This is the 5413th most frequent Spanish word.
mundiales
"World" or "worldwide" (plural form).
In this sentence, 'mundiales' serves as a plural adjective describing 'desastres', signifying that these disasters occur on a global scale.
Los desastres mundiales afectan a todos.
Global disasters affect everyone.
Finally, 'mundiales' is applied as a plural adjective to 'avances' to convey that these improvements are worldwide in reach and impact.
Los avances mundiales en tecnología han beneficiado a la humanidad.
Worldwide advancements in technology have benefited humanity.
Here, 'mundiales' is used as a plural adjective modifying 'campeonatos' to indicate that these championships are of world-level scope.