A dozen lectures, workshops, events and exhibitions will be held in Zagreb, Osijek, Rijeka and Split until April 24.
British Council Croatia director Roy Cross said the festival was part of the council's global campaign intended to raise awareness about climate changes.
Croatian Science and Education Minister Dragan Primorac said the festival showed that science and education were inseparable.
The festival features an exhibition on climate systems throughout history, and an exhibition featuring the work of the Magnum Photographic agency, whose photographers have attempted to capture extreme climate changes around the world.
The festival is being held under the auspices of the Croatian Science and Education Ministry.