Despite changes in regulatory policy, greenhouse gas emissions into the atmosphere have not decreased. A methodology for the search and selection of sources of financing for activities to combat climate change is proposed. The basis of the research methodology is the bibliometric and predictive analysis of the generated databases. It is proposed to use not only environmental tax revenues but also other sources of financing as part of mixed capital. It was revealed that the dynamics of environmental tax revenues are inferior to the dynamics of total tax revenues in GDP. The largest share of environmental taxes belongs to transport and energy taxes. The use of logical and predictive research approaches demonstrated that environmental revenues were insufficient and that extra funding and financial outsourcing were required for climate change activities. As a result of the correlation analysis, the most significant environmental revenues were for the following countries: France (0.981), Belgium (0.976), Greece (0.976), Austria (0.972), and Portugal (0.969). A negative Pearson correlation coefficient occurred for the countries: Denmark (-0.040), and Sweden (-0.101). To increase the significance of the coefficient, it is proposed to change the elements of environmental taxes in these countries. An outsourcer providing financial services to clients forms a regional environmental financial system. This will increase the rate of capital turnover and reduce the need for capital. The outsourcer will reduce "cash gaps" by promptly attracting financial tools and financial management techniques, accelerate the turnover period of mixed capital, and boost the effectiveness of managing environmental tax revenues.