  The retirement of unabated coal power plants, the plummeting cost of
renewable energy technologies, along with more aggressive public policies and
regulatory reforms, are occurring at an unprecedented speed to decarbonize the
power and energy systems towards the 2030 and 2050 climate goals. This article
aims to establish a carbon-oriented framework to examine the role carbon
emission is playing within a power grid that is rapidly transitioning to an
integrated multi-energy system. We divide the carbon flows in the multi-energy
systems into three stages: carbon allowances initialization/allocation,
exchanging/pricing, and circulation. Then, we discuss how cross-disciplinary
technologies, such as game theory, optimization, and machine learning can
facilitate the modeling and analysis of the proposed framework.
