Climate and environment glossary – I–M

A–B | C–D | E | F–G | I–M | N–P | R–S | T–Z


impact: the processes and actions that have an effect on biodiversity and human health, either positive or negative. See also effect.

impact investing: investments in companies, organisations and funds that intend to generate a measurable, beneficial social or environmental impact alongside a financial return.


Industrial Revolution: the process of economic change from predominantly manual work to machine-based manufacture (in factories) and agriculture, to one dominated by industry and machine manufacturing, beginning in Britain in the late 18th century, and soon spreading to other parts of Europe and the USA.

Intergovernmental Panel on Climate Change (IPCC): compiles the scientific evidence for climate change and publishes a periodic Assessment Report (AR) on the three core aspects of climate change: the physical science basis; impacts, adaptation and vulnerability; and mitigation of climate change. The most recently published full report is AR5 (2014); sections of AR6 have been published, with the final report due in 2022.

ISO 14001: the International Standard for writing and implementing an environmental policy.


landfill: the practice of burying waste in the ground as a means of disposal. Where engineering practices are not applied (eg geotextile lining), this can result in leachate (the smelly liquid that forms as waste decomposes) getting into the soil and into groundwater and aquifers, causing pollution. Landfilling waste also leads to a build-up of methane gas as waste decomposes. This can be captured and used as a form of renewable power, but more often than not is flared – lit and burned to avoid potential explosions.


mangrove: a tree or shrub which grows in tidal, chiefly tropical, coastal swamps. Their tangled roots grow both above and below the water, forming a crucial part of the oceanic ecosystem by providing a habitat for many marine species. The tangled roots also help to filter dirty water as it flows into the sea. Mangroves are key in the fight against climate change because of their ability to store carbon – typically more than terrestrial forests.

methane: a gas with more than 80 times the warming power of carbon dioxide over the first 20 years after it reaches the atmosphere. Around 60 per cent of the world’s methane emissions are produced by human activities, mostly from agriculture, waste disposal and fossil fuel production. Methane is also present in large quantities in Arctic permafrost and will be released into the atmosphere as the permafrost melts, further intensifying warming. See also GWP; tipping point.

mitigation: efforts to reduce or prevent greenhouse gas emissions and other negative impacts. These efforts often involve using new technologies and renewable energies, making older equipment more energy efficient, or changing management practices or consumer behaviour. Mitigation can be as complex as a plan for a new city, or as simple as improvements to a cooking stove design. See also adaptation.

Source: UNEP