Sure. By 2040, we estimate over $100 trillion of investment will be required to repair, modernize, and build new infrastructure assets critical to societies around the globe. The landmark Inflation Reduction Act passed earlier this year that had a direct and indirect support for renewable energy assets is just a small part of the global super cycle of infrastructure investment spending, which is likely to occur over the next 20 years.
The spending is not going to come from governments, but government policies can incentivize investment. Much of the necessary investment will actually come from the publicly traded companies that we can invest in through MEGI. Utilities, toll road operators, pipeline companies, and others will invest in existing and new infrastructure to meet the growing needs related to our mega trends. Those investments will help drive growth in earnings and income over time. The counter cyclical investment needs and the visibility of returns on the investments are the critical components that support our ongoing dividends at MEGI.
Taking the mega trends one by one. Decarbonization is the most prevalent in the MainStay CBRE Global Infrastructure Mega Trends Fund. We believe decarbonization is an unimpeachable theme. Over 70% of the global economy has a net zero carbon emissions target. It's not just the countries. It is multinational corporations and individuals driving this trend. The investment required in this area is the greatest of any sector. To meet our climate goals, utilities are investing heavily across the spectrum of clean energy infrastructure assets, including wind, solar, battery storage, and smart grid technology. This investment is driving a long runway of growth in company cash flows and dividends. Just over 50% of our portfolio is tied to this decarbonization mega trend.
Asset modernization is the second mega trend. Infrastructure assets don't just need to be repaired, although they certainly do need that, but they need to be modernized to meet today's new economy standards. Within this theme, we are investing in water utilities, gas utilities, midstream corporations and transportation infrastructure companies. Approximately 30% of our portfolio is tied to asset modernization.
The third mega trend is digital transformation. The tech innovators driving the transformation to all things digital pay rent to digital infrastructure companies. Fiber networks, towers, satellites, and data center assets must be expanded to meet the need for more space from these technology companies. As the tech innovators grow, they will pay more rent to our companies, which will grow their cash flow. Approximately 15% of our portfolio is invested in digital transformation related stocks.
We see opportunities for companies across the globe tied to these mega trends. Getting exposure to these themes requires a global portfolio in our view, and the current portfolio is allocated approximately 56% to stocks outside the US. But importantly, less than 6% into emerging markets. So we are talking about core infrastructure assets in developed markets with supportive regulatory environments.