In much of the world, (liberal) democracy (in a broad sense) is seen as the best (or least bad) system of government, and in the 20th and 21st century, living standards have improved markedly in countries ruled by such systems and clearly outperformed competing systems, such as (attempts at) socialist/communist one-party rule with a planned economy, on many counts. But the regular 4-5 year election cycle puts short term gains over long term gains and rewards the interests of voters over non-voters, such as children or unborn generations. Those short term interests may be detrimental for the long term of the next 50–300 years. The failure to reach a global agreement on climate change at COP25 is a case in point. Of course, this failure is not limited to liberal democracies.
In political theory, have any systems been proposed to amend liberal democracy and build in ways to systemically consider more long term interests that may be of immediate concern to voters (or even require painful measures for the next years)?