Are there certifications or professional designations that are specifically geared for economists? i.e much like the CPA and CA exists for accountants.
Separate from their academic qualifications, no there are not. The reason is that certifications generally serve two functions, either to show a legal status or where there are no academic qualifications required to show some learning process has happened that is similar to an academic designation.
To provide an example, the MD, the CPA and the PE designations have legal meaning. Their existence is postulated in state and federal law as necessary to engage in certain forms of practice, though medical doctors at the state level also have additional licensing. Federal physicians do not always have to have a state license, such a military doctors. Physicians also have higher level certifications to show skill in a narrow area to convince customers they can be trusted in that narrow area.
Beyond this, some fields are heavily populated with people who have no academic degree and for those narrower certifications are available such as CFA or licensing such as the barber's license. The barber's license is a strange throwback to when barbers did surgery, we still license barbers but the need is less apparent than it was when it started.
Economists have no legal standing. There is no field of practice that the legislators of the world have felt necessary to impose additional qualifications for beyond a doctorate. Indeed, you could have a doctorate in another field and engage in economic research and consulting. This certainly happens with finance professors, mathematicians, sociologists, psychologists and political scientists. Psychologists and mathematicians have won the Nobel for economics before.
It also is unlikely there are certifications that would be meaningful. The simplest way to determine the technical skill of an economist is to read their doctoral dissertation, or masters thesis, and their research body of work. It is an open source process, so unlike craftsmen whose work is only visible to their prior customers the work of economists is very public and very visible.
Of all professions, it should be easier to evaluate an economist than maybe any other. Certifications would do what? For whom?