Combatting climate change requires immediate, tangible actions from all countries. Greenhouse gas emissions reduction, adaptation to rules on lower greenhouse gas emissions, financing mitigation and adaptation, technology development and transfer, loss and damage due to climate risks and mitigation efforts, transparency and accountability for greenhouse gas emissions are key elements of effective climate policy. The United Nations Framework Convention on Climate Change and the Paris Agreement are two main multilateral treaties for establishing a common language, understandings, commitments and solutions. Among all these actions climate finance is the most critical factor for enabling required actions. Both public and private finance mobilization with transparent reporting is one grey area in climate change. Initiatives for corporates and non-state actors have been trying to disclosure their actions according to corporate social responsibility or quasi-climate-friendly ratings. However, each rating institutions measure or report the how well the corporates perform particularly environmental social and governance (ESG) in a various way. One common scaling and metric might not seem to be urgently adjusted for the ranking of the ESG of corporates, but existing rating institutions will be demanded a common format or template for climate finance in ESG reporting. Besides, recently established in the COP-26, a special group namely International Sustainability Standards Board has been working on a global baseline for climate-related financial disclosure. This kind of baseline is so critical in developing countries and emerging economies for effective climate financial mobilization without greenwashing. The aim of this study is to overview and compare the current ESG rating and reporting for the sake of effective climate finance mobilization and investments without greenwashing. This study also assesses how ESG scores affect the investment decisions toward the transformation of green and low-carbon energy. This chapter is limited to available data from rating institutions including Bloomberg, S&P, MSCI, and Sustainalytics. It is highly recommended that a common ESG reporting guide or approach will provide transparent disclosure to all. The future of ESG will be shaped by investor consciousness on global risks such as climate change and opportunities including green transformation.