Climate change feedbackClimate change feedbacks are effects of global warming that amplify or diminish the effect of forces that initially cause the warming. Positive feedbacks enhance global warming while negative feedbacks weaken it. Feedbacks are important in the understanding of climate change because they play an important part in determining the sensitivity of the climate to warming forces. Climate forcings and feedbacks together determine how much and how fast the climate changes.
Land coverLand cover is the physical material at the surface of Earth. Land covers include grass, asphalt, trees, bare ground, water, etc. Earth cover is the expression used by ecologist Frederick Edward Clements that has its closest modern equivalent being vegetation. The expression continues to be used by the United States Bureau of Land Management. There are two primary methods for capturing information on land cover: field survey, and analysis of remotely sensed imagery.
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.
ClimateClimate is the long-term weather pattern in a region, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorological variables that are commonly measured are temperature, humidity, atmospheric pressure, wind, and precipitation. In a broader sense, climate is the state of the components of the climate system, including the atmosphere, hydrosphere, cryosphere, lithosphere and biosphere and the interactions between them.
Ice–albedo feedbackIce–albedo feedback is a positive feedback climate process where a change in the area of ice caps, glaciers, and sea ice alters the albedo and surface temperature of a planet. Ice is very reflective, therefore it reflects far more solar energy back to space than the other types of land area or open water. Ice–albedo feedback plays an important role in global climate change. For instance, at higher latitudes, warmer temperatures melt the ice sheets.
Climate changeIn common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global average temperature is more rapid than previous changes, and is primarily caused by humans burning fossil fuels. Fossil fuel use, deforestation, and some agricultural and industrial practices increase greenhouse gases, notably carbon dioxide and methane.
Climate modelNumerical climate models use quantitative methods to simulate the interactions of the important drivers of climate, including atmosphere, oceans, land surface and ice. They are used for a variety of purposes from study of the dynamics of the climate system to projections of future climate. Climate models may also be qualitative (i.e. not numerical) models and also narratives, largely descriptive, of possible futures.
LandLand, also known as dry land, ground, or earth, is the solid terrestrial surface of Earth not submerged by the ocean or another body of water. It makes up 29.2% of Earth's surface and includes all continents and islands. Earth's land surface is almost entirely covered by regolith, a layer of rock, soil, and minerals that forms the outer part of the crust. Land plays important roles in Earth's climate system, being involved in the carbon cycle, nitrogen cycle, and water cycle.
Climate riskClimate risk refers to risk assessments based on formal analysis of the consequences, likelihoods and responses to the impacts of climate change and how societal constraints shape adaptation options. Common approaches to risk assessment and risk management strategies based on natural hazards have been applied to climate change impacts although there are distinct differences. Based on a climate system that is no longer staying within a stationary range of extremes, climate change impacts are anticipated to increase for the coming decades despite mitigation efforts.
Climate variability and changeClimate variability includes all the variations in the climate that last longer than individual weather events, whereas the term climate change only refers to those variations that persist for a longer period of time, typically decades or more. Climate change may refer to any time in Earth's history, but the term is now commonly used to describe contemporary climate change. Since the Industrial Revolution, the climate has increasingly been affected by human activities.
Abrupt climate changeAn abrupt climate change occurs when the climate system is forced to transition at a rate that is determined by the climate system energy-balance, and which is more rapid than the rate of change of the external forcing, though it may include sudden forcing events such as meteorite impacts. Abrupt climate change therefore is a variation beyond the variability of a climate. Past events include the end of the Carboniferous Rainforest Collapse, Younger Dryas, Dansgaard-Oeschger events, Heinrich events and possibly also the Paleocene–Eocene Thermal Maximum.
Subarctic climateThe subarctic climate (also called subpolar climate, or boreal climate) is a continental climate with long, cold (often very cold) winters, and short, warm to cool summers. It is found on large landmasses, often away from the moderating effects of an ocean, generally at latitudes from 50°N to 70°N, poleward of the humid continental climates. Subarctic or boreal climates are the source regions for the cold air that affects temperate latitudes to the south in winter.
Oceanic climateAn oceanic climate, also known as a marine climate, is the temperate climate sub-type in Köppen classification represented as Cfb, typical of west coasts in higher middle latitudes of continents, generally featuring cool summers and mild winters (for their latitude), with a relatively narrow annual temperature range and few extremes of temperature. Oceanic climates can be found in both hemispheres generally between 45 and 63 latitude, most notably in northwestern Europe, northwestern America, as well as New Zealand.
Land useLand use involves the management and modification of natural environment or wilderness into built environment such as settlements and semi-natural habitats such as arable fields, pastures, and managed woods. Land use by humans has a long history, first emerging more than 10,000 years ago. It has been defined as "the purposes and activities through which people interact with land and terrestrial ecosystems" and as "the total of arrangements, activities, and inputs that people undertake in a certain land type.
Climate sensitivityClimate sensitivity is a measure of how much Earth's surface will cool or warm after a specified factor causes a change in its climate system, such as how much it will warm for a doubling in the atmospheric carbon dioxide () concentration. In technical terms, climate sensitivity is the average change in global mean surface temperature in response to a radiative forcing, which drives a difference between Earth's incoming and outgoing energy.
Instrumental temperature recordThe 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.
Continental climateContinental climates often have a significant annual variation in temperature (warm summers and cold winters). They tend to occur in the middle latitudes (40 to 55 north), within large landmasses where prevailing winds blow overland bringing some precipitation, and temperatures are not moderated by oceans. Continental climates occur mostly in the Northern Hemisphere due to the large landmasses found there.
Humid continental climateA humid continental climate is a climatic region defined by Russo-German climatologist Wladimir Köppen in 1900, typified by four distinct seasons and large seasonal temperature differences, with warm to hot (and often humid) summers and cold (sometimes severely cold in the northern areas) winters. Precipitation is usually distributed throughout the year but often does have dry seasons. The definition of this climate regarding temperature is as follows: the mean temperature of the coldest month must be below or depending on the isotherm, and there must be at least four months whose mean temperatures are at or above .
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.
Effects of climate changeClimate change affects the physical environment, ecosystems and human societies. Changes in the climate system include an overall warming trend, more extreme weather and rising sea levels. These in turn impact nature and wildlife, as well as human settlements and societies. The effects of human-caused climate change are broad and far-reaching, especially if significant climate action is not taken. The projected and observed negative impacts of climate change are sometimes referred to as the climate crisis.
