The phrase "a major effect of" is correct and usable in written English.
It can be used when discussing the significant impact or influence of a particular factor or event on something else.
Example: "The study revealed that a major effect of climate change is the increase in extreme weather events."
Alternatives: "a significant impact of" or "a substantial influence of".
A heavy dependence on human muscle was the principal cause and a major effect of this low level of development.
"A major effect of raising pay checks for earners at the bottom of the wage scale is that these earners are likely to spend more of their income on local goods and service than higher-income earners.
A major effect of daylight time is that it leaves more hours of natural light at the end of the day, reducing the time between sunset and the typical bedtime.
A major effect of urbanisation on biota stems from artificial structures placed in aquatic systems.
A major effect of different monetary chip equivalents is observed only when the proposer has a higher chip value.
A major effect of melimine was on the integrity of the cytoplasmic membrane both for P. aeruginosa and S. aureus.
The study revealed a major effect of post-depositional processes and quantification methods on the final anthracological interpretation.
Creating revertant viruses and subsequent neurovirulence test on mice demonstrated a major effect of residue 138 and cooperatively effect of residue 279 (Yang et al., 2017).
A major effect of the atmosphere on optical beams is the rapid attenuation of their power when they propagate through obscurations (haze, fog, snow and rain).
A major effect of space weather on the ionosphere is the ability of solar-terrestrial processes to modulate and structure electron density.
Due to short duration of the anesthesia and short recovery time, a major effect of anesthesia on GI motility is not expected.
