Consequences and karma overlap in meaning but come from different frameworks of thought, so they are not exactly the same thing.
Consequences is a general, secular concept: it simply refers to the effects or results that follow from any action, cause, or decision. Consequences can be immediate or delayed, and they follow directly from cause-and-effect relationships that can usually be observed, explained by physics, biology, psychology, or social dynamics. For example, if you don't water a plant, it wilts — that's a consequence, not a moral judgment.
Karma is a concept rooted in Hindu, Buddhist, Jain, and Sikh philosophical and religious traditions. It refers to a moral law of cause and effect that spans not just this life but, in traditions that include reincarnation, multiple lifetimes. Karma implies that intentional actions (thoughts, words, deeds) carry an ethical weight that eventually returns to the person who acted, shaping their future circumstances or rebirths. Karma is inherently tied to morality and intention — an action's karmic effect depends on the mental state behind it, not just the physical outcome.
In casual, everyday Western usage, "karma" has been popularized and simplified to mean roughly "you get what you deserve" or "what goes around comes around," which blurs it closer to the general idea of moral consequences. In this loose colloquial sense, people often use "karma" interchangeably with "just deserts" or "consequences of one's actions."
So the key distinction is: all karma involves consequences, but not all consequences are karma. Consequences are a broad, universal, and often value-neutral concept, while karma specifically implies a cosmic, ethical, and often spiritual system of moral cause and effect tied to intention, and in many traditions, to the soul's journey across lifetimes. Whether such a system actually exists is a matter of religious and philosophical belief rather than empirical fact.