While there’s a common understanding of the urgency to tackle climate change, some confusion and questions remain about, for example, the human impact on climate change, the thinking behind the 2 °C limit for global warming and how a rising global temperature affects our planet.
Implementing climate action measures requires businesses and all other stakeholders to understand the scientific realities, hence we’ll be covering in this and the two following articles of our “ESG Essentials for Corporates” series climate change basics, which are relevant to corporate decision makers, but also to anyone else.
GHG: Greenhouse gases trap the sun’s heat. They include carbon dioxide, methane, nitrogen oxide and chlorofluorocarbons.
WMO: The World Meteorological Organization is the United Nations’ specialist agency for meteorology (weather and climate), operational hydrology and related geophysical sciences.
Intergovernmental Panel on Climate Change (IPCC): A committee of climatologists, meteorologists, geographers and other scientists, established in 1988 by the WMO and the United Nations Environment Programme (UNEP) to assess the science related to climate change.
UNFCCC: The United Nations Framework Convention on Climate Change is an international environmental treaty negotiated at the United Nations Conference on Environment and Development in 1992. Its objective is to "stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system."
The long history of climate science and modelling
Since the 19th century, climatologists and other scientists have contributed to a better understanding of our climate system, collecting and feeding a vast amount of monitoring data into complex computer models, which show how variations in contributing climate factors affect each other and how any climate changes affect ecosystems and human life.
Two key discoveries: in 1861, Irish physicist, John Tyndall, recognised the natural greenhouse effect and suggested that changes in the atmospheric composition could result in climatic variations. The natural greenhouse effect is caused by so-called greenhouse gases (GHG), which occur naturally in the atmosphere. GHG trap the sun’s heat that reflects back up into the atmosphere, acting like the insulating glass walls of a greenhouse. Without the natural greenhouse effect our planet would be too cold to support life, however, a higher concentration of GHG causes the earth to heat up too much.
In 1896, Swedish chemist, Svante Arrhenius, created the first model that measured the influence of carbon dioxide, the most prominent of the GHGs, in the atmosphere and found that an increase or decrease of the quantity of CO2 results in an increases or decrease in the global temperature in nearly arithmetic progression.
Timeline of Climate Change