Climate change is a global issue, therefore we need global solutions to resolve it - for this purpose the Clean Development Mechanism(CDM) has been set up under the Kyoto protocol back in 1997 and ratified by 192 countries (almost all countries), it sets standards, emissions allowance and principles, that, if followed, would help us reduce the greenhouse gases globally. Not long after the concept of CO2 neutrality has been adopted by businesses and started to be used to communicate to the public that a company, product or a process does not contribute to emitting any CO2, not a single gram. Naturally a question arises - how could a transportation company, farmer or a local supermarket not emit a single unit of CO2?

While emissions in some activities can be reduced (e.g. switching to electric vehicles (EV), efficient equipment and low energy freezers) some are practically impossible to avoid (e.g. buying food, clothes, using electricity). The good side of the story here is - what we cannot avoid (reduce or reuse), we can offset - or in other terms just reduce the emissions elsewhere for what you have emitted here (e.g. support a wind farm development or a reforestation project in a developing country that reduce or avoid additional CO2 emissions).

Source: https://cruiseshipprofiles.com/2019/11/09/msc-cruises-to-become-the-worlds-first-global-cruise-line-to-go-carbon-neutral/