Pellet fuelPellet fuels (or pellets) are a type of solid fuel made from compressed organic material. Pellets can be made from any one of five general categories of biomass: industrial waste and co-products, food waste, agricultural residues, energy crops, and untreated lumber. Wood pellets are the most common type of pellet fuel and are generally made from compacted sawdust and related industrial wastes from the milling of lumber, manufacture of wood products and furniture, and construction.
HoloceneThe Holocene (ˈhɒl.əsiːn,_-oʊ-,ˈhoʊ.lə-,-loʊ-) is the current geological epoch. It began approximately 11,700 years before 2000 CE (11,650 cal years BP, 9700 BCE or 300 HE). It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1. It is considered by some to be an interglacial period within the Pleistocene Epoch, called the Flandrian interglacial.
DeforestationDeforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated deforestation occurs in tropical rainforests. About 31% of Earth's land surface is covered by forests at present. This is one-third less than the forest cover before the expansion of agriculture, with half of that loss occurring in the last century.
Attribution of recent climate changeEfforts to scientifically ascertain and attribute mechanisms responsible for recent global warming and related climate changes on Earth have found that the main driver is elevated levels of greenhouse gases produced by human activities, with natural forces adding variability. The likely range of human-induced surface-level air warming by 2010–2019 compared to levels in 1850–1900 is 0.8 °C to 1.3 °C, with a best estimate of 1.07 °C. This is close to the observed overall warming during that time of 0.9 °C to 1.
Planetary boundariesPlanetary boundaries are a framework to describe limits to the impacts of human activities on the Earth system. Beyond these limits, the environment may not be able to self-regulate anymore. This would mean the Earth system would leave the period of stability of the Holocene, in which human society developed. Crossing a planetary boundary comes at the risk of abrupt environmental change. The framework is based on scientific evidence that human actions, especially those of industrialized societies since the Industrial Revolution, have become the main driver of global environmental change.
Ocean acidificationOcean acidification is the decrease in the pH of the Earth's ocean. Between 1950 and 2020, the average pH of the ocean surface fell from approximately 8.15 to 8.05. Carbon dioxide emissions from human activities are the primary cause of ocean acidification, with atmospheric carbon dioxide (CO2) levels exceeding 410 ppm (in 2020). CO2 from the atmosphere is absorbed by the oceans. This produces carbonic acid (H2CO3) which dissociates into a bicarbonate ion () and a hydrogen ion (H+).
Air pollutionAir pollution is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. It is also the contamination of indoor or outdoor surrounding either by chemical activities, physical or biological agents that alters the natural features of the atmosphere. There are many different types of air pollutants, such as gases (including ammonia, carbon monoxide, sulfur dioxide, nitrous oxides, methane and chlorofluorocarbons), particulates (both organic and inorganic), and biological molecules.
Water cycleThe water cycle, also known as the hydrologic cycle or the hydrological cycle, is a biogeochemical cycle that describes the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly constant over time but the partitioning of the water into the major reservoirs of ice, fresh water, saline water (salt water) and atmospheric water is variable depending on a wide range of climatic variables.
Solid fuelSolid fuel refers to various forms of solid material that can be burnt to release energy, providing heat and light through the process of combustion. Solid fuels can be contrasted with liquid fuels and gaseous fuels. Common examples of solid fuels include wood, charcoal, peat, coal, hexamine fuel tablets, dry dung, wood pellets, corn, wheat, rye, and other grains. Solid fuels are extensively used in rocketry as solid propellants. Solid fuels have been used throughout human history to create fire and solid fuel is still in widespread use throughout the world in the present day.
Land change scienceLand change science refers to the interdisciplinary study of changes in climate, land use, and land cover. Land change science specifically seeks to evaluate patterns, processes, and consequences in changes in land use and cover over time. The purpose of land change science is to contribute to existing knowledge of climate change and to the development of sustainable resource management and land use policy.
