EF or ef may refer to:
The effects of global warming are the environmental and social changes caused (directly or indirectly) by human emissions of greenhouse gases.
The English Football League Championship (often referred to as the Championship for short or the Sky Bet Championship for sponsorship reasons) is the highest division of the English Football League (EFL) and second-highest overall in the English football league system after the Premier League.
Efficient energy use, sometimes simply called energy efficiency, is the goal to reduce the amount of energy required to provide products and services.
An effects unit or effects pedal is an electronic or digital device that alters the sound of a musical instrument or other audio source.
The effects of global warming include its effects on human health. The observed and projected increased frequency and severity of climate related impacts will further exacerbate the effects on human health.
The 1986 Chernobyl disaster triggered the release of substantial amounts of radioactive contamination into the atmosphere in the form of both particulate and gaseous radioisotopes.