The Keeling Curve is a graph of the accumulation of carbon dioxide in the Earth's atmosphere based on continuous measurements taken at the Mauna Loa Observatory on the island of Hawaii from 1958 to the present day. The curve is named for the scientist Charles David Keeling, who started the monitoring program and supervised it until his death in 2005.
Keeling's measurements showed the first significant evidence of rapidly increasing carbon dioxide (CO2) levels in the atmosphere. According to Naomi Oreskes, Professor of History of Science at Harvard University, the Keeling curve is one of the most important scientific works of the 20th century. Many scientists credit the Keeling curve with first bringing the world's attention to the current increase of in the atmosphere.
Prior to the 1950s, measurements of atmospheric concentrations had been taken on an ad hoc basis at a variety of locations. In 1938, engineer and amateur meteorologist Guy Stewart Callendar compared datasets of atmospheric from Kew in 1898–1901, which averaged 274 parts per million by volume (ppmv), and from the eastern United States in 1936–1938, which averaged 310 ppmv, and concluded that concentrations were rising due to anthropogenic emissions. However, Callendar's findings were not widely accepted by the scientific community due to the patchy nature of the measurements.
Charles David Keeling, of Scripps Institution of Oceanography at UC San Diego, was the first person to make frequent regular measurements of atmospheric CO2 concentrations in Antarctica, and on Mauna Loa, Hawaii from March 1958 onwards. Keeling had previously tested and employed measurement techniques at locations including Big Sur near Monterey, rain forests of the Olympic Peninsula in Washington state, and high mountain forests in Arizona. He observed strong diurnal behavior of CO2, with excess CO2 at night due to respiration by plants and soils, and afternoon values representative of the "free atmosphere" over the Northern hemisphere.
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
This course is an introduction to economic theory applied to environmental issues. It presents the methods used to assess environmental impacts and natural resources as well as environmental regulatio
Ce cours est divisé en deux partie. La première partie présente le langage Python et les différences notables entre Python et C++ (utilisé dans le cours précédent ICC). La seconde partie est une intro
Explores sustainable urban development in Switzerland, addressing material substitution, building demolition, ecosystem restoration, and public policy instruments.
Greenhouse gases are those gases in the atmosphere that raise the surface temperature of planets such as the Earth. What distinguishes them from other gases is that they absorb the wavelengths of radiation that a planet emits, resulting in the greenhouse effect. The Earth is warmed by sunlight, causing its surface to radiate heat, which is then mostly absorbed by water vapor (), carbon dioxide (), methane (), nitrous oxide (), and ozone (). Without greenhouse gases, the average temperature of Earth's surface would be about , rather than the present average of .
In 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.
An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper ones, and an ice core contains ice formed over a range of years. Cores are drilled with hand augers (for shallow holes) or powered drills; they can reach depths of over two miles (3.2 km), and contain ice up to 800,000 years old. The physical properties of the ice and of material trapped in it can be used to reconstruct the climate over the age range of the core.
The long residence time of carbon in forests and soils means that both the current state and future behavior of the terrestrial biosphere are influenced by past variability in climate and anthropogenic land use. Over the last half-millennium, European terr ...
Despite a large number of studies, out of all drivers of radiative forcing, the effect of aerosols has the largest uncertainty in global climate model radiative forcing estimates. There have been studies of aerosol optical properties in climate models, but ...
Two Himalayan ice cores display a factor-two decreasing trend of air content over the past two millennia, in contrast to the relatively stable values in Greenland and Antarctica ice cores over the same period. Because the air content can be related with th ...