Knock-on effect
Knock-on effect is a phrase that has become increasingly more common in English, for a variety of uses. It refers to a secondary change, indirect, or a cumulative response to an initial adjustment or input. This may be known, unknown or unintended.
As a phrase it is likely to have originated in the sciences, in particular physics, where an example of its use is “Ejected, produced, or caused as a result of the collision of an atomic or sub-atomic particle with an atom.” (“Knock-on protons produced by 3MeV neutrons would not..produce visible flashes.” Nature, 1971.) Its use today can be found in relation to various types of both human-made and natural systems engineering.
In construction projects it may arise in project management and programming discussions. For example the knock on effect of the windows being the wrong size, was that the second fix was delayed by 6 weeks, which impacted the overall programme, costs and delivery date.
In connection to climate change, knock-on effects are more general ways to describe phenomena such as the cascade effect or feedback loops. These describe how the climate changing, primarily temperature increase has consequential impacts on a variety of the earth systems, from hydrological to ecological systems. For example the knock-on effect of temperature change is more extreme weather patterns, or the knock-on effect of permafrost melting is that higher levels of methane are released into the atmosphere thus increasing climate change risks.
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