Climate Vocabulary, Part 1
Welcome back! Today I am sharing a series of terms that are helpful to know when learning about climate science and climate change. Many of the definitions will come from an excellent glossary provided by IPCC. Who’s that? Keep reading…
IPCC
The Intergovernmental Panel on Climate Change, IPCC, is the United Nations body for assessing the science related to climate change (www.ipcc.ch). It was created to provide policymakers with regular scientific assessments on climate change, its implications and potential future risks, as well as to put forward adaptation and mitigation options. Created by the United Nations Environment Programme (UN Environment) and the World Meteorological Organization (WMO) in 1988, the IPCC has 195 Member countries.
The IPCC produces reports, most famously its Assessment Reports, which determine the state of knowledge on climate change. They identify where there is agreement in the scientific community on topics related to climate change, and where further research is needed. The most recent set is AR6, the sixth assessment reports. This is a series of three major reports, by three internation working groups. Working group 1 describes the physical science basis for the current understanding of climate in the WG1 report. Working group 2 focuses its report on climate impacts and adaptation, discussing ecosystems, human systems, and the ways those are vulnerable or managing an adaptation well. Working group 3 examines global emissions, mitigation methods, plans, and pledges, and examines progress.
Climate
The IPCC AR6 glossary (apps.ipcc.ch/glossary/) defines climate as “the average weather, or more rigorously as the statistical description in terms of the mean and variability of relevant quantities over a period of time ranging from months to thousands or millions of years. The classical period for averaging these variables is 30 years, as defined by the World Meteorological Organization (WMO). The relevant quantities are most often surface variables such as temperature, precipitation and wind. Climate in a wider sense is the state, including a statistical description, of the climate system.”
Climate System
That glossary describes it thus:
“The global system [consists] of five major components: the atmosphere, the hydrosphere, the cryosphere, the lithosphere and the biosphere and the interactions between them. The climate system changes in time under the influence of its own internal dynamics and because of external forcings such as volcanic eruptions, solar variations, orbital forcing, and anthropogenic forcings such as the changing composition of the atmosphere and land-use change.”
Atmosphere
“The gaseous envelope surrounding the Earth, divided into five layers – the troposphere which contains half of the Earth’s atmosphere, the stratosphere, the mesosphere, the thermosphere, and the exosphere, which is the outer limit of the atmosphere. The dry atmosphere consists almost entirely of nitrogen (78.1% volume mixing ratio) and oxygen (20.9% volume mixing ratio), together with a number of trace gases, such as argon (0.93 % volume mixing ratio), helium and radiatively active greenhouse gases (GHGs) such as carbon dioxide (CO2) (0.04% volume mixing ratio), methane (CH4), nitrous oxide (N2O) and ozone (O3). In addition, the atmosphere contains the GHG water vapour (H2O), whose concentrations are highly variable (0–5% volume mixing ratio) as the sources (evapotranspiration) and sinks (precipitation) of water vapour show large spatio-temporal variations, and atmospheric temperature exerts a strong constraint on the amount of water vapour an air parcel can hold. The atmosphere also contains clouds and aerosols.” (IPCC AR6 Glossary)
Hydrosphere
“The component of the climate system comprising liquid surface and subterranean water, such as in oceans, seas, rivers, freshwater lakes, underground water, wetlands, etc.” (IPCC AR6 glossary)
Cryosphere
“The components of the Earth system at and below the land and ocean surface that are frozen, including snow cover, glaciers, ice sheets, ice shelves, icebergs, sea ice, lake ice, river ice, permafrost and seasonally frozen ground.” (IPCC AR6 glossary)
Lithosphere
“The upper layer of the solid Earth, both continental and oceanic, which comprises all crustal rocks and the cold, mainly elastic part of the uppermost mantle. Volcanic activity, although part of the lithosphere, is not considered as part of the climate system, but acts as an external forcing factor.” (IPCC AR6 glossary)
Biosphere
“The part of the Earth system comprising all ecosystems and living organisms, in the atmosphere, on land (terrestrial biosphere) or in the oceans (marine biosphere), including derived dead organic matter, such as litter, soil organic matter and oceanic detritus.”
Climate Change
From the glossary: “A change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties and that persists for an extended period, typically decades or longer. Climate change may be due to natural internal processes or external forcings such as modulations of the solar cycles, volcanic eruptions and persistent anthropogenic changes in the composition of the atmosphere or in land use. Note that the United Nations Framework Convention on Climate Change (UNFCCC), in its Article 1, defines climate change as: ‘a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods’. The UNFCCC thus makes a distinction between climate change attributable to human activities altering the atmospheric composition and climate variability attributable to natural causes.”
United Nations Framework Convention on Climate Change
Preventing “dangerous” human interference with the climate system is the ultimate aim of the Convention (their website is unfccc.int).
The United Nations Framework Convention on Climate Change (the Convention or UNFCCC) was adopted at the United Nations Headquarters, New York on the 9 May 1992. The Convention entered into force on 21 March 1994, in accordance with Article 23, after the 50th instrument of ratification, acceptance, approval or accession had been deposited. Currently, there are 198 Parties (197 States and 1 regional economic integration organization) to the UNFCCC.
Some detail: The UNFCCC borrowed a very important line from one of the most successful multilateral environmental treaties in history (the Montreal Protocol, in 1987): it bound member states to act in the interests of human safety even in the face of scientific uncertainty. The ultimate objective of the Convention is to stabilize greenhouse gas concentrations "at a level that would prevent dangerous anthropogenic (human induced) interference with the climate system." It states that "such a level should be achieved within a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened, and to enable economic development to proceed in a sustainable manner." Industrialized countries (Annex I) have to report regularly on their climate change policies and measures, including issues governed by the Kyoto Protocol (for countries which have ratified it). They must also submit an annual inventory of their greenhouse gas emissions, including data for their base year (1990)and all the years since. Developing countries (Non-Annex I Parties) report in more general terms on their actions both to address climate change and to adapt to its impacts - but less regularly than Annex I Parties do, and their reporting is contingent on their getting funding for the preparation of the reports, particularly in the case of the Least Developed Countries.
Anthropogenic
“Resulting from or produced by human activities.” (IPCC AR6 Glossary)
Okay, thanks for reading climate! I’m hoping to share a great book, ‘What if we get it right?’, and do another data analysis post on climate stripes, in the near future.
