Concept
Global dimming
Related concepts (21)
Environmental effects of aviation
Aircraft engines produce gases, noise, and particulates from fossil fuel combustion, raising environmental concerns over their global effects and their effects on local air quality. Jet airliners contribute to climate change by emitting carbon dioxide (), the best understood greenhouse gas, and, with less scientific understanding, nitrogen oxides, contrails and particulates. Their radiative forcing is estimated at 1.3–1.4 that of alone, excluding induced cirrus cloud with a very low level of scientific understanding.
Stratospheric aerosol injection
Stratospheric aerosol injection is a proposed method of solar geoengineering (or solar radiation modification) to reduce global warming. This would introduce aerosols into the stratosphere to create a cooling effect via global dimming and increased albedo, which occurs naturally from volcanic winter. It appears that stratospheric aerosol injection, at a moderate intensity, could counter most changes to temperature and precipitation, take effect rapidly, have low direct implementation costs, and be reversible in its direct climatic effects.
Atmospheric methane
Atmospheric methane is the methane present in Earth's atmosphere. The concentration of atmospheric methaneone of the most potent greenhouse gasesis increasing due to methane emissions, and is causing climate change. Methane's radiative forcing (RF) of climate is direct, and it is the second largest contributor to human-caused climate forcing in the historical period. Methane is a major source of water vapour in the stratosphere through oxidation; and water vapour adds about 15% to methane's radiative forcing effect.
Urban heat island
An urban heat island (UHI) is an urban area that is significantly warmer than its surrounding rural areas due to human activities. The temperature difference is usually larger at night than during the day, and is most apparent when winds are weak. UHI is most noticeable during the summer and winter. The main cause of the UHI effect is from the modification of land surfaces. A study has shown that heat islands can be affected by proximity to different types of land cover, so that proximity to barren land causes urban land to become hotter and proximity to vegetation makes it cooler.
Chemtrail conspiracy theory
The chemtrail conspiracy theory is the erroneous belief that long-lasting condensation trails left in the sky by high-flying aircraft are actually "chemtrails" consisting of chemical or biological agents, sprayed for nefarious purposes undisclosed to the general public. Believers in this conspiracy theory say that while normal contrails dissipate relatively quickly, contrails that linger must contain additional substances.
Instrumental temperature record
The instrumental temperature record is a record of temperatures within Earth's climate based on direct, instrument-based measurements of air temperature and ocean temperature. Instrumental temperature records are distinguished from indirect reconstructions using climate proxy data such as from tree rings and ocean sediments. Instrument-based data are collected from thousands of meteorological stations, buoys and ships around the globe.
Polar amplification
Polar amplification is the phenomenon that any change in the net radiation balance (for example greenhouse intensification) tends to produce a larger change in temperature near the poles than in the planetary average. This is commonly referred to as the ratio of polar warming to tropical warming. On a planet with an atmosphere that can restrict emission of longwave radiation to space (a greenhouse effect), surface temperatures will be warmer than a simple planetary equilibrium temperature calculation would predict.
Ground-level ozone
Ground-level ozone (O3), also known as surface-level ozone and tropospheric ozone, is a trace gas in the troposphere (the lowest level of the Earth's atmosphere), with an average concentration of 20–30 parts per billion by volume (ppbv), with close to 100 ppbv in polluted areas. Ozone is also an important constituent of the stratosphere, where the ozone layer (2 to 8 parts per million ozone) exists which is located between 10 and 50 kilometers above the Earth's surface.
Dimethyl sulfide
Dimethyl sulfide (DMS) or methylthiomethane is an organosulfur compound with the formula . The simplest thioether, it is a flammable liquid that boils at and has a characteristic disagreeable odor. It is a component of the smell produced from cooking of certain vegetables, notably maize, cabbage, beetroot, and seafoods. It is also an indication of bacterial contamination in malt production and brewing. It is a breakdown product of dimethylsulfoniopropionate (DMSP), and is also produced by the bacterial metabolism of methanethiol.
Haze
Haze is traditionally an atmospheric phenomenon in which dust, smoke, and other dry particulates suspended in air obscure visibility and the clarity of the sky. The World Meteorological Organization manual of codes includes a classification of particulates causing horizontal obscuration into categories of fog, ice fog, steam fog, mist, haze, smoke, volcanic ash, dust, sand, and snow. Sources for particles that cause haze include farming (ploughing in dry weather), traffic, industry, windy weather, volcanic activity and wildfires.