• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer

RealClimate

Climate science from climate scientists...

  • Start here
  • Model-Observation Comparisons
  • Miscellaneous Climate Graphics
  • Surface temperature graphics
You are here: Home / Archives for Extras

Extras

CO2 Fertilization

28 Nov 2004 by mike

It has sometimes been argued that the earth’s biosphere (in large part, the terrestrial biosphere) may have the capacity to sequestor much of the increased carbon dioxide (CO2) in the atmosphere associated with human fossil fuel burning. This effect is known as “CO2 fertilization” because, in the envisioned scenario, higher ambient CO2 concentrations in the atmosphere literally “fertilize” plant growth. Because plants in turn, in the process of photosynthesis, convert CO2 into oxygen, it is thus sometimes argued that such “co2 fertilization” could potentially provide a strong negative feedback on changing CO2 concentrations.

[Read more…] about CO2 Fertilization

Filed Under: Glossary

El Niño/Southern Oscillation (“ENSO”)

28 Nov 2004 by group

Translations: (Français)

A natural coupled mode of climate variability associated with both surface temperature variations tied to El Niño and atmospheric circulation changes across the equatorial Pacific (see also ‘Southern Oscillation Index’). Term was first coined by Rasmusson and Carpenter (1982). More information on ENSO can be found here.

Filed Under: Glossary

Empirical Orthogonal Function (“EOF”)

28 Nov 2004 by group

Spatial pattern tied to a particular mode of time/space variance in a spatiotemporal data set (see also “Principal Components Analysis or “PCA”).

Filed Under: Glossary

Energy Balance Model (“EBM”)

28 Nov 2004 by group

Simple climate model consisting of a uniform ocean and atmosphere that respond thermodynamically, but not dynamically, to changes in radiative forcing.

Filed Under: Glossary

Forcings

28 Nov 2004 by group

Translations: (Français)

Forcings in the climate sense are external boundary conditions or inputs to a climate model. Obviously changes to the sun’s radiation are external, and so that is always a forcing. The same is true for changes to the Earth’s orbit (“Milankovitch cycles”). Things get a little more ambigous as you get closer to the surface. In models that do not contain a carbon cycle (and that is most of them), the level of CO2 is set externally, and so that can be considered a forcing too. However, in models that contain a carbon cycle, changes in CO2 concentrations will occur as a function of the climate itself and in changes in emissions from industrial activity. In that case, CO2 levels will be a feedback, and not a forcing. Almost all of the elements that make up the atmosphere can be considered feedbacks on some timescale, and so defining the forcing is really a function of what feedbacks you allow in the model and for what purpose you are using it. A good discussion of recent forcings can be found in Hansen et al (2002) and in Schmidt et al (2004).

Filed Under: Glossary

General Circulation Model (“GCM”)

28 Nov 2004 by group

Translations: (Français)

Typically refers to a three-dimensional model of the global atmosphere used in climate modeling (often erroneously called “Global Climate Model”). This term often requires additional qualification (e.g., as to whether or not the atmosphere is fully coupled to an ocean–see ‘Atmosphere-Ocean General Circulation Model’).

The length scales that are resolved in these models is typically on the order of 100s of kilometers (i.e. features that size or smaller are not directly resolved). The timestep for the models (how often the fields are updated) is usually 20 minutes to an hour. Thus in any day there would be 24 to 72 loops of the main calculations.

The basic variables are the temperature, humidity, liquid/ice water content and atmospheric mass. The physics usually consists of advection, radiation calculations, surface fluxes (latent, sensible heat etc.), convection, turbulence and clouds. More elaborate Earth System models often contain tracers related to atmospheric chemistry and aerosols (including dust and sea salt).

Filed Under: Glossary

Greenhouse Gases (“GHGs”)

28 Nov 2004 by group

Greenhouse Gases (GHGs) refer to any atmospheric gases that absorb long wave radiation (emitted from the surface), thereby causing the planet’s surface to be warmer than it would be otherwise. These gases include water vapour, CO2, CH4, N2O, many CFCs (chloro-fluro-carbons). Ozone (O3) as well as being a shortwave absorber (in the ultra-violet range) also has a small longwave greenhouse effect. Other components of the atmosphere also absorb longwave radition (specifically aerosols and clouds) and hence have a greenhouse effect while not being gases themselves.
Oxygen (O2) and nitrogen (N2) while being the dominant gases in the atmosphere do not have significant absorption lines in the relevant longwave range and so are not greenhouse gases.

