LAYERS
Wetlands
INFOGRAPHICS
World
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Biomass change
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NOTES
- Biomass. Aboveground dry vegetation in tonnes per hectare (t/ha). One hectare is 100 m × 100 m; deeper green means more biomass. CTrees.
- Change since 2000. Red shows loss, blue shows growth, in t/ha. Map changes below 10 t/ha are hidden; charts include them. CTrees.
- Loss cause. Colour identifies the estimated cause of the largest decline since 2000; deeper shades mean greater total loss, up to 150+ t/ha. Select a cause in the key to show it alone. Disturbance records.
- Wetland types. The dominant type of wetland in each pixel: the 26 wetland classes of the Global Lakes and Wetlands Database in seven groups. Paler colour means less of the ground is wetland (2–100%). Lakes, reservoirs and rivers are the basemap's own water. Select a type in the key to show it alone; point at the map for the type and share. GLWD v2.
- Biomass change. Each bar compares a year with the previous year: Retained in green, Gained in blue, and Lost stacked above by cause. Net is Gained minus Lost, shown with a + or − in the bar details. Green + blue is the biomass remaining. The two figures above compare the selected year with 2000. Select an entry below the bars to hide or show it: hiding Retained leaves each year's gains and losses, and the scale fits what is shown.
- Causes of biomass loss. Toggle between yearly loss and loss since 2000. Hover or tap a slice for tonnes and its share of losses in that period; growth is excluded.
- Attribution. Causes are estimates from disturbance records. Each year's loss takes the cause matched to that year's own decline: a dated record from that year or shortly before (one to three years, depending on how soon each kind of record shows up as lost biomass), else the regional driver estimate. Burn scars never override a farming, mining or settlement driver, since fire is often how land is cleared. Hand-drawn regional estimates count only in the years they describe. Loss since 2000 takes the cause of the largest decline. Small losses, and losses on land still above its 2000 biomass, keep their cause even though the map only draws losses over 10 t/ha. Loss with no matching record or driver estimate is Unknown; most of it is year-to-year changes under 5 t/ha, within the biomass model's own variation.
- Estimates. Charts sum total tonnes across the whole world, or the areas clicked on the map, comparing pixels with data in every year. Every area is summed in advance on a fixed grid of about 1.2 km at the equator, so the charts do not change with the zoom. Biomass values are rounded to 2.5 t/ha; model error and delayed responses affect changes. These estimates are not suitable for carbon accounting.
- Borders and selection. Borders shown (in Layers; countries at first) draws one level at a time: continents, countries, provinces (states) or districts (counties). The charts show the whole world until areas are clicked. Click areas to add them to the charts' selection, with Infographics open or closed; click one again to remove it, or clear the selection to return to the world. Regional change since 2000 shows the borders too. Changing the level starts a new selection. Continents are geographic: Russia east of the Urals, the Sinai and the rest of Asia form Asia, and islands follow their continent. Districts appear from zoom 4. Areas use the polygon interiors, including islands and excluding holes; where outlines overlap, each pixel counts in one area only, so a selection counts nothing twice. The world includes coasts and islands outside the simplified outlines. Regional colours and signed labels estimate total tonnes changed from 2000 to the selected year, across each whole area, from the same fixed grid and the charts' footprint, so a selected area shows the same totals on the map and in the charts. Pale red/blue marks smaller losses/gains; deeper colour marks larger changes. No data is left uncoloured. Boundaries are simplified for this map.
- 2026*. The asterisk marks an estimate, not observed data: 2026 biomass is estimated from the year's fires. It is a partial, fire-only estimate, built from the Copernicus GWIS burned areas mapped through late September 2026: 2025 biomass minus the expected fire loss inside them. The expected loss comes from this map's own history: for each area about 600 km across and each biomass class, the Fire loss the charts show for 2021–2025 per tonne of biomass burned in 2019–2023, two years earlier because the biomass model registers most fire loss late. It is measured on a fixed grid of about 600 m at the equator and summed for every zoom, so the map, regional totals and charts show the same 2026 fire loss. The estimate counts fire the way the historical charts do; areas with few past fires borrow from a wider area. Growth, logging, insects and all other changes are not estimated, so 2026 shows no gain and only fire loss. It is a statistical estimate, not observed 2026 biomass or a forecast of the whole year.
- Decrease rates. Annual gross biomass loss by estimated cause, in tonnes per year or as a percentage of the previous year’s biomass on the same footprint, to show whether fire, logging or other losses are growing. Select a cause to show or hide it; Unknown (small and unlabelled declines) starts hidden. The open 2026 circle is the fire estimate to date, not a full year. Historical attribution uses dominant-disturbance labels, so later events can be misclassified.
SOURCES
- CTrees · Global Aboveground BiomassYang et al., 2026 · Annual, 100 m · CC BY 4.0 · Paper
- HydroSHEDS · Global Lakes and Wetlands Database v2Lehner et al., 2025 · 15″ (about 500 m), 33 classes, wetlands grouped into 7 · CC BY 4.0 · Paper
- Natural Earth · Countries, states and provinces1:10 million · Public domain · Continents split along the Urals and Suez
- geoBoundaries · Districts (gbOpen ADM2)Runfola et al., 2020 · Simplified · Per-country open licences (CC BY 3.0 IGO, CC BY 4.0, ODbL, public domain, CC BY-SA and others) · Includes © OpenStreetMap contributors
- Copernicus GWIS · Burned areas2018–2026, for the 2026 estimate · Contains modified Copernicus Service information (2026) · 2026 provisional
- OpenFreeMap · © OpenStreetMap contributorsBasemap · ODbL