The native forests of Borneo have been impacted by selective logging, fire, and conversion to plantations at unprecedented scales since industrial-scale extractive industries began in the early 1970s. There is no island-wide documentation of forest clearance or logging since the 1970s. This creates an information gap for conservation planning, especially with regard to selectively logged forests that maintain high conservation potential. Analysing LANDSAT images, we estimate that 75.7% (558,060 km²) of Borneo's area (737,188 km²) was forested around 1973. Based upon a forest cover map for 2010 derived using ALOS-PALSAR and visually reviewing LANDSAT images, we estimate that the 1973 forest area had declined by 168,493 km² (30.2%) in 2010. The highest losses were recorded in Sabah and Kalimantan with 39.5% and 30.7% of their total forest area in 1973 becoming non-forest in 2010, and the lowest in Brunei and Sarawak (8.4%, and 23.1%). We estimate that the combined area planted in industrial oil palm and timber plantations in 2010 was 75,480 km², representing 10% of Borneo. We mapped 271,819 km of primary logging roads that were created between 1973 and 2010. The greatest density of logging roads was found in Sarawak, at 0.89 km km⁻², and the lowest density in Brunei, at 0.18 km km⁻². Analyzing MODIS-based tree cover maps, we estimate that logging operated within 700 m of primary logging roads. Using this distance, we estimate that 266,257 km² of 1973 forest cover has been logged. With 389,566 km² (52.8%) of the island remaining forested, of which 209,649 km² remains intact. There is still hope for biodiversity conservation in Borneo. Protecting logged forests from fire and conversion to plantations is an urgent priority for reducing rates of deforestation in Borneo.

Trans-boundary haze events in Southeast Asia are associated with large forest and peatland fires in Indonesia. These episodes of extreme air pollution usually occur during drought years induced by climate anomalies from the Pacific (El Niño Southern Oscillation) and Indian Oceans (Indian Ocean Dipole). However, in June 2013 – a non-drought year – Singapore's 24-hr Pollutants Standards Index reached an all-time record 246 (rated “very unhealthy”). Here, we show using remote sensing, rainfall records and other data, that the Indonesian fires behind the 2013 haze followed a two-month dry spell in a wetter-than-average year. These fires were short-lived (one week) and limited to a localized area in Central Sumatra (1.6% of Indonesia): burning an estimated 163,336 ha, including 137,044 ha (84%) on peat. Most burning was confined to deforested lands (82%; 133,216 ha). The greenhouse gas (GHG) emissions during this brief, localized event were considerable: 172 ± 59 Tg CO₂-eq (or 31 ± 12 Tg C), representing 5–10% of Indonesia's mean annual GHG emissions for 2000–2005. Our observations show that extreme air pollution episodes in Southeast Asia are no longer restricted to drought years. We expect major haze events to be increasingly frequent because of ongoing deforestation of Indonesian peatlands.

The Global Forest Resources Assessment 2015 shows that deforestation has slowed and afforestation has increased globally during 1990–2015. Planted forests have increasingly provided goods and services hitherto derived from natural forests, and mosaic forests in agricultural landscapes are increasing. Forest gain is occurring at higher latitudes and in richer countries whilst forest loss continues in poor countries in the tropics. Some middle income tropical countries are now also transitioning to forest gain. These transition countries are characterised by reforms to forest management and improvements in agricultural practices but also by significant expansions of planted forest, which account for ∼25–100% of gains. Forest-area estimates of the FRA align with satellite-derived estimates, with deviations of ⩽±7% globally and ⩽±17% for the tropics. Mosaics comprised of trees outside forests, remnant forest patches, and young regenerating forests constitute a modest proportion of the tropical forest estate and are seemingly well inventoried by the FRA. Extensive areas of forest experienced partial canopy cover reduction since 2000, particularly in the tropics where their area is ∼6.5 times that deforested since 1990. The likelihood of the eventual loss of these forests and a decline in their capacity to provide goods and services is a matter of concern. Demand for industrial wood and fuelwood increased 35% in the tropics since 1990, principally in poorer countries, and growth in demand will accelerate into the future, particularly in the Asia-Pacific region. Notwithstanding significant increases in forests within protected areas since 1990 to 517Mha (16.3%) globally and 379Mha (26.6%) in the tropics, increasing demands for ecological services, forest products, and climate change mitigation is likely to be met from an expanding area of planted forests more than from the declining area of natural forests, particularly in Africa. The global rate of planted-forest expansion since 1990 is close to a target rate of 2.4% per annum necessary to replace wood supplied from natural forests in the medium term, though the expansion rate has declined to 1.5% since 2005. Multiple-use forests permitting both production and conservation account for 26% of the global forest area and 17% of the tropical forest area, and have increased by 81.8Mha or 8.5% globally since 1990, with most gains in the tropics. Sustainable forest management in low-income and tropical countries remains modest, with only 37% low-income country forests covered by forest inventories. International support has proven effective at increasing this coverage since 2010