Filed Under: Glossary

Hockey Stick

28 Nov 2004 by group

Instrumental data describing large-scale surface temperature changes are only available for roughly the past 150 years. Estimates of surface temperature changes further back in time must therefore make use of the few long available instrumental records and natural archives or ‘climate proxy’ indicators, such as tree rings, corals, ice cores and lake sediments, and historical documents, to reconstruct patterns of past surface temperature change. Due to the paucity of data in the Southern Hemisphere, recent studies have emphasized the reconstruction of Northern Hemisphere (NH) mean, rather than global mean temperatures over roughly the past 1000 years.

[Read more…] about Hockey Stick

Filed Under: Glossary

Isotopes

28 Nov 2004 by Gavin

Isotopes can be thought of as different ‘flavours’ of a particular element (such as oxygen or carbon), that are distinguished by the number of neutrons in their nucleus (and hence their atomic mass). Carbon for instance most commonly has a mass of 12 (written as 12C), but there are also a small fraction of carbon atoms with mass 13 and 14 (13C and 14C), similarly oxygen is normally 16O, but with small amounts of 17O and 18O. All of the isotopes of an element behave in similar way chemically. However, because the mass of each isotope is slightly different there are certain physical processes that will discriminate (or ‘fractionate’) between them. For instance, during evaporation of water, it is slightly easier for the lighter isotopes to escape from the liquid, and so water vapour generally has less 18O than the liquid water from which it came. Because of these physical effects, looking at the ratio of one isotope to another can often be very useful in tracing where these atoms came from.

Filed Under: Glossary

Little Ice Age (“LIA”)

28 Nov 2004 by group

Translations: (Français)

Term originally introduced in the late 1930s by Matthes (1939) to describe a broad interval of the late Holocene during which significant glacial advances were observed. In the climatological literature the LIA has now come to be used to characterize a more recent, shorter recent interval from around A.D. 1300 to 1450 until A.D. 1850 to 1900 during which regional evidence in Europe and elsewhere suggest generally cold conditions. Variations in the literature abound with regard to the precise definition, and the term is often used by paleoclimatologists and glaciologists without formal dates attached. The attribution of the term at regional scales is complicated by significant regional variations in temperature changes due to the the influence of modes of climate variability such as the North Atlantic Oscillation and the El Nino/Southern Oscillation. Indeed, the utility of the term in describing past climate changes at regional [Read more…] about Little Ice Age (“LIA”)

Filed Under: Glossary

  • « Go to Previous Page
  • Page 1
  • Interim pages omitted …
  • Page 11
  • Page 12
  • Page 13
  • Page 14
  • Page 15
  • Go to Next Page »

Primary Sidebar

Search

Search for:

Email Notification

get new posts sent to you automatically (free)
Loading

Recent Posts

  • Unforced variations: Jun 2025
  • Predicted Arctic sea ice trends over time
  • The most recent climate status
  • Unforced variations: May 2025
  • Unforced Variations: Apr 2025
  • WMO: Update on 2023/4 Anomalies

Our Books

Book covers
This list of books since 2005 (in reverse chronological order) that we have been involved in, accompanied by the publisher’s official description, and some comments of independent reviewers of the work.
All Books >>

Recent Comments

  • Paul Pukite (@whut) on Unforced variations: Jun 2025
  • Nigelj on Predicted Arctic sea ice trends over time
  • Pedro Prieto on The most recent climate status
  • Nigelj on Predicted Arctic sea ice trends over time
  • Pedro Prieto on The most recent climate status
  • Pedro Prieto on The most recent climate status
  • Pedro Prieto on The most recent climate status
  • Pedro Prieto on The most recent climate status
  • Pedro Prieto on Unforced variations: Jun 2025
  • Russell Seitz on Unforced variations: Jun 2025
  • Pedro Prieto on Predicted Arctic sea ice trends over time
  • nigelj on Predicted Arctic sea ice trends over time
  • Pedro Prieto on Predicted Arctic sea ice trends over time
  • Pedro Prieto on Predicted Arctic sea ice trends over time
  • Tomáš Kalisz on Unforced variations: Jun 2025
  • Kevin McKinney on The most recent climate status
  • Pedro Prieto on Predicted Arctic sea ice trends over time
  • Pedro Prieto on Predicted Arctic sea ice trends over time
  • Kevin McKinney on The most recent climate status
  • Kevin McKinney on The most recent climate status

Footer

ABOUT

  • About
  • Translations
  • Privacy Policy
  • Contact Page
  • Login

DATA AND GRAPHICS

  • Data Sources
  • Model-Observation Comparisons
  • Surface temperature graphics
  • Miscellaneous Climate Graphics

INDEX

  • Acronym index
  • Index
  • Archives
  • Contributors

Realclimate Stats

1,367 posts

11 pages

243,427 comments

Copyright © 2025 · RealClimate is a commentary site on climate science by working climate scientists for the interested public and journalists.