases (carbon dioxide, methane, fluorinated gases, and nitrous oxide) by 2050. Emissions in 2050 are a linear projection of average emissions over the period 2015–2024, as a percentage of emissions in 2024. A score of 100 indicates that a country will reach zero emissions by 2050, and a score of 0 indicates that emissions will be 1.5× higher than in 2024. Data come from EDGAR and Global Carbon Budget.

Carbon flux from land use change (LUF)

This indicator measures whether changes in a country's land use, land cover, and forestry over the last decade have resulted in net positive or negative carbon fluxes, relative to hectares of forested area. A score of 100 indicates that a country has been a net carbon sink, and a score of 0 indicates very high flows of carbon from the land to the atmosphere. Data come from the Global Carbon Budget.

Note: Countries with less than 2,000 hectares of tree cover in 2000 are not scored on this indicator. Weight assigned to the Forests issue category is reapportioned to other issue categories within the Ecosystem Vitality policy objective.